Journal articles on the topic 'Optimal Switching Waveform'
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1
Mittet, Rune, and Tor Schaug-Pettersen. "Shaping optimal transmitter waveforms for marine CSEM surveys." GEOPHYSICS 73, no. 3 (May 2008): F97—F104. http://dx.doi.org/10.1190/1.2898410.
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The square wave is frequently used as the transmitter waveform in marine controlled-source electromagnetics (CSEM) surveys. This waveform has the advantage of transferring maximum energy to the subsurface because the transmitter current is running at its peak amplitude at all times. However, a limitation of the square wave is that most of the transmitted energy is in the first harmonic. Processing methods such as depth migration and inversion have shown improved results if a transmitter waveform with substantial amounts of energy at multiple frequencies is used. We propose a method for designing transmitter waveforms where current amplitudes as a function of frequency can have an approximate predefined or desired distribution. At the same time, we require that the transmitter operate at its peak current at all times to maximize the energy transferred to the subsurface. To obtain the desired current spectra, the number of switching times in a period is allowed to be larger than two, which is the number of switching times per period for a standard square wave. The method is based on matching the desired frequency spectra with the spectra obtained from these generalized square waves. This optimization problem is solved by a Monte Carlo method. The resultant waveforms can be used for an electric-dipole transmitter.
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Zhao, Chen Xu, Xin Guo, Tao Deng, Ling Li, and Ze Wen Liu. "Automated and Optimal Actuation Voltage Waveform Design for Contact Bouncing Mitigation of MEMS Switches." Key Engineering Materials 609-610 (April 2014): 1248–53. http://dx.doi.org/10.4028/www.scientific.net/kem.609-610.1248.
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This paper presents an efficient methodology for automated optimal tailoring actuation voltage waveform of MEMS switches aiming at eliminating the detrimental contact bouncing effect to speed up the switching process and improve the mechanical reliability. This is a simulation-based approach where genetic algorithm (GA) is used in combination with a dedicated mechanical model of MEMS switch to derive optimal actuation waveform. The proposed technique has been implemented in SystemC-A, which is extremely well suited for complex modeling, implementation of post-processing of simulation results and optimization algorithms. Effectiveness of proposed approach is corroborated by a practical case study of automated actuation waveform design for a prefabricated DC-contact MEMS switch. The experimental results show that the switching time of the switch by employing optimized actuation voltage waveform is dramatically reduced to 60μs from 95μs, while the bouncing effect is successfully eliminated.
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Priandana, Eka Rakhman, and Toshihiko Noguchi. "Pure Sinusoidal Output Single-Phase Current-Source Inverter with Minimized Switching Losses and Reduced Output Filter Size." Electronics 8, no. 12 (December 17, 2019): 1556. http://dx.doi.org/10.3390/electronics8121556.
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This paper proposes a novel single-phase current-source inverter that generates a pure sinusoidal waveform with minimized switching losses and using a small-size output filter capacitor. The proposed method is investigated by incorporating a conventional multilevel current-source inverter with a linear amplifier. The conventional multilevel technique uses fundamental switching frequency instead of using high-switching frequency modulation for the H-bridge circuit. The linear amplifier such as class-A or class-D types has a function to reform the staircase waveform generated by the multilevel inverter into a pure sinusoidal by using superimposition technique. As a result, pure sinusoidal output current is generated with a small ripple and the system only requires a small output filter capacitor for smoothing the waveform. Based on the simulation and experimental results, the proposed system presents not only the optimal configuration, but also an option as to whether to obtain excellent power efficiency or very low output harmonic. Implications of the results and future research directions are also presented.
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Marín-Reyes, Manuel, Jesus Aguayo-Alquicira, and Susana Estefany De León-Aldaco. "Calculation of Optimal Switching Angles for a Multilevel Inverter Using NR, PSO, and GA- a Comparison." European Journal of Electrical Engineering 22, no. 4-5 (October 30, 2020): 349–55. http://dx.doi.org/10.18280/ejee.224-506.
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Currently, multilevel inverters have been increased the number of applications in the industrial sector and renewable energy sources. Among its characteristics, the most remarkable are modular design, high performance, and low harmonic distortion in the output voltage waveform. For this paper, a single-phase Cascade H-Bridge Multilevel Inverters (CHB-MLI or CMLI) topology with independent DC sources, has been selected for the case study. Analyzing three scenarios: 5-level, 7-level, and 9-level applying the concept of the Optimized Harmonic Stepped-Waveform (OHSW) and comparing the results between the Selective Harmonic Eliminated-Pulse Width Modulation (SHE-PWM) and the Optimal Minimization of the Total Harmonic Distortion (OMTHD) are also presented. To compare the results obtained with classical and nature-inspired optimization methods, three techniques are used to solve transcendental nonlinear equations for the problem of Total Harmonic Distortion (THD) minimization: Newton Raphson (NR), Genetic Algorithm (GA), and Particle Swarm Optimization (PSO), which have been widely used for the problems of THD minimization in multilevel inverters.
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Zhang, Qingfei, Jinghong Zhao, Sinian Yan, Yiyong Xiong, Yuanzheng Ma, and Hansi Chen. "Virtual Voltage Vector-Based Model Predictive Current Control for Five-Phase Induction Motor." Processes 10, no. 10 (September 23, 2022): 1925. http://dx.doi.org/10.3390/pr10101925.
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The high-performance control technology of multi-phase motors is a key technology for the application of multi-phase motors in many fields, such as electric transportation. The model predictive current control (MPCC) strategy has been extended to multi-phase systems due to its high dynamic performance. Model-predictive current control faces the problem that it cannot effectively regulate harmonic plane currents, and thus cannot obtain high-quality current waveforms because only one switching state is applied in a sampling period. To solve this problem, this paper uses the virtual vector-based MPCC to select the optimal virtual vector and apply it under the premise that the average value of the harmonic plane voltage in a single switching cycle is zero. Taking a five-phase induction motor as an example, the steady-state and dynamic performance of the proposed virtual vector MPCC and the traditional model predictive current control were simulated, respectively. Simulation results demonstrated the effectiveness of the proposed method in improving waveform quality while maintaining excellent dynamic performance.
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Inostroza-Osses, Mauricio A., Oswaldo López-Santos, Yeison A. Aldana-Rodríguez, and Manuel G. Forero. "Alternative Generation of the Output Voltage Waveform in an Asymmetric Transformer-Based Cascaded Multilevel Inverter under Fault Conditions." Mathematics 10, no. 19 (September 23, 2022): 3463. http://dx.doi.org/10.3390/math10193463.
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This paper introduces a method for the reconfiguration of a transformer-based cascaded multilevel inverter (CT-MLI), which allows the use of alternative switching patterns when individual inverter stages cease to operate as a result of a failure in the circuit switches. Different possibilities of reconfiguration of the inverter stages to provide the output voltage signal are analyzed and optimal switching patterns are determined. The results obtained from the simulation in the PSIM software are provided to validate the proposal.
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DAHIDAH, MOHAMED S. A. "SELECTIVE HARMONIC ELIMINATION NON-SYMMETRICAL BIPOLAR PULSE WIDTH MODULATION TECHNIQUE: ANALYSIS AND EXPERIMENTAL VERIFICATION." Journal of Circuits, Systems and Computers 19, no. 03 (May 2010): 719–31. http://dx.doi.org/10.1142/s0218126610006396.
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Selective harmonic elimination pulse width modulation (SHE-PWM) techniques offer a tight control of the harmonic spectrum of a given voltage waveform generated by a power electronic converter along with a low number of switching transitions. These optimal switching transitions can be calculated through Fourier theory, and for a number of years quarter-wave and half-wave symmetries have been assumed when formulating the problem. It is shown recently that symmetry requirements can be relaxed as a constraint. This changes the way the problem is formulated and different solutions can be found without a compromise. This paper reports solutions to the switching transitions of a bipolar SHE-PWM when both the quarter- and half-wave symmetries are abolished. Selected simulation and experimental results are reported to show the effectiveness of the proposed method.
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Jinesh, C., Chandla Ellis, and A. Alhamdhu Nisha. "Harmonic Reduction in 3 Phase Diode Clamped Multilevel Inverter by Capacitor Voltage Balancing Using SVM and Fuzzy Controller." Applied Mechanics and Materials 626 (August 2014): 164–66. http://dx.doi.org/10.4028/www.scientific.net/amm.626.164.
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Multilevel converters are effective means of reducing harmonic distortion and dv/dt of the output voltages, which makes this technology applicable to utility interface and drives. In this paper, Multilevel Converter for power conversion is proposed. The voltage balancing at the terminal is achieved through proper selection of switching states. The switching scheme is defined by Space Vector Modulation. A fuzzy controller need to be interfaced with the system using SVM for optimal voltage operation and error minimization .The main feature of the proposed SVM switching strategy is that it enables balancing voltages of the dc capacitors, with no requirement of additional controls or auxiliary devices and higher magnitude of ac-side voltage with reduced harmonic concept in the output waveform. The proposed idea is demonstrated in simulation to evaluate the validity of the concept in MATLAB.
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Rasheed, Mohammed, Moataz M. A. Alakkad, Rosli Omar, Marizan Sulaiman, and Wahidah Abd Halim. "Enhance the accuracy of control algorithm for multilevel inverter based on artificial neural network." Indonesian Journal of Electrical Engineering and Computer Science 20, no. 3 (December 1, 2020): 1148. http://dx.doi.org/10.11591/ijeecs.v20.i3.pp1148-1158.
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<p>In converters or multilevel inverters it is very important to ensure that the output of the<br />multilevel inverters waveforms in term of the voltage or current of the waveforms is<br />smooth and without distortion. The artificial neural network (ANN) technique to<br />obtaining proper switching angles sequences for a uniform step asymmetrical modified<br />multilevel inverter by eliminating specified higher-order harmonics while maintaining<br />the required fundamental voltage and current waveform. However, through this paper a<br />modified CHB-MLI are proposed using artificial intelligence optimization technique<br />based on modulation Selective Harmonic Elimination (SHE-PWM). A most powerful<br />modulation technique that used to minimize a harmonic contants during the outout<br />waveform of multilevel inverter is a SHE-PWM method. The proposed a five-level<br />Modified Cascaded H-Bridge Multilevel Inverter (M-CHBMI) with ANN controller to<br />improve the output voltage and current performance and achieve a lower Total<br />Harmonic Distortion (THD). The main aims of this paper cover design, modeling,<br />prediction for real-time generation of optimal switching angles in a single-phase<br />topology of modified five level CHB-MLI. due to the heavy cost of computation to<br />solving transcendental nonlinear equations with specified number, a real-time<br />application of Selective Harmonic Elimination-Pulse Width Modulation (SHE-PWM)<br />technique is limited. SHE equations known as a transcendental nonlinear equation that<br />contain trigonometric functions. The prototype of a 5-level inverter in Digital Signal<br />Processing (DSP) TMS320F2812 reveals that the proposed method is highly efficient<br />for harmonic reduction in modified multilevel inverter.</p>
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Osama Y. AL-Rawi. "SWITCHING ANGLE OPTIMIZATION BASED GENETIC ALGORITHMS FOR HARMONIC REDUCTION IN THREE-PHASE PWM STRATEGY." Diyala Journal of Engineering Sciences 4, no. 1 (June 1, 2011): 83–94. http://dx.doi.org/10.24237/djes.2011.04106.
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In variable speed drive (VSD), it is desirable to reduce the harmonic effects, which causes current distortion and torque pulsation, besides, the harmonic power losses is an additional power losses that is introduced in the motor due to the presence of harmonic voltages.
However, the problem of the high total harmonic current distortion (THD) still exists specially at low and medium speeds by using sub-optimal pulse width modulation (PWM) strategy. In the past to generate optimized PWM, is done by defining a general PWM in terms of a set of switching angles. Which result in a set of nonlinear equations in terms of the unknown switching angles. These equations are nonlinear as well as transcendental in nature. There is no efficient method that can be applied to solve such equations. The practical method of solving these equations is a trial and error process. Taking all the factors into account, a numerical technique can be applied to solve these set of nonlinear equations, but with some limitations.
To overcome these limitations, Genetic algorithms (GAs) serves to search for optimal switching angles setting. In addition, the (THD) will be reduced, this lead to obtain the optimal PWM waveform and to simplify the practical implementation, and then improving the performance of the system output.
GAs were employed as a search and optimization engine. Normally the tuning of the switching angles is a trail and error problem.
In this paper, GAs provides a much simpler approach to off-line tuning of PWM switching angles than the rather complicated non-genetic optimization algorithms
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Kuder, Manuel, Anton Kersten, Jose-Luis Marques-Lopez, Julian Estaller, Johannes Buberger, Florian Schwitzgebel, Torbjörn Thiringer, et al. "Capacitor Voltage Balancing of a Grid-Tied, Cascaded Multilevel Converter with Binary Asymmetric Voltage Levels Using an Optimal One-Step-Ahead Switching-State Combination Approach." Energies 15, no. 2 (January 13, 2022): 575. http://dx.doi.org/10.3390/en15020575.
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This paper presents a novel capacitor voltage balancing control approach for cascaded multilevel inverters with an arbitrary number of series-connected H-Bridge modules (floating capacitor modules) with asymmetric voltages, tiered by a factor of two (binary asymmetric). Using a nearest-level reference waveform, the balancing approach uses a one-step-ahead approach to find the optimal switching-state combination among all redundant switching-state combinations to balance the capacitor voltages as quickly as possible. Moreover, using a Lyapunov function candidate and considering LaSalle’s invariance principle, it is shown that an offline calculated trajectory of optimal switching-state combinations for each discrete output voltage level can be used to operate (asymptotically stable) the inverter without measuring any of the capacitor voltages, achieving a novel sensorless control as well. To verify the stability of the one-step-ahead balancing approach and its sensorless variant, a demonstrator inverter with 33 levels is operated in grid-tied mode. For the chosen 33-level converter, the NPC main-stage and the individual H-bridge modules are operated with an individual switching frequency of about 1 kHz and 2 kHz, respectively. The sensorless approach slightly reduced the dynamic system response and, furthermore, the current THD for the chosen operating point was increased from 3.28 to 4.58 in comparison with that of using the capacitor voltage feedback.
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Zhang, Yun, Liang Chen, Zhixue Wang, and Enguang Hou. "Speed Control of Switched Reluctance Motor Based on Regulation Region of Switching Angle." Energies 15, no. 16 (August 9, 2022): 5782. http://dx.doi.org/10.3390/en15165782.
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This paper studies the speed control strategy of a switched reluctance motor based on angle-position control (APC). The switched reluctance motor has three control parameters: turn-on angle, turn-off angle and voltage PWM duty cycle. This paper studies the function of the three parameters and designs the control algorithms of the parameters, respectively, which can reduce the coupling degree, simplify the control process, and realize the optimal control of the switched reluctance motor. By studying the nonlinear characteristics of the switched reluctance motor, the optimal current waveform in the effective working range of the inductor is obtained, and then a control strategy of the turn-on angle is designed to realize the ideal winding current waveform. According to the torque characteristics of the motor, taking the coincidence of the freewheeling zero point and the position angle at the end of the maximum inductance interval as the control target, a control strategy for the turn-off angle that makes full use of the effective inductance working interval is proposed, which improves the efficiency of the system. For the nonlinear and time-variant switched reluctance motor running process, a data-driven model-free adaptive control algorithm is introduced, and a switched reluctance motor speed control algorithm based on voltage PWM duty cycle is designed. The main contribution of this paper is to propose a control strategy that is generally applicable to switched reluctance motors, which does not depend on the precise mathematical model of the motor. The control algorithms are designed separately for the three control parameters according to the characteristics of the motor, which reduces the degree of coupling among them. A switched reluctance motor drive system based on angle-position control is designed. This strategy is especially suitable for driving the load with sudden large torque pulsation.
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Kang, Longyun, Jianbin Zhang, Hailan Zhou, Zixian Zhao, and Xinwei Duan. "Model Predictive Current Control with Fixed Switching Frequency and Dead-Time Compensation for Single-Phase PWM Rectifier." Electronics 10, no. 4 (February 9, 2021): 426. http://dx.doi.org/10.3390/electronics10040426.
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The research object of this paper is single-phase PWM rectifier, the purpose is to reduce the total harmonic distortion (THD) of the grid-side current. A model predictive current control (MPCC) with fixed switching frequency and dead-time compensation is proposed. First, a combination of an effective vector and two zero vectors is used to fix the switching frequency, and a current prediction equation based on the effective vector’s optimal action time is derived. The optimal action time is resolved from the cost function. Furthermore, in order to perfect the established prediction model and suppress the current waveform distortion as a consequence of the dead-time effect, the dead-time’s influence on the switching vector’s action time is analyzed, and the current prediction equation is revised. According to the experimental results, the conclusion is that, firstly, compared with finite-control-set model predictive control, proportional-integral-based instantaneous current control (PI-ICC) scheme and model predictive direct power control (MP-DPC), the proposed MPCC has the lowest current THD. In addition, the proposed MPCC has a shorter execution time than MP-DPC and has fewer adjusted parameters than PI-ICC. In addition, the dead-time compensation scheme successfully suppresses the zero-current clamping effects, and reduce the current THD.
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Aljafari, Belqasem, Kanagavel Rameshkumar, Vairavasundaram Indragandhi, and Selvamathi Ramachandran. "A Novel Single-Phase Shunt Active Power Filter with a Cost Function Based Model Predictive Current Control Technique." Energies 15, no. 13 (June 21, 2022): 4531. http://dx.doi.org/10.3390/en15134531.
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For a single-phase Shunt Active Power Filter (SAPF) with a two-step prediction, this research presents a modified current control based on a Model Predictive Current Control (MPCC) technique. An H-bridge inverter, a DC link capacitor, and a filter inductor comprise the single-phase SAPF topology. The SAPF reference current is computed using the DC-link capacitor voltage regulation-based PI control technique. The weighting factor-based model predictive current controller is used to track the current commands. The essential dynamic index for evaluating waveform quality is the Total Harmonic Distortion (THD) of a source current and switching frequency of power switches. The conventional methods the THD and switching frequency are not considered as an objective function, so that a weighting factor-based MPCC technique is used to obtain a good compromise between the THD of the source current and switching frequency of power switches. Through MATLAB simulation and experimentation with the Cyclone-IV EP4CE30F484 FPGA board, the usefulness of the proposed control technique is proven. As compared with hysteresis, predictive PWM, and conventional MPCC control methods, the cost function-based MPCC algorithm provides a lower switching frequency (13.4 kHz) with an optimal source current THD value.
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Omran, Khulood, Abdul-Basset Al-Hussein, and Basil Jassim. "Optimal Learning Controller Design Using Particle Swarm Optimization: Applied to CSI System." Iraqi Journal for Electrical and Electronic Engineering 16, no. 1 (June 7, 2020): 104–12. http://dx.doi.org/10.37917/ijeee.16.1.13.
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In this article, a PD-type iterative learning control algorithm (ILC) is proposed to a nonlinear time-varying system for cases of measurement disturbances and the initial state errors. The proposed control approach uses a simple structure and has an easy implementation. The iterative learning controller was utilized to control a constant current source inverter (CSI) with pulse width modulation (PWM); subsequently the output current trajectory converged the sinusoidal reference signal and provided constant switching frequency. The learning controller's parameters were tuned using particle swarm optimization approach to get best optimal control for the system output. The tracking error limit is achieved using the convergence exploration. The proposed learning control scheme was robust against the error in initial conditions and disturbances which outcome from the system modeling inaccuracies and uncertainties. It could correct the distortion of the inverter output current waveform with less computation and less complexity. The proposed algorithm was proved mathematically and through computer simulation. The proposed optimal learning method demonstrated good performances.
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Francis, Roy, and D. Meganathan. "An Improved ANFIS with Aid of ALO Technique for THD Minimization of Multilevel Inverters." Journal of Circuits, Systems and Computers 27, no. 12 (June 22, 2018): 1850193. http://dx.doi.org/10.1142/s0218126618501931.
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In this study, an artificial intelligent (AI) technique is proposed for minimizing the total harmonic distortion (THD) of the multi-level inverter (MLI). An AI technique is a mixture of an ALO and ANFIS, which controls the parameters of the inverter. The innovation of the proposed technique is improving the performance of the MLI, which is reducing the THD based on the output voltage waveform. Normally, the output voltage of the inverter is based on the switching angle of MLI. Then the proposed technique is utilized to optimize the switching angle and THD of the inverter. Here, the ALO is used to analyze the switching angle of the MLI with the aid of the fitness function. ANFIS is familiar with optimizing the switching angle from the ALO algorithm output. By the implementation of the proposed technique, decrease the value of THD in the MLI for gathering the performance of the system. Asymmetrical MLI is used in the proposed model and it wishes to separate DC supply to activate. For skilled activation, the optimal outcomes and the objective functions are well-definite and recognize their restriction similarly. The proposed technique was realized in MATLAB/Simulink platform and compared with the prevailing techniques such as particle swarm optimization (PSO)-ANFIS, genetic algorithm (GA)-Artificial Neural Networks (ANN) and ANN-ALO.
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Feyrouz Abdelgoui, Rim, Rachid Taleb, Abderrahim Bentaallah, and Fayçal Chabni. "Harmonic Elimination in Uniform Step Nine-Level Inverter Using Differential Evolution: Experimental Validation." Electronics ETF 25, no. 1 (June 15, 2021): 31–36. http://dx.doi.org/10.53314/els2125031a.
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This study presents the application of differential evolution algorithm to compute optimal switching angles for a single-phase nine-level inverter to improve the output voltage quality. The topology of the proposed inverter in this article is a simple cascade converter composed of two H-bridge cells with non-equal DC voltage sources in order to generate multiple voltage levels. Selective harmonic elimination pulse width modulation strategy is used to improve the generated AC output voltage waveform. The differential evolution optimization algorithm is used to solve non-linear transcendental equations necessary for the (SHPWM). Computational results obtained from computer simulations presented a good agreement with the theoretical predictions. A laboratory prototype based on STM32F407 microcontroller was built in order to validate the simulation results. The experimental results show the effectiveness of the proposed modulation method.
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Amarendra, Ch, and K. Harinadh Reddy. "Investigation and Analysis of Space Vector Modulation with Matrix Converter Determined Based on Fuzzy C-Means Tuned Modulation Indexs." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 5 (October 1, 2016): 1939. http://dx.doi.org/10.11591/ijece.v6i5.11378.
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<p>Matrix converter performs energy conversion by directly connecting input phases with output phases through bidirectional switches. Conventional power converters make use of bulky reactive elements which are subjected to ageing, reduce the system reliability. The matrix converter (MC) stands as an alternative to conventional power converter. Furthermore MC’s provide bidirectional power flow nearly sinusoidal input and sinusoidal output waveform and controllable input power factor. In this work, three modulation methods have been simulated using MATLAB and compared on the basis of input current harmonics, output voltage harmonics and number of switching per cycle. The three techniques simulated are, Optimal Venturini method, Direct Space Vector Modulation (DSVM) and Indirect Space Vector Modulation (ISVM) on Conventional Matrix Converter (CMC) and obtained form Fuzzy c-Means (FCM). DSVM with FCM is proposed for obtainting best results compared to other three techniques.</p>
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Amarendra, Ch, and K. Harinadh Reddy. "Investigation and Analysis of Space Vector Modulation with Matrix Converter Determined Based on Fuzzy C-Means Tuned Modulation Indexs." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 5 (October 1, 2016): 1939. http://dx.doi.org/10.11591/ijece.v6i5.pp1939-1947.
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<p>Matrix converter performs energy conversion by directly connecting input phases with output phases through bidirectional switches. Conventional power converters make use of bulky reactive elements which are subjected to ageing, reduce the system reliability. The matrix converter (MC) stands as an alternative to conventional power converter. Furthermore MC’s provide bidirectional power flow nearly sinusoidal input and sinusoidal output waveform and controllable input power factor. In this work, three modulation methods have been simulated using MATLAB and compared on the basis of input current harmonics, output voltage harmonics and number of switching per cycle. The three techniques simulated are, Optimal Venturini method, Direct Space Vector Modulation (DSVM) and Indirect Space Vector Modulation (ISVM) on Conventional Matrix Converter (CMC) and obtained form Fuzzy c-Means (FCM). DSVM with FCM is proposed for obtainting best results compared to other three techniques.</p>
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Ali Naghizadeh, Ramezan, Behrooz Vahidi, and Seyed Hossein Hosseinian. "Calculation of inrush current using adopted parameters of the hysteresis loop." COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 33, no. 5 (August 26, 2014): 1794–808. http://dx.doi.org/10.1108/compel-08-2012-0133.
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Purpose – The purpose of this paper is to propose an accurate model for simulation of inrush current in power transformers with taking into account the magnetic core structure and hysteresis phenomenon. Determination of the required model parameters and generalization of the obtained parameters to be used in different conditions with acceptable accuracy is the secondary purpose of this work. Design/methodology/approach – The duality transformation is used to construct the transformer model based on its topology. The inverse Jiles-Atherton hysteresis model is used to represent the magnetic core behavior. Measured inrush waveforms of a laboratory test power transformer are used to calculate a fitness function which is defined by comparing the measured and simulated currents. This fitness function is minimized by particle swarm optimization algorithm which calculates the optimal model parameters. Findings – An analytical and simple approach is proposed to generalize the obtained parameters from one inrush current measurement for simulation of this phenomenon in different situations. The measurement results verify the accuracy of the proposed method. The developed model with the determined parameters can be used for accurate simulation of inrush current transient in power transformers. Originality/value – A general and flexible topology-based model is developed in PSCAD/EMTDC software to represent the transformer behavior in inrush situation. The hysteresis model parameters which are obtained from one inrush current waveform are generalized using the structure parameters, switching angle, and residual flux for accurate simulation of this phenomenon in different conditions.
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Algaddafi, Ali, Saud A. Altuwayjiri, Oday A. Ahmed, and Ibrahim Daho. "An Optimal Current Controller Design for a Grid Connected Inverter to Improve Power Quality and Test Commercial PV Inverters." Scientific World Journal 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/1393476.
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Grid connected inverters play a crucial role in generating energy to be fed to the grid. A filter is commonly used to suppress the switching frequency harmonics produced by the inverter, this being passive, and either an L- or LCL-filter. The latter is smaller in size compared to the L-filter. But choosing the optimal values of the LCL-filter is challenging due to resonance, which can affect stability. This paper presents a simple inverter controller design with an L-filter. The control topology is simple and applied easily using traditional control theory. Fast Fourier Transform analysis is used to compare different grid connected inverter control topologies. The modelled grid connected inverter with the proposed controller complies with the IEEE-1547 standard, and total harmonic distortion of the output current of the modelled inverter has been just 0.25% with an improved output waveform. Experimental work on a commercial PV inverter is then presented, including the effect of strong and weak grid connection. Inverter effects on the resistive load connected at the point of common coupling are presented. Results show that the voltage and current of resistive load, when the grid is interrupted, are increased, which may cause failure or damage for connecting appliances.
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Alqattan, Husain, Dandan Hui, Vladimir Pervak, and Mohammed Th Hassan. "Attosecond light field synthesis." APL Photonics 7, no. 4 (April 1, 2022): 041301. http://dx.doi.org/10.1063/5.0082958.
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The advancement of the ultrafast pulse shaping and waveform synthesis allowed to coherently control the atomic and electronic motions in matter. The temporal resolution of the waveform synthesis is inversely proportional to the broadening of its spectrum. Here, we demonstrate the light field synthesis of high-power waveforms spanning two optical octaves, from near-infrared to deep-ultraviolet with attosecond resolution. Moreover, we utilized the all-optical field sampling metrology for on-demand tailoring of light field waveforms to control the electron motion in matter. The demonstrated synthesis of the light field and the electron motion control pave the way for switching the photo-induced current signal in dielectric nanocircuit and establishing ultrafast photonics operating beyond the petahertz speed.
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Faiza, Aouiouat A., Sebaa Morsli, and Allaoui Tayeb. "Self Tuning Filter Based Fuzzy Logic Controller for Active Power Filter." Journal Européen des Systèmes Automatisés 53, no. 5 (November 15, 2020): 739–45. http://dx.doi.org/10.18280/jesa.530517.
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The performance of the Active Power Filter (APF) depends on the identification strategy of the reference currents and their control. Among the control strategies proposed in the literature to identifying the reference currents, that based on Self Tuning Filter (STF) which allows extracting directly the voltage and current fundamental components in the α-β axis at high performances, without any Phase Locked Loop (PLL). The performance of STF is function of its proportional parameter. However, there is no technique existed in the literature to dimensioning the proportional parameter of the STF filter. This paper presents an improved method for identifying the reference harmonic currents to be generated by the APF, based on STF for the extraction of harmonic currents and equipped with a Fuzzy Logic Corrector (FLC) in order to improve the waveform of the electric lines currents. The FLC adjust in real time the proportional parameter of the STF filter. The proposed FLC-STF regulator allows to having an optimal extraction of the harmonic currents. The conventional hysteresis method was used for the current control technique to generate the switching sequences of the static switches of the APF voltage inverter. The obtained simulation results, performed under the MATLAB/Simulink® environment on a system feeding a non-linear load, show good performance.
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Farooq, Waqas, Muhammad J. Alvi, and Tahir Izhar. "Multiple Input Single Output DC to DC Converter Control Using Kalman Filter for Microgrid Applications." Proceedings of the Pakistan Academy of Sciences: A. Physical and Computational Sciences 58, no. 3 (February 3, 2022): 67–77. http://dx.doi.org/10.53560/ppasa(58-3)752.
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Renewable energy system (RES) based microgrid applications have grown extensively over the recent years. Owing to power fluctuations in RES, acquiring stable and accurate output voltage at the DC Bus is a major concern in DC microgrid applications. Presently, switching, as well as, prediction of output voltage for RES is quite slow and total harmonic distortion cannot be reduced to a minimal level. Accordingly, this research developed a controller for Multiple Input Single Output (MISO) DC to DC converter and a Kalman filter. Initially, four seriesconnected PV panels were modelled and analysed. A boost converter was used to combine PV panels' output and provide a single output at the DC Bus. Perturb and Observe, a Maximum Power Point Tracking (MPPT) algorithm, was used to retrieve optimal power from modelled RES. Analysis revealed that the output voltage waveform contained harmonics and had a Total Harmonic Distortion (THD) of 27.73 %. Thus, a Kalman filter was modeled and analysed to remove the harmonics. The THD value was consequently reduced to 2.1 %, which is quite within the allowable limit prescribed by IEEE, for the THD of a PV system. Analysis revealed that a stable and accurate output from a PV based RES could be achieved with the proposed scheme, and further THD was also well within limits prescribed by IEEE.
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Pan, Cheng-Tang, Shao-Yu Wang, Chun-Chieh Chang, Chung-Kun Yen, Jyun-Yi Wu, Shin-Pon Ju, and Roger Cheng-Lung Lee. "Improvement of Model Predictive Current Control Sensing Strategy for a Developed Small Flux-Switching Permanent Magnet Motor." Sensors 20, no. 11 (June 3, 2020): 3177. http://dx.doi.org/10.3390/s20113177.
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This paper presents an improved control system for a small flux-switching permanent magnet motor (FSPM) to enhance its performance and torque sensing. The analytical magnetic circuit design was used to determine the related motor parameters, such as the air gap flux density, permeance coefficient (Pc), torque, winding turns, pole number, width, length, magnet geometry, and the current density of FSPM. The electromagnetic analysis of this motor was performed by software (ANSYS Maxwell) to optimize the motor performance. In this study, the performance of FSPM was investigated by the uniform design experimentation (UDE). For the control system, the model predictive current control (MPCC) is currently recognized as a high-performance control strategy, due to its quick response and simple principle. This model contained the nonlinear part of the system, to improve the torque ripple of FSPM. A modified MPCC strategy was proposed to improve the distortion of the current waveform and decrease the computational burden. The new modified control architecture was mainly composed of three parts, such as the estimation of electromotive force (EMF), current prediction, and optimal vector selection/vector duration. When the reference voltage vector was obtained, the three-phase duties were easily determined by the principle of space vector modulation (SVM). The results show the different strategy methods between the newly proposed modified MPCC and traditional proportional integral (PI) controller. In the control of FSPM, a modified MPCC strategy was able to achieve a better performance response and decrease the computational burden. At a low speed of 350 rpm, the proposed modified MPCC can achieve a better dynamic response. The nonlinear problem of the startup speed was also effectively resolved. The torque sensing performance of the simulation and the experimental test value were compared. The torque sensing performance of the simulation and the actual test value were also examined. In this study, the optimization focused not only on the motor design and fabrication, but also on an improved motor control strategy and torque sensing, in order to achieve the integrity of the FSPM system.
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Haseeb, Abdul, Mahesh Edla, Mustafa Ucgul, Fendy Santoso, and Mikio Deguchi. "A Voltage Doubler Boost Converter Circuit for Piezoelectric Energy Harvesting Systems." Energies 16, no. 4 (February 6, 2023): 1631. http://dx.doi.org/10.3390/en16041631.
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This paper describes the detailed modelling of a vibration-based miniature piezoelectric device (PD) and the analysis modes of operation and control of a voltage doubler boost converter (VDBC) circuit to find the PD’s optimal operating conditions. The proposed VDBC circuit integrates a conventional voltage doubler (VD) circuit with a step-up DC-DC converter circuit in modes 1–4, while a non-linear synchronisation procedure of a conventional boost converter circuit is employed in modes 5–6. This integration acted as the voltage boost circuit without utilising duty cycles and complex auxiliary switching components. In addition, the circuit does not require external trigger signals to turn on the bidirectional switches. This facilitates the operation of VDBC circuit at very low AC voltage (Vac ≥ 0.5 V). Besides this, the electrical characteristics of VDBC circuit’s input (i.e., PD) perfectly concurs with the studied testing scenarios using impedance power sources (mechanical shaker). Firstly, the proposed circuit which can rectify the PD’s output was tested at both constant input voltage with varying excitation frequency and constant excitation frequency with varying input voltage. Next, a small-scale solar battery was charged to validate the feasibility of the performance of the proposed VDBC circuit. The proposed circuit achieved a maximum output voltage of 11.7 Vdc with an output power of 1.37 mW. In addition, the rectified voltage waveform is stable due to the sminimisation of the ripples. In addition, the performance of VDBC circuit was verified by comparing the achieved results with previously published circuits in the literature. The results show that the proposed VDBC circuit outperformed existing units as described in the literature regarding output voltage and power. The developed rectifier circuit is suitable for various real-life applications such as energy harvesting and battery charging.
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Di, Zhengfei, Demin Xu, and Kehan Zhang. "Continuous Control Set Model Predictive Control for an Indirect Matrix Converter." Energies 14, no. 14 (July 8, 2021): 4114. http://dx.doi.org/10.3390/en14144114.
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A continuous control set model predictive power control strategy for an indirect matrix converter is proposed in this paper. The load reactive power, the load active power, and the input reactive power are controlled simultaneously. This control strategy can obtain output waveforms with fixed switching frequency. Additionally, an optimal switching sequence is proposed to simplify the commutations of the indirect matrix converter. To suppress the input filter resonance, an active damping method is proposed. Experimental results prove that the proposed method features controllable input reactive power, controllable load active and reactive power, fixed switching frequency output waveforms, zero-current switching operations, and effectively suppresses input filter resonance.
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He, Tingting, Nicolas K. Fontaine, Ryan P. Scott, David J. Geisler, Jonathan P. Heritage, and S. J. B. Yoo. "Optical Arbitrary Waveform Generation-Based Packet Generation and All-Optical Separation for Optical-Label Switching." IEEE Photonics Technology Letters 22, no. 10 (May 2010): 715–17. http://dx.doi.org/10.1109/lpt.2010.2044658.
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Fiaz, Muhammad Faisal, Sandro Calligaro, Mattia Iurich, and Roberto Petrella. "Analytical Modeling and Control of Dual Active Bridge Converter Considering All Phase-Shifts." Energies 15, no. 8 (April 7, 2022): 2720. http://dx.doi.org/10.3390/en15082720.
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In the field of power electronics-based electrical power conversion, the Dual Active Bridge (DAB) topology has become very popular in recent years due to its characteristics (e.g., bidirectional operation and galvanic isolation), which are particularly suitable to applications such as interface to renewable energy sources, battery storage systems and in smart grids. Although this converter type has been extensively investigated, its analysis and control still pose many challenges, due to the multiple control variables that affect the complex behavior of the converter. This paper presents a theoretical model of the single-phase DAB converter. The proposed model is very general, i.e., it can consider any modulation technique and operating condition. In particular, the converter is seen as composed by four legs, each capable of generating voltage on the inductor, and by the two output legs, which can steer the resulting inductor current to the load. Three variables are considered as the control inputs, i.e., the phase-shifts with respect to one leg. This approach results in a very simple yet accurate closed-form algorithm for obtaining the inductor current waveform. Moreover, a novel analytical model is proposed for calculating the average output current, based on the phase-shift values, independently of the output voltage. It is also shown that average output current can be varied cycle-by-cycle, with no further dynamics. In fact, average output current is not affected by the initial value of inductor current or by DC offset (which may arise during transients). The proposed models can be exploited at several stages of development of a DAB: during the design stage, for fast iteration, when selecting its operating points and when designing the control. In fact, based on the analytical results, a novel control loop is proposed, which adopts a “fictitious” (i.e., open-loop) inner current regulation loop, which can be applied to any modulation scheme (e.g., Single Phase-Shift, Triple Phase-Shift, etc.). The main advantage of this control scheme is that the simple dynamics of the output voltage versus the average output current can be decoupled from the complicated relationship between the phase-shifts and the output current. Moreover, a Finite Control Set (FCS) method is proposed, which selects the optimal operating points for each operating condition and control request, ensuring full Zero-Voltage Switching (ZVS) in all cases. The analytical results obtained and control methods proposed are verified through simulations and extensive experimental tests.
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Modi, Sankalp, Poras Balsara, and Oren Eliezer. "Envelope tracking using transient waveform switching shaping supply modulation." International Journal of Circuit Theory and Applications 43, no. 5 (December 13, 2013): 656–74. http://dx.doi.org/10.1002/cta.1966.
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Huang, Chaoqun, Jun Ou, and Hao Chi. "Generation of Switchable Chirp Waveforms in the Photonic Domain with Immunity to Dispersion-Induced Power Fading." Photonics 8, no. 11 (November 8, 2021): 501. http://dx.doi.org/10.3390/photonics8110501.
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A novel photonic approach to generating switchable multi-format chirp waveforms using a dual-drive dual-parallel Mach–Zehnder modulator (DD-DPMZM) is proposed and experimentally demonstrated. By properly controlling the bias voltage on the DD-DPMZM, different chirp RF waveforms, including the dual-, down-, and up-chirp waveforms, can be obtained when an RF signal and a chirp RF signal are injected into the modulator. A main feature of this approach is that it can eliminate chromatic dispersion-induced RF power fading, which is highly desired in distributed multi-functional radars based on radio over fiber. There is no polarization control and optical filtering in the given scheme, which also improves the stability and feasibility of the approach. An experiment successfully demonstrated the generation and switching of the multi-format chirp waveforms and the capability of immunity to dispersion-induced power fading.
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Sabirin, Nor Hidalina Mohd, Zainuddin Mat Isa, Mohd Hafiz Arshad, Baharuddin Ismail, Md Hairul Nizam Talib, and Ernie Che Mid. "Harmonics Elimination in 7-Level Multilevel Inverter Using Animal Migration Optimization Algorithm with Different Objective Functions." International Journal of Emerging Technology and Advanced Engineering 13, no. 1 (January 3, 2023): 18–27. http://dx.doi.org/10.46338/ijetae0123_03.
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Harmonics can degrade the power quality of a multilevel inverter by causing the voltage to be distorted and vary from sinusoidal waveforms. Harmonics can be reduced by increasing the number of voltage levels or by employing suitable modulation techniques. In this paper, The Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) modulation method is employed to obtain the optimal switching angles that able to reduce the specific individual harmonic and the Total Harmonic Distortion (THD) in singlephase 7-level Cascaded H-Bridge multilevel inverter. The Animal Migration Optimization (AMO) is proposed to acquire these angles using two difference objective functions. The performance is examined and evaluated. Both objective functions able to determine the optimal switching angles starting from modulation index of 0.34. However, the comparative study demonstratethat objective function number 2 has better performance in term of lowering selective individual harmonics as well as THD.
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Craven, J. M., E. Meeks, G. Delich, E. Ayars, H. K. Pechkis, and J. A. Pechkis. "A low-cost shutter driver and arbitrary waveform generator for optical switching using a programmable system-on-chip (PSoC) device." Review of Scientific Instruments 93, no. 11 (November 1, 2022): 113002. http://dx.doi.org/10.1063/5.0105884.
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We have developed a low-cost mechanical shutter driver with integrated arbitrary waveform generation for optical switching and control using a programmable system-on-chip device. This microcontroller-based device with configurable digital and analog blocks is readily programmed using free software, allowing for easy customization for a variety of applications. Additional digital and analog outputs with arbitrary timings can be used to control a variety of devices, such as additional shutters, acousto-optical modulators, or camera trigger pulses, for complete control and imaging of laser light. Utilizing logic-level control signals, this device can be readily integrated into existing computer control and data acquisition systems for expanded hardware capabilities.
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Zhang, Hongbin, Zhike Xu, Chenglei Liu, Long Jin, Haitao Yu, Bingxin Xu, and Shuhua Fang. "Novel Axial Flux-Switching Permanent Magnet Machine for High-Speed Applications." Sustainability 14, no. 13 (June 25, 2022): 7774. http://dx.doi.org/10.3390/su14137774.
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Conventional high-speed flux-switching machines have either a high fundamental frequency or more even harmonics. This paper proposes a novel six-slot four-pole axial flux-switching permanent magnet machine for high-speed applications. The machine, consisting of two radially distributed stators and one rotor, can effectively eliminate even harmonics in the flux linkage. First, the structural parameters that affect the performance of the motor are determined by the equivalent magnetic circuit method, and the optimal structural parameters of the motor are obtained by simulation optimization. Then, through finite element analysis, the three-dimensional model of the proposed machine is built, and the static electromagnetic characteristics are analyzed, including magnetic field distribution, flux linkage, back-electromotive force, cogging torque, and efficiency. The simulation results show that the total harmonic distortion of the flux linkage and back-electromotive force waveforms of the proposed novel machine is 2.2% and 9.8% respectively. The cogging torque of the optimal model is only 9 N.
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Marriott, Gerard, Shu Mao, Tomoyo Sakata, Jing Ran, David K. Jackson, Chutima Petchprayoon, Timothy J. Gomez, et al. "Optical lock-in detection imaging microscopy for contrast-enhanced imaging in living cells." Proceedings of the National Academy of Sciences 105, no. 46 (November 12, 2008): 17789–94. http://dx.doi.org/10.1073/pnas.0808882105.
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One of the limitations on imaging fluorescent proteins within living cells is that they are usually present in small numbers and need to be detected over a large background. We have developed the means to isolate specific fluorescence signals from background by using lock-in detection of the modulated fluorescence of a class of optical probe termed “optical switches.” This optical lock-in detection (OLID) approach involves modulating the fluorescence emission of the probe through deterministic, optical control of its fluorescent and nonfluorescent states, and subsequently applying a lock-in detection method to isolate the modulated signal of interest from nonmodulated background signals. Cross-correlation analysis provides a measure of correlation between the total fluorescence emission within single pixels of an image detected over several cycles of optical switching and a reference waveform detected within the same image over the same switching cycles. This approach to imaging provides a means to selectively detect the emission from optical switch probes among a larger population of conventional fluorescent probes and is compatible with conventional microscopes. OLID using nitrospirobenzopyran-based probes and the genetically encoded Dronpa fluorescent protein are shown to generate high-contrast images of specific structures and proteins in labeled cells in cultured and explanted neurons and in live Xenopus embryos and zebrafish larvae.
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Liu, Keyuan, Haibin Li, and Ya Wang. "An Optical Fiber Sensing Network Supporting Weak Optical Signal Detection and a Neural Network Method for Information Collection." Journal of Nanoelectronics and Optoelectronics 16, no. 2 (February 1, 2021): 188–95. http://dx.doi.org/10.1166/jno.2021.2923.
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The weak direct current (DC) signals detected and converted by the photodetector are output to the mobile phone by voltage/frequency switching, and the signals are processed by the mobile phone APP and audio conversion module. The photodetector is equipped with the automatic switching function to design an optical power meter and detect weak signals. Meanwhile, the optical cable identification system is analyzed and combined with the optical power meter to generate an optical fiber sensing network to improve the weak alternating current (AC) signal detection. This network needs data fusion in sensor nodes’ data collection. The cluster routing protocol is introduced and combined with the back propagation neural network (BPNN) to propose a method suitable for this photoelectric transmission and improve the information fusion and accuracy. In the experiment, the optical power meter is output in gears first, and the output waveforms are normal. The photodiode’s optical power is adjusted to obtain different frequencies on the oscilloscope. In the proposed optical fiber sensing network, weak AC signals are amplified significantly, and different optical fiber lines can be distinguished in the optical cables. The proposed information collection method can reduce network communication and node energy consumption.
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Li, Qiqi, Shanxu Duan, and Han Fu. "Analysis and Design of Single-Ended Resonant Converter for Wireless Power Transfer Systems." Sensors 22, no. 15 (July 27, 2022): 5617. http://dx.doi.org/10.3390/s22155617.
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Single-ended resonant converters such as Class-E inverters have been widely considered as a potential topology for small- and medium-power wireless power transfer (WPT) applications, which feature compact circuits, low switching losses, and cost benefits, as they only use a low-side switch with a simple gate driver. However, there remains a practical challenge in the design of voltage stress, efficiency, and power density. In this paper, a single-ended resonant converter with a primary parallel resonant-matching network is investigated to absorb the bulky input-choke inductors of the Class-E inverters into the coil inductance. The analytical expressions for all the converter parameters are derived based on time-domain resonant waveforms, including: (1) analysis of critical zero-voltage switching (ZVS) conditions and (2) power transfer capabilities under the given maximum switch voltage stress. Furthermore, this paper elaborates on the design methodology of the proposed single-ended resonant converters, and an optimal operating point is chosen to ensure soft-switching operation and rated power. Finally, the accuracy of the proposed model is verified by simulation and experimental results.
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Musumeci, Salvatore, Fabio Mandrile, Vincenzo Barba, and Marco Palma. "Low-Voltage GaN FETs in Motor Control Application; Issues and Advantages: A Review." Energies 14, no. 19 (October 6, 2021): 6378. http://dx.doi.org/10.3390/en14196378.
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The efficiency and power density improvement of power switching converters play a crucial role in energy conversion. In the field of motor control, this requires an increase in the converter switching frequency together with a reduction in the switching legs’ dead time. This target turns out to be complex when using pure silicon switch technologies. Gallium Nitride (GaN) devices have appeared in the switching device arena in recent years and feature much more favorable static and dynamic characteristics compared to pure silicon devices. In the field of motion control, there is a growing use of GaN devices, especially in low voltage applications. This paper provides guidelines for designers on the optimal use of GaN FETs in motor control applications, identifying the advantages and discussing the main issues. In this work, primarily an experimental evaluation of GaN FETs in a low voltage electrical drive is carried out. The experimental investigation is obtained through two different experimental boards to highlight the switching legs’ behavior in several operative conditions and different implementations. In this evaluative approach, the main GaN FETs’ technological aspects and issues are recalled and consequently linked to motion control requirements. The device’s fast switching transients combined with reduced direct resistance contribute to decreased power losses. Thus, in GaN FETs, a high switching frequency with a strong decrease in dead time is achievable. The reduced dead time impact on power loss management and improvement of output waveforms quality is analyzed and discussed in this paper. Furthermore, input filter capacitor design matters correlated with increasing switching frequency are pointed out. Finally, the voltage transients slope effect (dv/dt) is considered and correlated with low voltage motor drives requirements.
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PARK, JONG-HOON, HONG-JUNE PARK, BO-KYOUNG CHOI, OH-HYUN KIM, and SI-DON CHOI. "SIMULTANEOUS SWITCHING NOISE ANALYSIS OF A 16 MB × 9 DRAM SIMM MEMORY MODULE." International Journal of High Speed Electronics and Systems 06, no. 04 (December 1995): 647–68. http://dx.doi.org/10.1142/s0129156495000249.
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HSPICE simulations have been performed for a 16 Mb×9 SIMM memory module and the simultaneous switching noise has been investigated. The SPICE model of the SIMM memory module is made up of a PCB circuit model and a simplified DRAM chip model. To keep the SPICE simulation time within reasonable bounds, a simplified circuit model of a 16 Mb DRAM chip was generated by keeping the basic physical DRAM structure in the model including the bit-line sense amplifiers. The parameter values of the circuit elements in the simplified DRAM chip model were tuned to fit the measured transient supply current waveform of a commercial 16 Mb DRAM chip. The SIMM module was placed on a fabricated motherboard PCB and the simultaneous switching noise voltage on the motherboard VSS plane was measured. Good agreement between measurements and HSPICE simulations were observed.
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Kanta, Konstantina, Panagiotis Toumasis, Kostas Tokas, Ioannis Stratakos, Elissaios Alexis Papatheofanous, Giannis Giannoulis, Ioanna Mesogiti, et al. "Demonstration of a Hybrid Analog–Digital Transport System Architecture for 5G and Beyond Networks." Applied Sciences 12, no. 4 (February 17, 2022): 2122. http://dx.doi.org/10.3390/app12042122.
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In future mobile networks, the evolution of optical transport architectures enabling the flexible, scalable interconnection of Baseband Units (BBUs) and Radio Units (RUs) with heterogeneous interfaces is a significant issue. In this paper, we propose a multi-technology hybrid transport architecture that comprises both analog and digital-Radio over Fiber (RoF) mobile network segments relying on a dynamically reconfigurable optical switching node. As a step forward, the integration of the discussed network layout into an existing mobile infrastructure is demonstrated, enabling the support of real-world services through both standard digital and Analog–Intermediate- Frequency over Fiber (A-IFoF)-based converged fiber–wireless paths. Emphasis has been placed on the implementation of a real-time A-IFoF transceiver that is employed through a single embedded fully programmable gateway array (FPGA)-based platform that serves as an Ethernet to Intermediate Frequency (IF) bridge for the transmission of legacy traffic over the analog network segment. The experimental evaluation of the proposed concept was based on the dynamic optical routing of the legacy Common Public Radio Interface (CPRI), 1.5 GBaud analog-intermediate frequency-over-fiber (A-IFoF)/mmWave and 10 Gbps binary optical waveforms, showing acceptable error vector magnitude (EVM) values for the complex radio waveforms and error-free operation for binary optical streams, with Bit Error Rate (BER) values less than 10−9. Finally, the end-to-end proof-of-concept demonstration of the proposed solution was achieved through the delivery of 4K video streaming and Internet Protocol (IP) calls over a mobile core network.
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Mitsolidou, Charoula, Christos Vagionas, Agapi Mesodiakaki, Pavlos Maniotis, George Kalfas, Chris G. H. Roeloffzen, Paul W. L. van Dijk, Ruud M. Oldenbeuving, Amalia Miliou, and Nikos Pleros. "A 5G C-RAN Optical Fronthaul Architecture for Hotspot Areas Using OFDM-Based Analog IFoF Waveforms." Applied Sciences 9, no. 19 (September 28, 2019): 4059. http://dx.doi.org/10.3390/app9194059.
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Analog fronthauling is currently promoted as a bandwidth and energy-efficient solution that can meet the requirements of the Fifth Generation (5G) vision for low latency, high data rates and energy efficiency. In this paper, we propose an analog optical fronthaul 5G architecture, fully aligned with the emerging Centralized-Radio Access Network (C-RAN) concept. The proposed architecture exploits the wavelength division multiplexing (WDM) technique and multicarrier intermediate-frequency-over-fiber (IFoF) signal generation per wavelength in order to satisfy the demanding needs of hotspot areas. Particularly, the fronthaul link employs photonic integrated circuit (PIC)-based WDM optical transmitters (Txs) at the baseband unit (BBU), while novel reconfigurable optical add-drop multiplexers (ROADMs) cascaded in an optical bus are used at the remote radio head (RRH) site, to facilitate reconfigurable wavelength switching functionalities up to 4 wavelengths. An aggregate capacity of 96 Gb/s has been reported by exploiting two WDM links carrying multi-IF band orthogonal frequency division multiplexing (OFDM) signals at a baud rate of 0.5 Gbd with sub-carrier (SC) modulation of 64-QAM. All signals exhibited error vector magnitude (EVM) values within the acceptable 3rd Generation Partnership Project (3GPP) limits of 8%. The longest reach to place the BBU away from the hotspot was also investigated, revealing acceptable EVM performance for fiber lengths up to 4.8 km.
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Yan, Yuling, Chutima Petchprayoon, Shu Mao, and Gerard Marriott. "Reversible optical control of cyanine fluorescence in fixed and living cells: optical lock-in detection immunofluorescence imaging microscopy." Philosophical Transactions of the Royal Society B: Biological Sciences 368, no. 1611 (February 5, 2013): 20120031. http://dx.doi.org/10.1098/rstb.2012.0031.
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Optical switch probes undergo rapid and reversible transitions between two distinct states, one of which may fluoresce. This class of probe is used in various super-resolution imaging techniques and in the high-contrast imaging technique of optical lock-in detection (OLID) microscopy. Here, we introduce optimized optical switches for studies in living cells under standard conditions of cell culture. In particular, a highly fluorescent cyanine probe (Cy or Cy3) is directly or indirectly linked to naphthoxazine (NISO), a highly efficient optical switch that undergoes robust, 405/532 nm-driven transitions between a colourless spiro (SP) state and a colourful merocyanine (MC) state. The intensity of Cy fluorescence in these Cy/Cy3-NISO probes is reversibly modulated between a low and high value in SP and MC states, respectively, as a result of Förster resonance energy transfer. Cy/Cy3-NISO probes are targeted to specific proteins in living cells where defined waveforms of Cy3 fluorescence are generated by optical switching of the SP and MC states. Finally, we introduce a new imaging technique (called OLID-immunofluorescence microscopy) that combines optical modulation of Cy3 fluorescence from Cy3/NISO co-labelled antibodies within fixed cells and OLID analysis to significantly improve image contrast in samples having high background or rare antigens.
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Jumani, Touqeer, Mohd Mustafa, Madihah Rasid, Nayyar Mirjat, Mazhar Baloch, and Sani Salisu. "Optimal Power Flow Controller for Grid-Connected Microgrids using Grasshopper Optimization Algorithm." Electronics 8, no. 1 (January 19, 2019): 111. http://dx.doi.org/10.3390/electronics8010111.
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Despite the vast benefits of integrating renewable energy sources (RES) with the utility grid, they pose stability and power quality problems when interconnected with the existing power system. This is due to the production of high voltages and current overshoots/undershoots during their injection or disconnection into/from the power system. In addition, the high harmonic distortion in the output voltage and current waveforms may also be observed due to the excessive inverter switching frequencies used for controlling distributed generator’s (DG) power output. Hence, the development of a robust and intelligent controller for the grid-connected microgrid (MG) is the need of the hour. As such, this paper aims to develop a robust and intelligent optimal power flow controller using a grasshopper optimization algorithm (GOA) to optimize the dynamic response and power quality of the grid-connected MG while sharing the desired amount of power with the grid. To validate the effectiveness of proposed GOA-based controller, its performance in achieving the desired power sharing ratio with optimal dynamic response and power quality is compared with that of its precedent particle swarm optimization (PSO)-based controller under MG injection and abrupt load change conditions. The proposed controller provides tremendous system’s dynamic response with minimum current harmonic distortion even at higher DG penetration levels.
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Tomczuk, K., P. Mazurek, L. Hemka, A. Kasprowicz, and T. Błażejczyk. "Investigation of HID-lamp light emission differences for different power supply methods." Bulletin of the Polish Academy of Sciences Technical Sciences 64, no. 4 (December 1, 2016): 915–23. http://dx.doi.org/10.1515/bpasts-2016-0100.
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Abstract This paper presents investigation of methods for reducing light pulsation and plasma temperature inside a high intensity discharge (HID) lamp arc tube. Differences found in light emission of an arc tube plasma channel under different power supply methods are presented and discussed in this work. The novelty of the paper lies in systematical investigation of different power converter supply methods and demonstrating that it has a significant influence on plasma temperature in an arc tube. The tested lamp was powered by electronic ballasts controlled by different algorithms, which forced their current waveform. To compare the results, the authors performed measurements on a discharge lamp powered by a standard electromagnetic ballast. The investigation of plasma parameters is based on the optical spectroscopy method. It was shown that by using the appropriate current shape of a high switching frequency supply converter, the plasma temperature of an HID lamp can be reduced almost by half.
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Yi, Chongyin, Bo Yang, Tao Jin, and Shuna Yang. "Photonic Generation and Switching of Multi-Format Chirp Waveforms With Anti-Dispersion Transmission." IEEE Photonics Technology Letters 34, no. 2 (January 15, 2022): 137–40. http://dx.doi.org/10.1109/lpt.2021.3133881.
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Xie, Shijun, Yu Zhang, Huaiyuan Yang, Hao Yu, Zhou Mu, Chenmeng Zhang, Shupin Cao, Xiaoqing Chang, and Ruorong Hua. "Application of Integrated Optical Electric-Field Sensor on the Measurements of Transient Voltages in AC High-Voltage Power Grids." Applied Sciences 9, no. 9 (May 13, 2019): 1951. http://dx.doi.org/10.3390/app9091951.
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Transient voltages in the power grid are the key for the fault analysis of a power grid, optimized insulation design, and the standardization of the high-voltage testing method. The traditional measuring equipment, based on electrical engineering, normally has a limited bandwidth and response speed, which are also featured by a huge size and heavy weight. In this paper, an integrated optical electric-field sensor based on the Pockels effect was developed and applied to measure the transient voltages on the high-voltage conductors in a non-contact measuring mode. The measuring system has a response speed faster than 6 ns and a wide bandwidth ranging from 5 Hz to 100 MHz. Moreover, the sensors have the dimensions of 18 mm by 18 mm by 48 mm and a light weight of dozens of grams. The measuring systems were employed to monitor the lightning transient voltages on a 220 kV overhead transmission line. The switching transient voltages were also measured by the measuring system during the commissioning of the 500 kV middle Tibet power grid. In 2017, 307 lightning transient voltages caused by induction stroke were recorded. The characteristics of these voltage waveforms are different from the standard lightning impulse voltage proposed by IEC standards. Three types of typical switching transient voltage in 500 kV AC power grid were measured, and the peak values of these overvoltages can reach 1.73 times rated voltage.
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Raviola, Erica, and Franco Fiori. "Investigations on the Use of the Power Transistor Source Inductance to Mitigate the Electromagnetic Emission of Switching Power Circuits." Signals 2, no. 3 (September 6, 2021): 586–603. http://dx.doi.org/10.3390/signals2030036.
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With power designers always demanding for faster power switches, electromagnetic interference has become an issue of primary concern. As known, the commutation of power transistors is the main cause of the electromagnetic noise, which can be worsened by the presence of unwanted oscillations superimposed onto the switching waveforms. This work proposes a solution to mitigate the oscillations caused by the turn-on of a power transistor by exploiting its source inductance plus an external one. In this context, an optimization method is proposed to find the optimal value of the source inductance as a trade-off between oscillation damping and power dissipation. The experimental results performed on a prototyped power converter assess the proposed technique as the spectrum of the conducted emission is attenuated by 20 dB at the oscillation frequency. With respect to traditional solution based on snubbers, the proposed solution results in a similar oscillation damping, but with a 0.5% higher power efficiency.
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Zhao, Zhennan, Shanlu Zhang, Lei Li, Shengfang Fan, and Cheng Wang. "Digital Implementation of LCC Resonant Converters for X-ray Generator with Optimal Trajectory Startup Control." World Electric Vehicle Journal 13, no. 5 (April 19, 2022): 71. http://dx.doi.org/10.3390/wevj13050071.
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High voltage LCC resonant converters have been widely used in X-ray imaging systems in automobile nondestructive testing (NDT) applications. Low ripple voltage waveforms with fast-rising time under no-overshoot response are required for safety in such applications. The optimal state trajectory control (OTC) based on the state plane model is one of the most effective control methods to optimize transient response. Dynamic variations of the resonant voltages/currents are described as corresponding trajectories on the state plane. The transient relations can be determined by evaluating the geometric relationships of the trajectories. However, the LCC resonant converter has more state variables, resulting in more complex calculations that make the state trajectory control challenging. Furthermore, the startup duration is the most demanding process of the state trajectory control. In this paper, a digital implementation based on a hybrid controller built in a field-programmable gate array (FPGA) is proposed for LCC resonant converters with optimal trajectory startup control. A coordinated linear compensator is employed to control the switching frequency during steady-state conditions, hence eliminating the steady-state error. The experimental results were conducted on a 140-kV/42-kW LCC resonant converter for an X-ray generator. It achieves a short rising time of output voltage with no additional current or voltage stress in the resonant tank during startup compared to the conventional digital implementation control.
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Popović, I., and M. Zlatanović. "Equivalent Circuits of Unipolar Pulsed Plasma System for Electrical and Optical Signal Analysis." Materials Science Forum 555 (September 2007): 89–94. http://dx.doi.org/10.4028/www.scientific.net/msf.555.89.
Full textAbstract:
Matching of pulse plasma generators to various gas discharges for surface treatment of materials depends on plasma processing equipment. In order to investigate the influence of pulse plasma generator and gas discharge parameters on electrical signal waveforms during the process of unipolar pulse plasma nitriding, equivalent electrical circuit was introduced. The influence of parasitic inductance of interconnection lines and vacuum chamber physical properties was also included in the given equivalent circuit. Gas discharge characteristics at different process parameters were investigated. It was found that the gas discharge and pulse plasma generator properties, as well as the electrical characteristics of interconnecting lines determined the system electrical signal response. From the analysis of optical signals emitted by the gas discharge it was found that the optical signal response might be represented by a typical RC integrator circuit response with the time constant higher than that of the equivalent electrical circuit of generator load. The conclusion was drawn that the process of charge particles generation is followed by the process of active species generation responsible for thermo-chemical processes on the cathode surface. Thus, the increase of the pulse plasma frequency is limited by the thermo-chemical process efficiency, and not only by the generator switching characteristics or by gas discharge electrical properties.
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Roy, Abeera D., and Chandrahasan Umayal. "Performance Analysis of a Half Bridge Cell Based Asymmetrical Multilevel Inverter Topology with Minimum Components." Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 13, no. 4 (July 5, 2020): 531–45. http://dx.doi.org/10.2174/2352096512666190417122807.
Full textAbstract:
Background: In Multilevel Inverters (MLI) as the number of level increases, there is a proportionate increase in the count of the semiconductor devices that are employed. Methods: This paper deals with an asymmetrical cascaded H-bridge inverter topology with half bridge cells to produce seven level output voltage waveform. Nearest Level Control (NLM) technique is used to produce the switching pulses. The operating principle of the proposed MLI and its performance abilities is verified through MATLAB/Simulink and a prototype is developed to provide the experimental results. Results: Total Harmonic Distortion (THD) is computed for proposed MLI for different types of loads in simulation environment as well as in the developed hardware prototype. Comparison between the proposed MLI and recent topologies demonstrates the advantageous features. Conclusion: The simulation and hardware results confirm the suitability of the proposed seven level MLI as the total component count, and the requirement of DC sources reduces considerably.