Journal articles: 'Medium Voltage measurement'

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Wetula, Andrzej, Andrzej Bień, and Mrunal Parekh. "New Sensor for Medium- and High-Voltage Measurement." Energies 14, no. 15 (July 31, 2021): 4654. http://dx.doi.org/10.3390/en14154654.

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Measurements of medium and high voltages in a power grid are normally performed with large and bulky voltage transformers or capacitive dividers. Besides installation problems, these devices operate in a relatively narrow frequency band, which limits their usability in modern systems that are saturated with power electronic devices. A sensor that can be installed directly on a wire and can operate without a galvanic connection to the ground may be used as an alternative voltage measurement device. This type of voltage sensor can complement current sensors installed on a wire, forming a complete power acquisition system. This paper presents such a sensor. Our sensor is built using two dielectric elements with different permeability coefficients. A finite element method simulation is used to estimate the parameters of a constructed sensor. Besides simulations, a laboratory model of a sensor was built and tested in a medium-voltage substation. Our results provide a proof of concept for the presented sensor. Some errors in voltage reconstruction have been traced to an oversimplified data acquisition and transmission system, which has to be improved during the further development of the sensor.

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Crotti, Gabriella, and Domenico Giordano. "Set up and characterization of a measuring system for PQ measurements in a MV site with PV generation." ACTA IMEKO 4, no. 1 (February 5, 2015): 97. http://dx.doi.org/10.21014/acta_imeko.v4i1.171.

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The features of a Power Quality measurement system which includes both voltage and current transducers and a self-developed measuring instrument are described. The system is intended for measurements in substations at medium voltage level. A Rogowski coil and a voltage divider are the used transducers, whereas the measuring instrument is based on a Reconfigurable I/O-FPGA system with embedded software. Attention is focused on the procedures adopted for the characterization of the voltage and current sensors, which are carried out taking into account the expected on-site measurement conditions. An example of use of the systems for measurement of some PQ parameters in a private substation which connects an industrial load and two photo-voltaic generation plants to the public MV voltage network is presented, together with the associated voltage and current uncertainty budget. By making use of the results obtained in the characterization phase, the current and voltage measurement uncertainty can be reduced.

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Kozyra, Jacek. "An analysis of remote voltage measurement in the medium voltage cable networks." PRZEGLĄD ELEKTROTECHNICZNY 1, no. 10 (October 3, 2022): 301–8. http://dx.doi.org/10.15199/48.2022.10.67.

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Artale, Giovanni, Antonio Cataliotti, Valentina Cosentino, Dario Di Cara, Salvatore Guaiana, Enrico Telaretti, Nicola Panzavecchia, and Giovanni Tinè. "Incremental Heuristic Approach for Meter Placement in Radial Distribution Systems." Energies 12, no. 20 (October 16, 2019): 3917. http://dx.doi.org/10.3390/en12203917.

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The evolution of modern power distribution systems into smart grids requires the development of dedicated state estimation (SE) algorithms for real-time identification of the overall system state variables. This paper proposes a strategy to evaluate the minimum number and best position of power injection meters in radial distribution systems for SE purposes. Measurement points are identified with the aim of reducing uncertainty in branch power flow estimations. An incremental heuristic meter placement (IHMP) approach is proposed to select the locations and total number of power measurements. The meter placement procedure was implemented for a backward/forward load flow algorithm proposed by the authors, which allows the evaluation of medium-voltage power flows starting from low-voltage load measurements. This allows the reduction of the overall costs of measurement equipment and setup. The IHMP method was tested in the real 25-bus medium-voltage (MV) radial distribution network of the Island of Ustica (Mediterranean Sea). The proposed method is useful both for finding the best measurement configuration in a new distribution network and also for implementing an incremental enhancement of an existing measurement configuration, reaching a good tradeoff between instrumentation costs and measurement uncertainty.

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Petkovic, Marko, Nicolai Hildebrandt, Francisco D. Freijedo, and Drazen Dujic. "Medium Voltage Impedance-Admittance Measurement System Based on the Cascaded H-Bridge Multilevel Converter." Electronics ETF 22, no. 2 (September 19, 2019): 105. http://dx.doi.org/10.7251/els1822105p.

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Recent trends in power system design such as an increasing share of renewable energy sources and smart grids are creating different subsystem interactions that require proper investigation, understanding, describing and estimating global system stability through impedance-admittance measurement and identification. This paper proposes and presents the cascaded H-bridge multilevel inverter topology for perturbation injection converter and impedance-admittance measurement. The methodology of impedance-admittance measurement is explained together with different measurements requirements. Performance and suitability of this topology for impedance-admittance measurement is evaluated through simulations. Preliminary design principles are given for the converter. System level feasibility of the solution is proposed as a main result of the work.

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Mingotti, Alessandro, Christian Betti, Lorenzo Peretto, and Roberto Tinarelli. "Simplified and Low-Cost Characterization of Medium-Voltage Low-Power Voltage Transformers in the Power Quality Frequency Range." Sensors 22, no. 6 (March 15, 2022): 2274. http://dx.doi.org/10.3390/s22062274.

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The distribution network is experiencing a massive deployment of intelligent electronic devices (IEDs) such as energy meters, protective devices, and phasor measurement units (PMUs). This phenomenon resulted, on the one hand, in (i) the availability of distributed measurement systems capable of monitoring and collecting measurements from the distribution network, and (ii) increasing awareness of the system operator about the status of the network. On the other hand, such a significant number of devices require to be characterized, over the years, and assessed in both sinusoidal and distorted conditions. However, the characterization process may require a huge investment of money and time considering the low availability of reference instruments and accredited laboratories. To this purpose, this paper presents a simple and fast test procedure, performed with cheap and low-voltage instrumentation, to characterize two off-the-shelf low-power medium-voltage sensors in the power quality frequency range. In detail, the paper describes the measurement setup developed for the characterization and the performed tests. In addition, the method was also reproduced with reference equipment for validation purposes. Lastly, for both tests, an uncertainty evaluation was performed to quantify the goodness of the proposed method. From the results, it is possible to appreciate that the designed cheap and simple test can achieve as accurate results as those of a sophisticated and expensive equipment.

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Paulo Vogel, Ederson, and Cesar David Paredes Crovato. "Study of Non-Contact and Non-Ground Voltage Signal Measurement System in Medium Voltage." IEEE Latin America Transactions 16, no. 2 (February 2018): 416–21. http://dx.doi.org/10.1109/tla.2018.8327394.

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Cataliotti, Antonio, Valentina Cosentino, Dario Di Cara, and Giovanni Tine. "Measurement Issues for the Characterization of Medium Voltage Grids Communications." IEEE Transactions on Instrumentation and Measurement 62, no. 8 (August 2013): 2185–96. http://dx.doi.org/10.1109/tim.2013.2264861.

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Gayatri Citra Dewi and Odetta Levin. "Analysis of Nickel(II) in Water Medium using Electrochemical Techniques." Chemistry and Materials 2, no. 1 (February 28, 2023): 24–29. http://dx.doi.org/10.56425/cma.v2i1.49.

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Nickel (Ni) is a highly toxic heavy metal because nickel can accumulate and poison aquatic biotic components, therefore it’s levels must be determined with certainty. In this study, nickel metal measurements were made using the cyclic voltammetry method. Several measurement parameters, including voltage range, scan rate, and pH, were tested in this study to improve sensitivity and accuracy. This is done to achieve the best possible measurement conditions. The results show that the best conditions for detecting Ni ions are a voltage range of -0.75 V to -1.00 V, a scan rate of 250 mV/s, and a pH of 3. The validation test produced results in the range of 15 to 40 mM with a correlation coefficient of 0.99, detection and quantitation limits of 274.99 ppm and 916.66 ppm, respectively, and an RSD of 1.10%. As a comparison, Ni content was tested using AAS, and the Ni contents obtained by cyclic voltammetry and AAS methods were 1666.47 and 1676 ppm, respectively.

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Čeović, Josip, and Matko Širola. "Medium and Low Voltage Cable Measurements - TD, PD, LIRA." Journal of Energy - Energija 65, no. 1-2 (June 27, 2022): 24–37. http://dx.doi.org/10.37798/2016651-2125.

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Elmont d.o.o. Krško – We have spread our main scope of the services from electrical maintenance, modifications implementations and quality control to cable testing area. The main reason for expanding our scope was to support Nuclear Power Plant Krško Cable Aging Management program and the world trend of LTE (Life Time Extension) in power plants. Scope of work – We are identifying potential downgraded conditions for safety and operational important cables in special areas (heat, water, radiation). Our main scope is visual control, and testing with analysis. For low voltage cables the main testing method is Line Resonance Analysis (LIRA). LIRA technology is based on the transmission line theory, through the estimation and analysis of the complex line impedance as a function of the applied signal frequency. We can monitor the global, progressive degradation of the cable insulation due to harsh environment conditions (high temperature, humidity, radiation) and detect local degradation of the insulation material due to mechanical impacts or local abnormal environmental conditions. For medium voltage cables we are using new methods with a power generator that uses Very Low Frequency – 0,1Hz (VLF). The main reason for this is that the measurement unit needs 500 times less energy than the unit which uses 50Hz frequency (50/0,1=500). With this power source we are performing dielectric loss measurements – Tan delta (TD) and Partial discharge measurements (PD). TD measurements show the severity of Water treeing in the measured cable. Water trees mainly come from moisture and are therefore present in cables that lie in manholes filled with water or they submerged in any other way. PD measurements show the severity of voids or other types of defects in cable insulation. These defects can arise during the manufacturing of the cable or they can arise during the installation of the cable or from an accident with the cable during the operational time.

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Touhami, Maroua O., Emir Sokić, Amer Smajkić, Andres Laso, and Nenad Uzelac. "Data Acquisition and Simulation Software as Tools for Medium Voltage Switchgear Assessment and Optimization." B&H Electrical Engineering 15, no. 1 (October 1, 2021): 89–97. http://dx.doi.org/10.2478/bhee-2021-0011.

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Abstract This paper describes the advantages of using data acquisition systems and software modelling tools to support the assessment and therefore redesign of the existing medium voltage switchgear. A 38kV/630A load break linear puffer (LP) will be used as an example for this study. In house testing was conducted to capture important design parameters of the switch such as displacement, velocity of mechanical parts and gas pressure using various sensors and three different measurement setups. The first setup, which is primarily intended for no-load measurements, consists of a DAQ system equipped with different types of sensors - two rotational encoders, three laser-based distance sensors, six pressure sensors, contact separation measurement, and a high-speed camera integrated and synchronized with the measurement system. The second and third setups, which are suitable both for no-load and on-load measurements, are based on state-of-the-art DAQ systems, which use three piezo-electric based pressure sensors, two fibre-optic based pressure sensors, three laser-based distance sensors and a high speed camera synchronized with the measurement system. The data acquired by the measurement systems is used in combination with an in-house developed simulation software HV CB Simulation, which enables simulating and predicting various variables of switching devices. Moreover, high speed camera videos analysed with both commercial and in-house developed image processing software, visualize and reveal many otherwise inaccessible occurrences. In addition to a comprehensive analysis of the proposed data acquisition and simulation setups, three design improvements in the linear puffer design - increase of the opening speed, removal of the flexible conductors and the length increase of the puffer cylinder - are presented and discussed in this paper.

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Wang, Chau-Shing, Wen-Ren Yang, and Yi-Cheng Hsu. "Enhancement of the Flickermeter for Grid-Connected Wind Turbines." Energies 14, no. 18 (September 13, 2021): 5734. http://dx.doi.org/10.3390/en14185734.

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Distributed generators connected to the power system usually produce voltage fluctuations. For wind turbines connected to a grid, large changes in wind speed can cause voltage flicker at the point of common coupling. The measurement of voltage flicker caused only by wind turbines is difficult. The wind turbine under test is usually connected to a medium voltage point, in which other fluctuating loads may produce significant voltage disturbances at the wind turbine terminal where the measurement is made. Although the IEC 61400-21-1 standard specifies a method to evaluate voltage flicker caused by wind turbines, because of the complex algorithm and process of the IEC standard, there is currently a lack of measurement equipment that meets the IEC standard. In addition, some countries that use other voltage flicker standards, such as ΔV10, do not have suitable flicker measurements for wind turbines. Therefore, this study proposes an enhanced version of the IEC 61400-21-1 standard, which integrates the ΔV10 method, so that the proposed measurement system complies with the IEC and ΔV10 standards. In this study, the voltage flicker measurement system is successfully implemented, which can help engineers to predict the voltage flicker by wind turbines and assess whether a region or grid is suitable for installing wind turbines. Therefore, it can provide wind turbine companies with a quick assessment of voltage flicker to comply with the certification process.

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Xie, Yue, and Jing Chen. "Research on the Calibration Instrument for the Medium-Voltage Electronic Instrument Transformers." Advanced Materials Research 433-440 (January 2012): 7471–78. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.7471.

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Electronic instrument transformers are used in power line for electrical measurement and protection purposes. Calibration instruments are necessary for the transformation error test of electronic instrument transformers. The operation principles of the direct and difference measurement method based calibration instrument for the medium-voltage electronic instrument transformers are systematically analyzed in this paper. The analysis results show that the direct measurement method based instrument can be used for the calibration of electronic instrument transformers with air-core coils or resistor-capacitor voltage divider without a built-in integrator, and the difference measurement method based instrument is suitable for the calibration of the electronic instrument transformers with no rated phase offset.

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Mingotti, Alessandro, Lorenzo Peretto, and Roberto Tinarelli. "Low-Impact Current-Based Distributed Monitoring System for Medium Voltage Networks." Energies 14, no. 17 (August 26, 2021): 5308. http://dx.doi.org/10.3390/en14175308.

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Distribution networks are currently subject to a huge revolution in terms of assets being installed. In particular, the massive spread of renewable energy sources has drastically changed the way of approaching the grid. For example, renewables affected (i) the production of the legacy power plants, (ii) the quality of the supplied energy, decreasing it, (iii) the fault detection and location, etc. To mitigate the significant drawbacks of the renewables’ presence, several intelligent electronic devices have been (and are being) developed and installed among the grid. The aim is to increase grid monitoring and knowledge of its status. However, considering the significant number of nodes of the distribution network, compared to the transmission one, the process of installing new equipment is not effortless and is also quite expensive. This work aims at emphasizing a new concept of distributed monitoring systems, based on the phasor measurement unit’s current measurements, and a controlling algorithm to exploit it. The idea underneath the work is to avoid the out-of-service time needed and the costs associated with the installation of voltage sensors. Therefore, this paper describes an algorithm that exploits measurements from existing equipment and current measurements from PMUs to obtain information on the load and the node voltages. The algorithm is then tested on simulated power networks of increasing complexity and verified with an uncertainty evaluation. The results obtained from the simulation confirm the applicability and effectiveness of the algorithm and the benefits of a current-based monitoring system.

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Cselkó, Richárd. "Repetition Rate of Partial Discharges in Low Voltage Cables." Periodica Polytechnica Electrical Engineering and Computer Science 64, no. 1 (October 30, 2019): 33–39. http://dx.doi.org/10.3311/ppee.14434.

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Diagnostic testing of low voltage cables by partial discharge measurement has several difficulties. One of them is that the cables are not designed to be partial discharge free at their test voltage. As partial discharge impulses may originate from numerous spots even in new cables, it is expected that impulses reach the termination with high repetition rate. The propagation of impulses in low voltage cables differs from the medium and high voltage cables; there is no lossy semiconducting layer or layers, but the cross section of the conductors are lower. The measurement method of partial discharges has to be adjusted to the discharge type and the propagation path as these determine the frequency content of the individual impulses, and the time resolution of the system has to be appropriate for the expected repetition rate. Measurements have been performed on various types of cables by different methods. Based on the results suggestions are given on the suitable measurement methods.

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Abdullah, A. Z., M. Isa, M. N. K. H. Rohani, H. A. Hamid, M. H. Amlus, and N. Azizan. "Modelling and simulation of online partial discharge measurement for medium voltage power cable." Bulletin of Electrical Engineering and Informatics 9, no. 2 (April 1, 2020): 427–35. http://dx.doi.org/10.11591/eei.v9i2.2076.

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This paper presents the modelling of the online partial discharge (PD) measurement of the medium voltage (MV) power cable. Recently, PD monitoring trends are rapidly increasing due to high demand on reliable systems. Degradation are mainly due to the presence of PD in the high voltage power equipment used. PD measurement is therefore a highly recommended task to early detection of the degradation insulation for high voltage (HV) equipment in order to avoid breakdowns. Real network modelling is necessary to improvise system design in order to find the efficiency in a real power system network. In this paper, modelling focuses on a real distribution network by applying Rogowski coil (RC) as a detection sensor to trigger PD activity. The simulation is performed to determine the functionality and reliability of the system with the RC application in the network. The analysis is performed in the ATP-EMTP and MATLAB Simulink software environments. In addition, this paper contributed to justify the approach of a simplified PD sensor and measurement system. This PD measurement system provides a complete solution in the context of condition-oriented monitoring for the ability to apply the RC to trigger PD activity in the power distribution network.

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Artale, Giovanni, Giuseppe Caravello, Antonio Cataliotti, Valentina Cosentino, Dario Di Cara, Salvatore Guaiana, Ninh Nguyen Quang, Marco Palmeri, Nicola Panzavecchia, and Giovanni Tinè. "A Virtual Tool for Load Flow Analysis in a Micro-Grid." Energies 13, no. 12 (June 18, 2020): 3173. http://dx.doi.org/10.3390/en13123173.

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This paper proposes a virtual tool for load flow analysis in energy distribution systems of micro-grids. The solution is based on a low-cost measurement architecture, which entails low-voltage power measurements in each secondary substation and a voltage measurement at the beginning of the medium voltage (MV) feeder. The proposed virtual tool periodically queries these instruments to acquire the measurements. Then, it implements a backward–forward load flow algorithm, to evaluate the power flow in each branch and the voltage at each node. The virtual tool performances are validated using power measurements acquired at the beginning of each MV feeder. The uncertainties on each calculated quantity are also evaluated starting from the uncertainties due to the used measurement instruments. Moreover, the influence of the line parameter uncertainties on the evaluated quantities is also considered. The validated tool is useful for the online analysis of power flows and also for planning purposes, as it allows verifying the influence of future distributed generator power injection. In fact, the tool is able to off-line perform the load flow calculation in differently distributed generation scenarios. The micro-grid of Favignana Island was used as a case study to test the developed virtual tool.

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Lesniewska, Elzbieta. "Modern Methods of Construction Problem Solving in Designing Various Types of Instrument Transformers." Energies 15, no. 21 (November 3, 2022): 8199. http://dx.doi.org/10.3390/en15218199.

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Current and voltage instrument transformers are essential elements of the power system. They work like transformers but do not transmit power. Their task is to accurately transform currents or voltages during system operation, which are then used for measurement and protection. These devices are very precise, and their accuracy is defined by the IEC/CEN standards. Instrument transformers are located at all transformer stations, specialized high-voltage and high-power laboratories, and testing and teaching laboratories. Therefore, the design requirements are very different depending on their type (current, voltage, or combined), function (measuring, protection), and operating voltage (high, medium, and low). The requirements concern not only the operation but also the strength of the insulation system and, sometimes, the mechanical strength.

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Marat-Mendes, José N., Eugen R. Neagu, and Rodica M. Neagu. "Electric Charge Trapping and Transport at Medium Fields in Low-Density Polyethylene." Materials Science Forum 480-481 (March 2005): 495–500. http://dx.doi.org/10.4028/www.scientific.net/msf.480-481.495.

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The transient conductivity in low-density polyethylene is studied. Isochronal currentvoltage measurements for 1800 s and 1 day time intervals are carried out under dry N2 atmosphere. When after every measurement the sample is fully discharged at high temperature the isochronal current - voltage characteristic reveals an ohmic behavior. When the next field increase is applied without sample discharging the current-voltage characteristic is super-quadratic. We explain this increase of the current assuming that a fraction of the previous injected charge is detrapped by the field and it contributes to current increase. Consequently the current – voltage characteristic is strongly dependent on the time lag between two successive rises in the field. Neither the Poole-Frenkel mechanism nor the Richardson – Schottky mechanism can by used to explain the experimental results. The isothermal charging and discharging currents are explained assuming the movement of injected/ejected charge in the resultant local field. The values obtained for the adjustable parameters of the model are in good agreement with the values in the literature.

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Vitor, Ulysses R. C., Matheus Cabral, Daniel Fonseca, Lauro R. G. S. L. Novo, Marcos T. de Melo, Marcelo E. V. Segatto, and Gabriel G. Machado. "MIMO-PLC Communications in an Experimental Medium Voltage Network: Measurement and Analysis." Journal of Microwaves, Optoelectronics and Electromagnetic Applications 21, no. 1 (March 2022): 102–13. http://dx.doi.org/10.1590/2179-10742022v21i11380.

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Xiaoxian, Yang, Zheng Tao, Zhang Baohui, Huang Zonghong, Chen Jian, and Gui Zhiqiang. "Channel Model and Measurement Methods for 10-kV Medium-Voltage Power Lines." IEEE Transactions on Power Delivery 22, no. 1 (January 2007): 129–34. http://dx.doi.org/10.1109/tpwrd.2006.876697.

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Mosland, Eivind N., Jan Kocbach, and Per Lunde. "Errors using the spatially averaged free-field pressure approximation for description of the receiving properties of piezoelectric transducers." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A227. http://dx.doi.org/10.1121/10.0016092.

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In modelling of ultrasonic measurement systems and calculation of diffraction corrections for such systems, it is often assumed that the spatially averaged free-field pressure over the front surface of a piezoelectric transducer, ⟨ p⟩, can be used to calculate its voltage output. It is of interest to investigate whether errors due to this ⟨ p⟩-approximation are acceptable for piezoelectric transducers applied in high-precision ultrasonic measurements in fluids. 3D-axisymmetric finite element (FE) modelling is used to investigate such errors in a transmit-receive measurement setup employing two identical transducers. The approximate output voltage is found by Vout = ⟨ p⟩ MV and compared to the output voltage from FE modelling of the transmitter-medium-receiver system, Vout,ref , using the appropriate boundary conditions at the two transducers. MV is the open-circuit free-field receiving voltage sensitivity of the receiver for normally incident plane wavefronts, calculated assuming spherical reciprocity. Two examples of piezoelectric transducer pairs are studied, operated in the frequency range of their lower radial modes. It is shown that the ⟨ p⟩-approximation may introduce notable deviations between V out and Vout,ref , of up to approximately 40° for the phase angle and 2 dB for the magnitude. The deviations depend on the fluid medium, separation distance, frequency, and the transducer’s construction and vibrational characteristics.

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Ana, Ricardo Santa, Marvin Muchametow, and Manjunath Ramesh. "New Method of Leak Rate Measurement in SF₆ Free Medium Voltage Switchgear Using Helium and Ambient Air." B&H Electrical Engineering 15, no. 1 (October 1, 2021): 54–62. http://dx.doi.org/10.2478/bhee-2021-0006.

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Abstract The current medium voltage Gas Insulated Switchgears (GIS) predominantly use Sulphur Hexafluoride (SF6) as insulation medium. The leakage tests performed on GIS use either SF6 or Helium medium to ensure gas tightness. However, SF6 has been strictly regulated for the last years due to the high global warming potential effect on the planet. As a response, new technologies are emerging using air as insulation medium. The present work establishes a basic comparison of the leakage rate in a medium voltage GIS using two different leak detection methods: Helium leak detector and Residual Gas Analyser (RGA). Both methods use Helium and additionally RGA using air as tracer gas.

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Nie, Yu, Guoqing Zhang, Jiakuo Song, and Guizhong Wang. "Simulation and Experimental Research on Overvoltage Measurement of Hybrid CVT." E3S Web of Conferences 256 (2021): 01016. http://dx.doi.org/10.1051/e3sconf/202125601016.

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The CVT equipment running on site is slightly modified to form a hybrid CVT to achieve transient overvoltage measurement, which is theoretically feasible and practical. In order to study the voltage division method based on the hybrid CVT to measure the overvoltage of the power system, that is, the low voltage capacitor C3 is connected in series between the low voltage terminal of the medium voltage capacitor C2 of the traditional CVT and the ground, and the transient overvoltage measurement is realized through C3. This article uses ATP-EMTP to establish its high-frequency transient model for simulation analysis. For further verification, a power frequency voltage test and an impulse voltage test were carried out on the 110kV hybrid CVT produced by Taikai Transformer Factory, focusing on the analysis of the partial voltage characteristics of the capacitor C3. The simulation results show that the C3 partial pressure method can achieve a relatively accurate measurement of the transient overvoltage. The test results show that the voltage across C3 is affected by uncertain factors and has an impact phenomenon. The above analysis process and results have certain practical value for designing actual products.

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Mingotti, Alessandro, Federica Costa, Lorenzo Peretto, and Roberto Tinarelli. "Characterization Procedure for Stand-Alone Merging Units Based on Hardware-in-the-Loop Technology." Energies 14, no. 7 (April 4, 2021): 1993. http://dx.doi.org/10.3390/en14071993.

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The digitalization of a medium voltage network requires huge efforts from distributed system operators and electric utilities. The main reason is attributed to the costs associated with the replacement or introduction of new intelligent electronic devices capable of collecting and digitalizing current and voltage measurements. To this purpose, this paper introduces a new idea of a stand-alone merging unit (SAMU), which features real-time and hardware-in-the-loop technology, completed with accurate voltage and current sensors. Furthermore, the characterization procedure that allows an evaluation of the metrological performance of a complex device, such as a SAMU, is fully described. From the results, it is highlighted that (i) the developed SAMU is capable of performing highly accurate voltage, current, and power measurements; (ii) the characterization procedure is simple and exploitable for all kinds of SAMUs and other synchronized measurement devices.

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Kryltcov, Sergei, Aleksei Makhovikov, and Mariia Korobitcyna. "Novel Approach to Collect and Process Power Quality Data in Medium-Voltage Distribution Grids." Symmetry 13, no. 3 (March 12, 2021): 460. http://dx.doi.org/10.3390/sym13030460.

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The paper is devoted to the development of the structure of a fast and flexible data collecting system based on the proposed approach to measure power quality indicators in three-phase medium-voltage distribution grids with an example of a Mikhailovsky mining and processing plant. The approach utilizes the properties of a space vector, obtained from grid currents and voltages with disturbed waveform, to allow faster extraction of the harmonic components compared to traditional approaches, based on the direct Fourier-transform applied to a line or phase values. During the study, the concept of a universal measurement device was introduced, which allows fast estimation of the following values at the grid node: magnitudes and phases of voltage and current harmonic components, active and reactive power of harmonics and fundamental components, positive and negative instantaneous powers. The structure of interconnected measurement and control units for the considered grid node with simultaneous operation of two active variable frequency drives with active rectifiers was proposed in accordance with a concept of the Internet of things. The benefits of the proposed solution are shown by the example of the model of the grid node with two operating draglines and nonlinear load, which was developed in MATLAB/Simulink software. The proposed approach was utilized to produce distributed references for control systems of grid inverters to compensate nonlinear currents, which allowed to significantly improve THDi of the grid node input power.

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Brahmana, Kurnia. "The Design of Data Collector to Calculate the Efficiency of DC to AC Inverter Based on ATmega328 and Micro SD as Storage Media." Journal of Technomaterials Physics 2, no. 2 (August 27, 2020): 129–38. http://dx.doi.org/10.32734/jotp.v2i2.5405.

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The data collector to calculate the efficiency of the pure sine inverter DC to AC based on the level of efficiency, voltage and current stored automatically in Micro SD has been successfully designed. This data collector is built from the Arduino Nano (ATmega328) module as the controller and uses a Micro SD Card as a storage medium. The equipment storage results are displayed in real time using the RTC and LCD as a display medium for the measurement results of the voltage sensor and current sensor. The data logger is designed to be useful for storing data from the measurement results of the DC to AC inverter which consists of voltage, current and data collection time. The data every 16 seconds will be stored automatically on the Micro SD. The results of the reading error of the voltage sensor and current sensor are 1.088% and 1.72%, respectively. The results of the error reading the voltage sensor and current sensor are still precise, so the efficiency obtained in this study is 78.37%.

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Zhou, Kai, Qing Xiong, Min He, Lingjiang Dong, and Yalin Chen. "An On-line Monitoring System for Over-voltages Based on a Two-stage Voltage Divider and Field Measurement Results in Medium-voltage Grids." Electric Power Components and Systems 44, no. 12 (June 9, 2016): 1345–56. http://dx.doi.org/10.1080/15325008.2015.1028117.

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Kostić, Vojin. "A contribution to the rationalization of grounding impedance measurement in medium voltage substations." Tehnika 74, no. 1 (2019): 97–102. http://dx.doi.org/10.5937/tehnika1901097k.

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McDermit, Daniel C., David D. Shipp, Thomas J. Dionise, and Visuth Lorch. "Medium-Voltage Switching Transient-Induced Potential Transformer Failures: Prediction, Measurement, and Practical Solutions." IEEE Transactions on Industry Applications 49, no. 4 (July 2013): 1726–37. http://dx.doi.org/10.1109/tia.2013.2258453.

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Jaksic, Marko, Zhiyu Shen, Igor Cvetkovic, Dushan Boroyevich, Rolando Burgos, Christina DiMarino, and Fang Chen. "Medium-Voltage Impedance Measurement Unit for Assessing the System Stability of Electric Ships." IEEE Transactions on Energy Conversion 32, no. 2 (June 2017): 829–41. http://dx.doi.org/10.1109/tec.2017.2692275.

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Domigata, Riga, Tri Bowo Indrato, Triana Rahmawati, and Narongrit Sanajit. "An Improved Power Management System in Electrosurgery Unit Monopolar Design." Indonesian Journal of electronics, electromedical engineering, and medical informatics 2, no. 2 (August 29, 2020): 95–100. http://dx.doi.org/10.35882/ijeeemi.v2i2.6.

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In using the Electrosurgery unit, improper power settings and modes can cause tissue damage, so it is necessary to adjust the cutting mode and power settings needed. The purpose of this research is to design power control and cutting mode in Electrosurgery using Arduino nano as a regulator of power and pulse or duty cycle. The contribution of this research is the creation of power control and mode in the Electrosurgery unit to increase power and cutting mode. This is to control the electrosurgery power. The LM2907 IC frequency to voltage circuit is used as a voltage regulator, which is issued according to the frequency with the power selection LOW, MEDIUM, HIGH. The method used is the CMOS 4069 device as a frequency generator at 250 kHz, then the driver pulse is passed and controlled by the ATmega328 IC, then forwarded to an inverter circuit that functions to increase the voltage and output in the form of power. After the measurement process is carried out on the inverter input with a Blend mode three value, the voltage value is obtained at the low setting 100 V error 0.03%, medium setting 110V error 0.02%, High setting 120 V Error -0.02%. While the measurement results in the coagulation mode are the low setting error of 100 V 0.05%, the medium setting error is 110V 0.08%. High setting error is 130 V 0.003%. The measurements show that the error in power management is lower than 1%. The results of this study can be implemented in the electrosurgery unit to reduce tissue damage due to a lack of cutting modes and power management.

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Shafiq, Muhammad, Guillermo Robles, Amjad Hussain, Kimmo Kauhaniemi, and Matti Lehtonen. "Identifcation and Location of Partial Discharge Defects in Medium Voltage AC Cables." Proceedings of the Nordic Insulation Symposium, no. 26 (August 5, 2019): 22–27. http://dx.doi.org/10.5324/nordis.v0i26.3269.

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The presence of partial discharge (PD) in electricalequipment is the confirmation or indication of an ongoingdegradation of its dielectric insulation. PD study is a widely usedtool for condition monitoring of medium voltage (MV) cables.The location of the defects can be considered as one of the mostimportant tasks of diagnosis in underground installations of MVcables. A lot of references can be found on the location of singlePD sources along the cable. However, several PD defects can beactive simultaneously along a cable section. This paper presentsan experimental study on a MV cable having two PD sourcesand noise. Adopting one end measurement technique, a highfrequency current transformer (HFCT) is used to capture the PDcurrent pulses. A simple approach of identification of the PDsignals originated from different PD sources is presented basedon wave-shape study along with a time domain reflectometryanalysis. The presented measurement methodology and timedomain analysis technique provides a convenient way fordetection and location of more than one PD sources along a cablesection.

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Kong, Xiangyu, Ying Chen, Tao Xu, Chengshan Wang, Chengsi Yong, Peng Li, and Li Yu. "A Hybrid State Estimator Based on SCADA and PMU Measurements for Medium Voltage Distribution System." Applied Sciences 8, no. 9 (September 1, 2018): 1527. http://dx.doi.org/10.3390/app8091527.

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With the increasing importance of renewable energy and flexible loads, the operation of the distribution system is becoming more stochastic and complex, and it is necessary to monitor the power system in real-time. Considering the gradual applications of intelligent electronic devices in the distribution systems, a hybrid state estimator based on supervisory control and data acquisition (SCADA) and phasor measurement unit (PMU) measurements is proposed in this paper, which consists of the improved robust estimation and linear state estimation. At the time of SCADA data acquisition, the improved robust estimation combining the SCADA measurements with PMU measurements is performed. To eliminate the effect of bad data, the internal student residual method is introduced, and the robust thresholds are adjusted adaptively. Then the linear state estimation is performed at the time of PMU data acquisition based on the results of the previous estimation time and the PMU measurements, which can quickly correct the robust estimation results and track the changes of the distribution system. Finally, the effectiveness and performance of the proposed method are verified in a modified IEEE 33-bus distribution system and a real distribution system in China.

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Mingotti, Alessandro, Federica Costa, Gaetano Pasini, Lorenzo Peretto, and Roberto Tinarelli. "Modeling Capacitive Low-Power Voltage Transformer Behavior over Temperature and Frequency." Sensors 21, no. 5 (March 2, 2021): 1719. http://dx.doi.org/10.3390/s21051719.

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The use of capacitive dividers (CDs) in medium-voltage (MV) networks started as simple voltage detectors and as rough voltage measurement instruments for protective purposes. Now, with the spread of intelligent electronic devices and renewable energy sources at the distribution level, capacitive dividers are designed and installed to perform accurate voltage measurements. Such a requirement is mandatory when the power quality has to be assessed. Therefore, CDs are currently being used either for power frequency or for high-frequency (supraharmonic- or partial-discharge-level) measurements. In this paper, typical off-the-shelf CDs are studied and modeled to understand how they behave in a wide range of frequencies and when the temperature varies. To this purpose, specific setups and tests have been developed and performed. From the results, it is clear that with proper modeling of CDs, it is possible to exploit them for measuring phenomena in a wide range of frequencies, including the effects due to temperature variations and self-resonances.

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Kanálik, Martin, Anastázia Margitová, Ľubomír Beňa, and Andrea Kanáliková. "Power System Impedance Estimation Using a Fast Voltage and Current Changes Measurements." Energies 14, no. 1 (December 24, 2020): 63. http://dx.doi.org/10.3390/en14010063.

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Equivalent power system impedance is an important electrical quantity from many points of view. Areas in which this parameter plays an important role include, in particular: Voltage stability analysis, power quality, or fault condition analysis. Power system impedance estimation in real operation conditions can be performed by one of the non-invasive methods described by different authors. This paper aims to investigate and compare seven different methods for power system impedance estimation based on voltage and current variations measurement. After a brief description of selected methods, these methods were applied for power system impedance estimation in the case of two simple simulation tests and then in the case of three real measured data. Voltage and current changes used for power system impedance estimation in real conditions were measured in high voltage (HV) and medium voltage (MV) substations feeding steel mill with the electric arc furnace (EAF) operation. As the results presented in this paper have shown, not all of the methods analyzed are suitable for determining the power system impedance based on the fast step changes of voltage and current that occur, for example, during an EAF operation. Indeed, some of the tested methods were originally designed to determine the power system impedance from changes in voltages and currents recorded at steady state.

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Hussain, Ghulam Amjad, Ashraf A. Zaher, Detlef Hummes, Madia Safdar, and Matti Lehtonen. "Hybrid Sensing of Internal and Surface Partial Discharges in Air-Insulated Medium Voltage Switchgear." Energies 13, no. 7 (April 5, 2020): 1738. http://dx.doi.org/10.3390/en13071738.

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Partial discharge (PD) measurements have proved their reliability for health monitoring of insulation systems in power system components including synchronous generators, power transformers, switchgear and cables etc. Online condition monitoring and pro-active detection of PD faults have been highly demanded over the last two decades. This paper provides results from a research project to develop advanced non-intrusive sensing technologies that are cost effective, reliable and efficient for early detection of PD faults in medium voltage (MV) and high voltage (HV) air-insulated switchgear. Three sensors (high frequency E-field (D-dot) sensor, Rogowski coil and loop antenna) have been developed and tested under various PD faults and their performance were evaluated in comparison with high frequency current transformer (HFCT) which is being used commercially for PD testing and measurement. Among these three sensors, it is shown that D-dot sensor and Rogowski coil are more dependable when it comes to the PD measurements due to their high signal to noise ratio and hence high accuracy. These sensors can be customized according to a specific application and can be connected together with one data acquisition device while developing an online condition monitoring system.

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Klasnic, Ilija, Jasna Dragosavac, and Zoran Lazarevic. "Improved hydrogenerator field winding thermal monitoring." Thermal Science, no. 00 (2023): 36. http://dx.doi.org/10.2298/tsci221212036k.

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A new monitoring method for determination of average hydrogenerator field winding temperature is introduced in order to increase the robustness of the temperature measurement system using the classic U-I method. The classic approach is prone to error due to brush voltage drop, especially when field voltage is low. Developed thermal model is based on field current and cold cooling air temperature measurements, as well on temperatures acquired from digital temperature sensors mounted across the field winding. To monitor the rotor temperature for generators with brushless excitation where field voltage and current measurements are not accessible, a mathematical model was developed to estimate the average field winding temperature based on the existing temperature monitoring of the cooling medium and mounted sensors. Importance of the proposed approach arises from the foreseen widespread use of brushless generators in distributed generation. The developed models were compared and their sensitivity was examined thoroughly.

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Cheng, Yujia, Guang Yu, and Zhuohua Duan. "Effect of Cooling Medium on LDPE Dielectric Properties." Polymers 14, no. 3 (January 21, 2022): 425. http://dx.doi.org/10.3390/polym14030425.

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Polyethylene, with its excellent mechanical and dielectric properties is used as an insulator for high-voltage direct current (HVDC) transmission. In ultra-high-voltage direct current (UHVDC) transmission, the ageing of insulation materials caused by space charge under high DC voltage becomes serious. Therefore, restraining the space charge and improving the dielectric properties of HVDC cables is important. In this study, low-density polyethylene (LDPE) was used as the raw material and combined with cooling media in a vulcanizing press. A polarizing microscope was used to observe the samples’ crystal morphologies. The space charge accumulation and dispersion were detected using pulsed electro-acoustic. Additionally, dielectric properties such as electrical conductivity and dielectric frequency spectrum were tested. The grain size in the air-cooled LDPE samples was found to be large and unevenly dispersed. However, the grain sizes in the water and oil cooling LDPE samples were small. The mean charge density of the oil cooling samples was the lowest. Under a short circuit measurement, more space charges were found in the natural and rapid air cooling samples. The mean charge densities of these two samples were high, with a fast decay rate. With an 8 and 50 kV/mm electric field strength, the oil cooling samples’ conductivity was the highest and lowest, respectively.

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Buys, Johannes L., and Charles T. Gaunt. "Measurement-based load parameter modelling for technical and tariff studies of medium voltage feeders." SAIEE Africa Research Journal 113, no. 2 (June 2022): 64–74. http://dx.doi.org/10.23919/saiee.2022.9785540.

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Faifer, Marco, Roberto Ottoboni, Sergio Toscani, Claudio Cherbaucich, and Paolo Mazza. "Metrological Characterization of a Signal Generator for the Testing of Medium-Voltage Measurement Transducers." IEEE Transactions on Instrumentation and Measurement 64, no. 7 (July 2015): 1837–46. http://dx.doi.org/10.1109/tim.2014.2376113.

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Huang, Nan Tian, Xiao Sheng Liu, and Dian Guo Xu. "Review of Channel Characterization for Power Line Communications." Advanced Materials Research 108-111 (May 2010): 771–76. http://dx.doi.org/10.4028/www.scientific.net/amr.108-111.771.

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The power line communication (PLC) channel has been a transmission medium that enables to transfer high-speed digital data through the classical electrical wires. Channel characteristics of power lines are very important for communications systems design. In order to get the suitable model for power line communications analysis and improve the PLC communication quality, researchers do lots of study about the PLC channel characterizations based on actual measurement and theoretical analysis. This paper reviews the conclusions of recent studies, summaries the characteristics of PLC channel for medium voltage power lines and low voltage power lines. The further research is also put forward.

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Hyla, Marian. "Start-up of large-power synchronous motor with the 6 kV voltage source inverter and microprocessor-controlled unit for excitation supply." Journal of Electrical Engineering 69, no. 2 (March 1, 2018): 156–62. http://dx.doi.org/10.2478/jee-2018-0019.

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Abstract The paper presents idea and practical implementation of a medium voltage synchronous drive with a voltage source inverter in the stator circuit and a microprocessor controlled unit for excitation supply. Construction of both devices was presented, and methods of their cooperation were described. Selected start-up methods of large power synchronous motors were presented. Exemplary realization was discussed. Measurement results of the direct full-voltage start-up and frequency start-up of a real 1.25 MW 6 kV fan drive system were compared and discussed.

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Zhao, Bin. "Biomathematical analysis on impedance measurement during COVID-19 pandemic." Research of Gastric Management and Hepatology 1, no. 1 (February 25, 2023): 01–03. http://dx.doi.org/10.58489/2836-6204/003.

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The coating impedance size can reflect the aging degree of the coating to a certain extent; therefore, the measurement of the coating impedance size can monitor the aging degree of the coating in real time. Since the coating is traditionally considered as an insulating medium, its impedance value before aging is as high as 10^8 Ω or more, it is difficult to achieve accurate impedance measurement, and the current generated by loading by voltammetry at low voltage is very weak and easily affected by external electromagnetic interference noise, and the measurement accuracy is low. In this paper, by pluralizing the high impedance, establishing the mathematical model of differential amplification circuit, and then using sinusoidal fitting in which processing, so that the obtained signal is more accurate during COVID-19 pandemic.

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Abdullah, A. Z., M. Isa, M. N. K. H. Rohani, S. A. S. Jamalil, A. N. N. Abdullah, and N. Azizan. "Development of smart online partial discharge monitoring system for medium voltage power cable." International Journal of Power Electronics and Drive Systems (IJPEDS) 10, no. 4 (December 1, 2019): 2190. http://dx.doi.org/10.11591/ijpeds.v10.i4.pp2190-2197.

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This paper presents, the development of smart online partial discharge (PD) monitoring system for medium voltage (MV) underground power cable. PD monitoring is the highly efficient tool to monitor insulation degradation for high voltage (HV) equipment in order to avoid failures or breakdown. Selection of improved technology and performance of PD detection sensor, effective measurement technique and smart user friendly of graphical user interface (GUI) system are contributed towards the development of efficient monitoring system. This paper addresses three main aspects which are needed in completing the monitoring system. They are, the use of Rogowski coil (RC) as detection sensor, processing unit using Alterra board and integrated with GUI PD monitoring system for underground cable using LabVIEW. The monitoring system is compared to the conventional method with the PD signal used is measured from the real on-site measurement in order to analyse its performance. The analysis is performed in MATLAB and LabVIEW software’s environment and the maximum peak of PD signal is enabled to view using GUI which complete with the location information of PD source. Furthermore, this paper has contributed to solve the problem in selection the simplified and practical approach for PD sensor and monitoring system. In the perspective of automated condition monitoring, this smart online PD monitoring system provides a complete solution towards latest industrial revolutions

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Fusiek, Grzegorz, and Pawel Niewczas. "Construction and Evaluation of an Optical Medium Voltage Transducer Module Aimed at a 132 kV Optical Voltage Sensor for WAMPAC Systems." Sensors 22, no. 14 (July 15, 2022): 5307. http://dx.doi.org/10.3390/s22145307.

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This paper reports on the construction and characterization of an optical voltage transducer module for applications in the field of wide-area monitoring, protection, and control (WAMPAC). The optical medium voltage transducer (MVT) module was designed to be combined with a capacitive voltage divider (CVD) to form a voltage sensor intended for 132 kV high voltage (HV) networks. The MVT module comprises a combination of a piezoelectric transducer (PZT) and a fiber Bragg grating (FBG) as a core optical sensing element. Changes in the input voltage across the PZT translate into strain being detected by the FBG. The resultant FBG peak wavelength can be calibrated in terms of the input voltage to obtain a precise voltage measurement. The module was experimentally evaluated in the laboratory, and its performance was assessed based on the requirements specified by the IEC standards for electronic voltage transformers and low power voltage transformers. The results of accuracy tests demonstrate that the MVT module is free from hysteresis, within the experimental error, and is capable of simultaneously meeting the requirements for 0.1 metering and 1P protection classes specified by the IEC 60044-7 and IEC 61869-11 standards.

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Landini, Marco, Giovanni Mazzanti, and Riccardo Mandrioli. "Procedure for Verifying Population Exposure Limits to the Magnetic Field from Double-Circuit Overhead Power Lines." Electricity 2, no. 3 (September 12, 2021): 342–58. http://dx.doi.org/10.3390/electricity2030021.

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The verification of the limits of the population’s exposure to the magnetic field generated by double-circuit power lines from field measurements carried out on site is not trivial. It requires knowledge of the power line current instant values during the measurement period, the determination of the relationship between current and field at the measurement points (made more complex by the double-circuit overhead line configuration) and the use of that relationship to extrapolate the field values. Nevertheless, the verification of exposure limits for double-circuit power lines from on-site measurements is often conducted with rough, or not particularly stringent, procedures. A practical and straightforward procedure of general validity for non-optimized double-circuit lines is proposed here. No specific measurement position or conductors disposition knowledge is required as well as no complex three-dimensional finite element method code is necessary. The procedure, potentially also applicable to high- and extra-high-voltage lines, is validated on a medium-voltage (15 kV) double-circuit overhead power line study case. Exposure limits assessment suggests that if the line is operated at its rated capacity (230/285 A), the 3 μT quality target is missed. Results are provided with a 95% confidence interval ranging from ±100 nT to ±140 nT in all the cases.

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Armano, Giuliano, and Paolo Attilio Pegoraro. "Assessing Feature Importance for Short-Term Prediction of Electricity Demand in Medium-Voltage Loads." Energies 15, no. 2 (January 13, 2022): 549. http://dx.doi.org/10.3390/en15020549.

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The design of new monitoring systems for intelligent distribution networks often requires both real-time measurements and pseudomeasurements to be processed. The former are obtained from smart meters, phasor measurement units and smart electronic devices, whereas the latter are predicted using appropriate algorithms—with the typical objective of forecasting the behaviour of power loads and generators. However, depending on the technique used for data encoding, the attempt at making predictions over a period of several days may trigger problems related to the high number of features. To contrast this issue, feature importance analysis becomes a tool of primary importance. This article is aimed at illustrating a technique devised to investigate the importance of features on data deemed relevant for predicting the next hour demand of aggregated, medium-voltage electrical loads. The same technique allows us to inspect the hidden layers of multilayer perceptrons entrusted with making the predictions, since, ultimately, the content of any hidden layer can be seen as an alternative encoding of the input data. The possibility of inspecting hidden layers can give wide support to researchers in a number of relevant tasks, including the appraisal of the generalisation capability reached by a multilayer perceptron and the identification of neurons not relevant for the prediction task.

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Babaev, Stanislav, Ravi Shankar Singh, Sjef Cobben, Vladimir Ćuk, and Allan Downie. "Multi-Point Time-Synchronized Waveform Recording for the Analysis of Wide-Area Harmonic Propagation." Applied Sciences 10, no. 11 (June 2, 2020): 3869. http://dx.doi.org/10.3390/app10113869.

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This paper focuses on studying the phenomenon of harmonic distortion propagation through distribution networks. This phenomenon is governed by a combination of factors involving the nature of harmonic loads and their dynamic interaction, the influence of background voltage distortion, and harmonic impedance values. The objective of the proposed research includes evaluation of the network response at different nodes to harmonic current injections via utilizing a time-synchronized distributed measurement system. The study is performed in a fully controlled and flexible test network with three medium voltage/low voltage (MV/LV) distribution substations and several managed LV harmonic sources, namely PV inverter, single-phase EV charger and emulated harmonic load with reference current injections. A selection of the results is analyzed and interpretation of the observed phenomena is given with implications that synchronized harmonic measurements can be considered as potential powerful instruments for analyzing power quality disturbances.

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Xiang, Yu, Paulo F. Ribeiro, and Joseph F. G. Cobben. "Optimization of State-Estimator-Based Operation Framework Including Measurement Placement for Medium Voltage Distribution Grid." IEEE Transactions on Smart Grid 5, no. 6 (November 2014): 2929–37. http://dx.doi.org/10.1109/tsg.2014.2343672.

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Journal articles on the topic 'Medium Voltage measurement'

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