Journal articles: 'Switching transient overvoltages'

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Keitoue, Samir, Ivan Murat, Božidar Filipović-Grčić, Alan Župan, Ivana Damjanović, and Ivica Pavić. "Lightning caused overvoltages on power transformers recorded by on-line transient overvoltage monitoring system." Journal of Energy - Energija 67, no. 2 (June 2, 2022): 44–53. http://dx.doi.org/10.37798/201867279.

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Transient overvoltages generated by lightning strikes or switching operations represent a significant risk to bushings and windings of power transformers. They cause stress on the insulation system and can, over time, cause dielectric failure and damage to power transformers. Many transformer failures are reported as dielectric failures and they are not necessarily linked to any particular event when they occur but may be the result of prior damage from transient overvoltage events. Lightning and switching overvoltage waveforms appearing at transformer terminals in real operating conditions may significantly differ from standard impulse voltage waveforms used during laboratory testing. The number and amplitudes of overvoltages which stress the insulation depend on various parameters such as the lightning strike density in the considered area, since it determines how often the transformer is stressed by lightning overvoltages. Since the overvoltage amplitudes at transformer terminals are usually unknown, an on-line overvoltage transient recorder can be used with the ability to sample, analyse and store transients in real-time. In this paper, an on-line transient overvoltage monitoring system (TOMS) for power transformers is presented that is capable to continuously record in real-time various kinds of transient overvoltages such as lightning or switching overvoltages. Special attention is paid to lightning caused transient overvoltages recorded at the terminals of 150 MVA power transformer. Recorded waveforms originating from lightning strikes to overhead lines are correlated with data from the lightning location system (LLS) and supervisory control and data acquisition (SCADA) system. Collected data about overvoltage stresses can be used as the basis for the assessment of the transformer insulation condition, estimation of health index and for analysis of various kinds of events such as faults or equipment failures.

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Furgał, Jakub, Maciej Kuniewski, and Piotr Pająk. "Analysis of Internal Overvoltages in Transformer Windings during Transients in Electrical Networks." Energies 13, no. 10 (May 22, 2020): 2644. http://dx.doi.org/10.3390/en13102644.

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Due to the increasing requirements for the reliability of electrical power supply and associated apparatus, it is necessary to provide a detailed analysis of the overvoltage risk of power transformer insulation systems and equipment connected to their terminals. Exposure of transformer windings to overvoltages is the result of the propagation condition of electromagnetic waves in electrical networks and transformer windings. An analysis of transformer winding responses to transients in power systems is of particular importance, especially when protection against surges by typical overvoltage protection systems is applied. The analysis of internal overvoltages in transformers during a typical transient related to switching operations and selected failures is of great importance, particularly to assess the overvoltage exposure of insulation systems in operating conditions. The random nature of overvoltage phenomena in electrical networks implies the usage of computer simulations for the analysis of overvoltage exposures of electrical devices in operation. This article presents the analysis of the impact of transient phenomena in a model of a medium-voltage electrical network during switching operations and ground faults on overvoltages in the internal insulation systems of transformer windings. The basis of the analysis is simulations of overvoltages in the windings, made in the Electromagnetic Transients Program/Alternative Transients Program (EMTP/ATP) using a model with lumped parameters of transformer windings. The analysis covers the impact of the cable line length and the ground fault resistance value on internal overvoltage distributions.

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Pannila, Earl A. R. L., and Mahesh Edirisinghe. "Signatures of Transient Overvoltages in Low Voltage Power Systems in Tea Factories and Their Implications on Insulation Deterioration and Allied Power Quality Issues." Journal of Electrical and Computer Engineering 2021 (November 19, 2021): 1–12. http://dx.doi.org/10.1155/2021/2623965.

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Electrical equipment and supply cables demand a better quality of supply, with the recent advancements in integrated sensitive solid-state controls. Divergently, proliferated heavy inductive motors and some performance additions based on power electronics have introduced power quality issues to the network. Thus, this study mainly investigates the impact of switching transients generated by electromechanical machines in industrial power systems on insulation deterioration while taking transient overvoltages due to capacitor bank switching also to support. Transients with a high rate of rise are likely to catalyze the degradation of the insulation quality and break down the insulating material through ionization. These steeply passing overvoltage stresses let partial discharges ensue, which can attack the insulation over long service. To unveil this danger, 314 common-mode transient waveforms were measured in the electrical machines of five tea factories in Sri Lanka, in a 50 ms measurement window, taken in 55 measuring attempts. Most of the transients observed are in the form of a damped oscillatory waveform tailed by fast exponential collapse. That correlates to insulation degradation having a very steep rise as 30.04 V/ns, the highest at the withering section. When machines are heavily loaded, situations tend to generate transients with high amplitudes. There were transient bursts that spread as 426.3 ms, while 14 ns fast rise times were recorded from withering motors. Unlike electrical resonance and power-frequency overvoltages, electromagnetic switching transients last even less than 100 ms. To underline this, an analysis of the frequency domain of transients was also presented, which proves high density of high-frequency components reaching 107 kHz range. Accepting the fact that frequency and amplitude are always under the influences of innumerable dynamics, the observational evidence of the study endorses that electrical stress built by the transient nature of the factories reduces the life expectancy of electrical insulation.

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Leman, Jon T., and Robert G. Olsen. "Bulk FDTD Simulation of Distributed Corona Effects and Overvoltage Profiles for HSIL Transmission Line Design." Energies 13, no. 10 (May 14, 2020): 2474. http://dx.doi.org/10.3390/en13102474.

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Power system load growth and transmission corridor constraints are driving industry activity in the area of high surge impedance loading (HSIL). Examples include compact structure design and uprating existing transmission lines. Recent research relating electric field uniformity to transmission line capacity and critical flashover voltage underscored the need for better overvoltage data to quantify insulation margins for HSIL design. To that end, this work extends the finite difference time domain (FDTD) method with distributed corona losses to transmission lines with bundled conductors. The model was adapted for practical use in high-volume statistical transient simulation and applied to an example 500 kV line. Transients included line energization and trapped charge reclosing. Overvoltage profiles and statistical distributions were generated from 9500 simulations obtained by random breaker close timing and variation in line length and altitude. Distributed corona losses reduced 98th percentile line-to-ground switching overvoltages by 4%–14% of nominal. The estimated line-to-ground switching surge flashover probability was 54%–80% lower with corona loss. Corona had less impact on line-to-line overvoltages, but the effects were still notable. Results highlight the importance of considering detailed overvoltage profiles and accounting for corona loss attenuation when seeking to carefully quantify insulation design margins.

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Girgis, A. A., C. M. Fallon, J. C. P. Rubino, and R. C. Catoe. "Harmonics and transient overvoltages due to capacitor switching." IEEE Transactions on Industry Applications 29, no. 6 (1993): 1184–88. http://dx.doi.org/10.1109/28.259731.

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Sadeghkhani, Iman, Abbas Ketabi, and Rene Feuillet. "The Study of Switching Overvoltages under Power System Restoration Scenario Using Extended Delta-Bar-Delta Algorithm." International Journal of Emerging Electric Power Systems 14, no. 3 (June 19, 2013): 219–30. http://dx.doi.org/10.1515/ijeeps-2012-0003.

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Abstract This paper presents an intelligent approach to evaluate switching overvoltages during power equipment energization. Switching action is one of the most important issues in power system restoration schemes. This action may lead to overvoltages that can damage some equipment and delay ‎power system restoration. In this work, transient overvoltages caused by power equipment energization are analyzed and estimated using artificial neural network (ANN)-based approach. Three learning algorithms, delta-bar-delta (DBD), extended delta-bar-delta (EDBD), and directed random search (DRS), were used to train the ANNs. In the cases of transformer and shunt reactor energization, ANNs are trained with the worst case scenario of switching angle and remanent flux which reduce the number of required simulations for training ANN. Also, for achieving good generalization capability for developed ANN, equivalent parameters of the network are used as ANN inputs. The simulated results for a partial of 39-bus New England test system, ‎show that the proposed technique can estimate the peak values and ‎duration of switching overvoltages with good accuracy and EDBD algorithm presents best performance.

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Schwarz, K. K. "Transient switching overvoltages and compatibility of rotating machine insulation." Power Engineering Journal 1, no. 1 (1987): 43. http://dx.doi.org/10.1049/pe:19870008.

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Hanus, Oleksii, and Kostiantyn Starkov. "STUDY OF THE NATURE OF OVERVOLTAGES IN THE ELECTRICAL NETWORK ARISING FROM VOLTAGE TRANSFORMERS." Bulletin of the National Technical University "KhPI". Series: Energy: Reliability and Energy Efficiency, no. 1 (2) (July 2, 2021): 28–36. http://dx.doi.org/10.20998/2224-0349.2021.01.05.

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A non-linear dynamic mathematical model of voltage transformer has been considered and overvoltages arising on the elements of voltage transformer equivalent circuit during transient processes have been investigated. The influence of voltage transformer secondary circuit capacitance on overvoltage multiplicity in the primary circuits and the duration of transients has been determined. The advantages of approximation of nonlinearity of voltage transformers by hyperbolic sine are used. Mathematical expressions determining the nature of changes in the forced and free components of the transient process in an electrical network with a voltage transformer have been obtained. It is shown that with the increase of the electric network capacitance the duration of the transition process damping increases and the frequency of the forced oscillations and the level of overvoltage decrease. It is proved that even small, in comparison with the primary nominal sinusoidal voltage, aperiodic components of the voltage transient process can lead to significant overvoltages during voltage transformer outages. It has been substantiated that both the secondary resistance and the switching torque influence the overvoltage multiplicity arising in the primary winding of voltage transformers. It is shown that the closed secondary winding worsens the disconnection process of non-linear inductance of voltage transformers. The values to which overvoltages increase in this case are determined. According to the results of calculations it is determined that with open secondary winding of voltage transformers the duration of transient process significantly increases. It has been found that the decrease of frequency of forced oscillations, which occurs in this case, is accompanied by an increase of currents in the primary winding of the voltage transformer, which is dangerous in terms of thermal stability of the winding insulation. It is shown, that closing the secondary winding of voltage transformers leads to significant reduction of transient damping time. It is suggested that this algorithm can be used to provide a rapid breakdown (suppression) of ferroresonant processes. The effectiveness of such a measure of stopping of ferroresonance processes as short-term shunting of secondary winding of voltage transformers has been investigated. The correlation of parameters of electric networks (capacity of busbar sections, nonlinearity of characteristics of voltage transformers, disconnection torque, etc.) at which ferroresonance process may occur and consideration of which may allow, in terms of prevention of ferroresonance processes, to identify substations (electric networks) that require more detailed research has been determined. The results of analytical studies were tested in the electric networks of JSC "Kharkivoblenergo" and used in the electricity distribution system for the selection of specific voltage transformers for certain configurations of electrical networks.

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Barzkar, Ashkan, and Mona Ghassemi. "Precise Evaluation of Repetitive Transient Overvoltages in Motor Windings in Wide-Bandgap Drive Systems." Vehicles 4, no. 3 (July 19, 2022): 697–726. http://dx.doi.org/10.3390/vehicles4030040.

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The increasing interest in employing wide-bandgap (WBG) drive systems has brought about very high power, high-frequency inverters enjoying switching frequencies up to hundreds of kilohertz. However, voltage surges with steep fronts, caused by turning semiconductor switches on/off in inverters, travel through the cable and are reflected at interfaces due to impedance mismatches, giving rise to overvoltages at motor terminals and in motor windings. The phenomena typically associated with these repetitive overvoltages are partial discharges and heating in the insulation system, both of which contribute to insulation system degradation and may lead to premature failures. In this article, taking the mentioned challenges into account, the repetitive transient overvoltage phenomenon in WBG drive systems is evaluated at motor terminals and in motor windings by implementing a precise multiconductor transmission line (MCTL) model in the time domain considering skin and proximity effects. In this regard, first, a finite element method (FEM) analysis is conducted in COMSOL Multiphysics to calculate parasitic elements of the motor; next, the vector fitting approach is employed to properly account for the frequency dependency of calculated elements, and, finally, the model is developed in EMTP-RV to assess the transient overvoltages at motor terminals and in motor windings. As shown, the harshest situation occurs in turns closer to motor terminals and/or turns closer to the neutral point depending on whether the neutral point is grounded or floating, how different phases are connected, and how motor phases are excited by pulse width modulation (PWM) voltages.

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Kaczmarek, Michał, and Dariusz Brodecki. "Transformation of Transient Overvoltages by Inductive Voltage Transformers." Sensors 21, no. 12 (June 17, 2021): 4167. http://dx.doi.org/10.3390/s21124167.

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Overvoltage transients occur after any type of switching activity in a power network, such as breaker operation, fault occurrence/clearance and rapid load change. This distortion of voltage is transformed to the secondary circuit of a voltage transformer. The maximum values of such impulses may many times exceed the rated value of its secondary voltage. This can lead to malfunction of measuring or protection devices connected to the secondary circuit of a voltage transformer and even their damage. The paper presents the application of determined values of ratio error at harmonics of the inductive voltage of the transformer to predict the value of transformed slow-front transient overvoltage to their secondary circuits. This will help to prevent malfunction of measuring or protection devices connected to the secondary side of the voltage transformer and increase their safety of operation. The inductive voltage transformer equivalent circuit for transformation of higher frequency components of distorted voltage must be extended with internal capacitances of windings. This is caused by the fact that the resonance phenomenon of the slow-front transient overvoltage results from leakage inductance and capacitance of primary winding, not from the magnetic core. Therefore, this behaviour is independent from the value of the applied voltage.

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Florkowski, Marek, Jakub Furgał, and Maciej Kuniewski. "Propagation of Overvoltages in the Form of Impulse, Chopped and Oscillating Waveforms in Transformer Windings—Time and Frequency Domain Approach." Energies 13, no. 2 (January 8, 2020): 304. http://dx.doi.org/10.3390/en13020304.

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This paper describes a comparison of overvoltage propagation in transformer windings. Expanding and evolving electrical networks comprise various classes of transient waveforms, related to network reconfigurations, failure stages and switching phenomena, including new sources based on power electronics devices. In particular, the integration of renewable energy sources—mainly solar and wind—as well as expanding charging and energy storage infrastructure for electric cars in smart cities results in network flexibility manifested by switching phenomena and transients propagation, both impulse and oscillating. Those external transients, having a magnitude below the applied protection level may have still a considerable effect on winding electrical insulation in transformers, mainly due to internal resonance phenomena, which have been the root cause of many transformer failures. Such cases might occur if the frequency content of the incoming waveform matches the resonance zones of the winding frequency characteristic. Due to this coincidence, the measurements were performed both in time and frequency domain, applying various classes of transients, representing impulse, chopped (time to chopping from 1 µs to 50 µs) and oscillating overvoltages. An additional novelty was a superposition of a full lighting impulse with an oscillating component in the form of a modulated wavelet. The comparison of propagation of those waveforms along the winding length as well as a transfer case between high and low voltage windings were analyzed. The presented mapping of overvoltage prone zones along the winding length can contribute to transformer design optimization, development of novel diagnostic methodology, improved protection concepts and the proper design of modern networks.

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Wen, Caiquan, Zheng Yang, Yitao Lu, Yongfeng Huang, Hanliang Lin, Zhiyuan Zhang, Taiyu Chen, and Yingnan Liu. "Study on Very Fast Transient Overvoltage Characteristics of Gas-Insulated Switchgear Substation Based on Hybrid Reactive Power Compensation." Mathematical Problems in Engineering 2022 (September 29, 2022): 1–10. http://dx.doi.org/10.1155/2022/2914983.

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In recent years, gas-insulated switchgear (GIS) substations have become widely used in power systems. Due to their compact structure, extremely high oscillation frequencies are prone to extremely high oscillation transient overvoltages or very fast transient overvoltages (VFTOs) when the isolating switch or circuit breaker is operated. The characteristics of these special fast transient processes in GIS and the effect of hybrid reactive power compensation (HRPC) on these fast transient processes were studied. A simulation of the GIS model was established, and based on the transient model of HRPC and the theory of the transmission line, the effects of VFTO produced by HRPC switching operation and the parameters of HRPC on VFTO were studied and the differences in the characteristics of VFTOs in substations with or without HRPC. Based on the conclusions of our study on the influence of HRPC on VFTO, the inhibitory effects of a ferrite magnet ring and an inhibitor busbar on VFTO were verified.

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Mohan, T. Murali, and T. Ramya Durga. "EFFECT OF GENERATING CAPACITOR BANK SWITCHING TRANSIENT OVER VOLTAGES AND MITIGATING OF TRANSIENT OVERVOLTAGES." International Journal of Engineering Applied Sciences and Technology 04, no. 07 (December 25, 2019): 113–18. http://dx.doi.org/10.33564/ijeast.2019.v04i07.017.

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Tempelaar, H. G. "Determination of transient overvoltages caused by switching of high voltage motors." IEEE Transactions on Energy Conversion 3, no. 4 (1988): 806–14. http://dx.doi.org/10.1109/60.9356.

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Serebryakov, Alexander S., Vladimir L. Osokin, and Dmitry E. Dulepov. "TRANSIENT ANALYSIS OF ACTIVE-CAPACITIVE CIRCUITS WHEN CAPACITORS ARE CONNECTED IN SERIES." Vestnik Chuvashskogo universiteta, no. 1 (March 30, 2022): 156–70. http://dx.doi.org/10.47026/1810-1909-2022-1-156-170.

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Active-capacitive and inductive-capacitive circuits with series connection of capacitors are widely used in the electric power industry to compensate for reactive power. In traction power supply systems for railways electrified with alternating current, compensation units perform two tasks: under heavy load, they maintain a given railway throughput, and under low load, they reduce power losses in the traction network. Therefore, the installation of compensation in the traction network must be at least two-stage, i.e. have two reactive power values and, accordingly, two capacitance values. The value of reactive power in such installations is regulated in steps by switching individual sections of capacitors, which are connected in series. When switching capacitors in series, previously unknown specific transients can occur. They cause significant overvoltages on the capacitors. It is shown that in some cases the calculation of transient processes in active-capacitive circuits with capacitors connected in series using the well-known classical method gives results that differ from the actual values. The purpose of the article is to provide a previously unknown theoretical basis for calculating transient processes in electrical circuits containing series-connected capacitors using the example of active-capacitive DC circuits. The studies carried out are of practical importance, since in modern electrical installations, thyristor switches are used as switching equipment, in which the shunting of one capacitor in the compensating installation occurs at the maximum voltage on the operating capacitor. In this case, overvoltages exceeding the assumed values are possible, in the limit up to double the amplitude value of the supply voltage. A theoretical substantiation of this phenomenon is given by the example of the analysis of the transient process in an active-capacitive circuit with two consecutively connected capacitors.

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Jurišić, Bruno, Ivo Uglešić, Alain Xemard, and Françoise Paladian. "Case study on transformer models for calculation of high frequency transmitted overvoltages." Journal of Energy - Energija 63, no. 1-4 (July 4, 2022): 262–72. http://dx.doi.org/10.37798/2014631-4186.

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Events such as lightning, switching of vacuum circuit breaker or switching operations in gas insulated substation (GIS) generate high frequency overvoltages. An equipment in a transmission or a distribution system has to be protected against such phenomena. Unfortunately, the traditional transformer models available in Electromagnetic transient simulations program (EMTP-like) software packages are not capable of representing transformer behavior in a transient state, which includes high frequencies. Moreover, high frequency transformer models are often too complex or require confidential information on transformer geometry. However, in the design stage of insulation coordination it is particularly important to accurately calculate transmitted overvoltages through transformers. In the scope of this paper two different transformer models for high frequency, are developed in an EMTP-type software program. The first model named “Black box” derives solely from the values measured on the transformer terminals and does not require any knowledge of the transformer inner geometry. The second model named “Grey box”, is based on a lumped RLC parameters network, whose values are derived from the simple geometry of the transformer window and from the nameplate data. Furthermore, the models’ capabilities to characterize a transformer at high frequencies are analyzed. The case study is done on a distribution transformer which is to be located inside a power plant. The transmitted overvoltages calculated with the models in the EMTP-type software program are compared with measurements.

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Barakou, Steennis, and Wouters. "Accuracy and Reliability of Switching Transients Measurement with Open-Air Capacitive Sensors." Energies 12, no. 7 (April 11, 2019): 1405. http://dx.doi.org/10.3390/en12071405.

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Contactless capacitive (open-air) sensors are applied to monitor overvoltages near overhead line terminations at a substation or at the transition from underground cables to overhead lines. It is shown that these sensors, applied in a differentiating/integrating measuring concept, can result in excellent characteristics in terms of electromagnetic compatibility. The inherent cross-coupling from open-air sensors to other phases is dealt with. The paper describes a method to calibrate the sensor to line coupling matrix based on assumed 50 Hz symmetric phase voltages and in particular focuses on uncertainty analysis of assumptions made. Network simulation shows that predicted maximum overvoltages agree within typically 7% compared to reconstructed values from measurement, also with significant cross-coupling. Transient voltages from energization of an (extra-)high voltage connection can cause large and steep rising ground currents near the line terminations. Comparison with results obtained by a capacitive divider confirms the intrinsic capability in interference rejection by the differentiating/integrating measurement methodology.

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Brenna, Morris, Federica Foiadelli, and Dario Zaninelli. "An Analysis of Transient Overvoltages during the Energization of Electric Ship Propulsion Systems." Scientific World Journal 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/458068.

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This paper addresses the resonance phenomena that can occur in an isolated distribution system during transient events such as repeated energizations or power converter switching. In particular, the aim of this study is to analyze the energization of an onboard radial distribution system installed on an electric ship and to determine how the various leakage parameters that can cause resonance problems such as high peak overvoltages when the circuit breaker is closed are relevant. The paper presents a detailed model of whole distribution system, which is validated using infield measurements that refer to a real case in which these events damaged the ships transformers, causing it to be removed from duty.

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Fediv, Yevhen, Olha Sivakova, Vladyslav Lysiak, and Mykhailo Korchak. "Switching overvoltages protection of power electronics converters with gate turn-off thyristors." Energy engineering and control systems 7, no. 2 (2021): 103–10. http://dx.doi.org/10.23939/jeecs2021.02.103.

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Using the developed models in the “Simulink” visual programming environment of the “Matlab” application package using the “SimPowerSystem” and “Simscape Electrical” libraries, a comparative analysis of methods and techniques for limiting switching overvoltages in power converters, which are controlled by unlocking two-operation thyristors, was performed. The choice of a specific means of limitation is individual for each converter and depends on many factors - the power of the converter, the current-voltage characteristics of thyristors, the parameters of the power supply, and so on. Studies have shown that the most effective protection against voltage pulses with short duration and significant amplitude is the use of “Transient Voltage Suppressors” limiting diodes, the action of which is based on the use of avalanche breakdown during the time of thyristor unlocking.

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Thukaram, D., H. P. Khincha, and Sulabh Khandelwal. "Estimation of switching transient peak overvoltages during transmission line energization using artificial neural network." Electric Power Systems Research 76, no. 4 (January 2006): 259–69. http://dx.doi.org/10.1016/j.epsr.2005.07.001.

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Robson, Stephen, Abderrahmane Haddad, Simon Dennis, and Foroozan Ghassemi. "Non-Contact Measurement and Analysis of Trapped Charge Decay Rates for Cable Line Switching Transients." Energies 13, no. 5 (March 3, 2020): 1142. http://dx.doi.org/10.3390/en13051142.

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During reclosure of 275 kV cable circuits used for voltage control, excessive overvoltages were observed on the network. Such events cause onerous and costly failures. Transient simulations have shown that the normal voltage on its own cannot generate such excessive switching overvoltages. Initial investigations by the network operator pointed towards trapped charge on the unearthed as the cause of the failures. Measurement of these trapped charge voltages and their slow decay without interfering with the charge has, to the author’s knowledge, not been done before in an operational substation. This work introduces a technique to measure trapped charge at a 275 kV substation using the Electrostatic Field Mill. Since the electric field is a proxy measurement of surface voltage, field mills can also be used to measure voltage. In this paper, an on-site substation measurement setup using an electrostatic field mill has been developed for the non-contact measurement of trapped charge voltage on a 275 kV underground cable circuit following switching operations at a National Grid substation. Results of field measurements within the substation and laboratory experimentation are discussed. It is demonstrated that with adequate calibration, achieved by using the known pre-switching power frequency steady state voltage, the slowly decaying DC voltage caused by the cable trapped charge can be measured using this non-contact technique. The correlation between the instantaneous time constant and the relative humidity is also analysed.

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Khuziashev, Rustem, Igor Kuzmin, and Iluza Irkagalieva. "Classification of diagnostic features of transient signals in the electric power industry." E3S Web of Conferences 288 (2021): 01036. http://dx.doi.org/10.1051/e3sconf/202128801036.

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Problems of practical implementation of traveling wave fault location caused by the registration of signals of different nature are considered. Analysis of the experimentally recorded traveling waves made it possible to divide them into 4 groups caused by partial discharges, lightning overvoltages, scheduled switching and fault commutations. The network dispatchers only needs the fault commutation information. Traveling waves recorded near the place of their origin have different meanings of diagnostic signs. The magnitude of the pre-alarm noise, the number of pulses in the signal and the duration of the signal are used as diagnostic indicators. These three diagnostic signs allow one to recognize each of the 4 causes of the travelling waves.

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SHVETS, Nikolay N., Nikolay M. LEPEKHIN, Valery P. MIROSHNICHENKO, Alexander I. ORLOV, Vladimir S. SYSOEV, Igor V. DUBOV, and Evgeniy V. BASOV. "Electric Power Distribution System Overvoltage Protection Devices." Elektrichestvo, no. 2 (2022): 4–18. http://dx.doi.org/10.24160/0013-5380-2022-2-4-18.

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Surge protection devices of limiting and combined types used in 0.4 kV electric power distribution networks are described, and results of their experimental studies are presented. The devices have been developed in four earthquake-resistant designs with the use of new-generation nonlinear resistors (varistors) and controlled vacuum arresters. The developed protective devices are intended to limit transient overvoltages, which occur under the influence of man-made, natural and switching electromagnetic pulses, to a safe level, which for the developed design versions of protective devices lies in the range from 1.5 kV to 4.0 kV, and to remove pulses of high-energy currents (up to 500 kJ in a pulse). The article presents the results from studies of the switching characteristics of the developed protective devices in their nominal (multiple) and maximum (single) operation modes, with the measurement of limit voltages at their terminals. The practical effectiveness of using the combined type protective devices is estimated, and the performance characteristics of protection devices from different manufacturers are given.

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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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Xue, Haoyan, and Marjan Popov. "Analysis of switching transient overvoltages in the power system of floating production storage and offloading vessel." Electric Power Systems Research 115 (October 2014): 3–10. http://dx.doi.org/10.1016/j.epsr.2014.01.021.

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Kuczek, T., M. Florkowski, and W. Piasecki. "Transformer Switching With Vacuum Circuit Breaker: Case Study of PV Inverter LC Filters Impact on Transient Overvoltages." IEEE Transactions on Power Delivery 31, no. 1 (February 2016): 44–49. http://dx.doi.org/10.1109/tpwrd.2015.2437199.

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Wouters, Peter, Armand van Deursen, and Mischa Vermeer. "Methodology and accuracy for non-invasive detection of switching transient overvoltages from compensation coils connected to power transformers." IET Science, Measurement & Technology 14, no. 2 (March 1, 2020): 173–81. http://dx.doi.org/10.1049/iet-smt.2019.0228.

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Avent, B. L., D. F. Peelo, J. H. Sawada, and L. A. Snider. "Limitation of transient recovery voltage and slow-front overvoltages in series compensated transmission lines and in reactor switching." Electric Power Systems Research 45, no. 1 (April 1998): 13–18. http://dx.doi.org/10.1016/s0378-7796(97)01213-3.

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Tajdinian, Mohsen, Mehdi Allahbakhshi, Sandeep Biswal, Om P. Malik, and Donya Behi. "Study of the Impact of Switching Transient Overvoltages on Ferroresonance of CCVT in Series and Shunt Compensated Power Systems." IEEE Transactions on Industrial Informatics 16, no. 8 (August 2020): 5032–41. http://dx.doi.org/10.1109/tii.2019.2951332.

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Musa, Y. I., A. J. F. Keri, J. A. Halladay, A. S. Jagtiani, J. D. Mandeville, B. Johnnerfelt, L. Stenstrom, A. H. Khan, and W. B. Freeman. "Application of 800-kV SF6 dead tank circuit breaker with transmission line surge arrester to control switching transient overvoltages." IEEE Transactions on Power Delivery 17, no. 4 (October 2002): 957–62. http://dx.doi.org/10.1109/tpwrd.2002.803698.

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Andreev, Anton. "SIMULATION OF A TRANSIENT PROCESS IN A 10 KV DISTRIBUTION NETWORK WITH A SINGLE-PHASE EARTH FAULT." Electrical and data processing facilities and systems 18, no. 2 (2022): 5–12. http://dx.doi.org/10.17122/1999-5458-2022-18-2-5-12.

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Relevance At the moment, finding single-phase earth faults in networks with isolated and compensated neutral is still a problem with ambiguous solutions. Existing earth fault protection devices are relevant only in special cases. In networks with a large number of outgoing connections and an extensive circuit, these protections are not able to provide absolutely selective triggering. Therefore, this problem is especially relevant for urban electric networks, since these networks are characterized by both the mass of lines and the heterogeneous nature of the load. Also, the difficulty in detecting damage is the secrecy of the transmission lines, since in these networks they are mainly made by cables. To unambiguously determine the earth fault, in urban distribution networks, earth fault protection is most often used in conjunction with the sequential shutdown method. The use of this method greatly facilitates the determination of an earth fault, but at the same time it is destructive in relation to the power supply of consumers. Since urban distribution networks supply densely populated areas with electric energy, this disadvantage further exacerbates the existing problem. In order to limit these negative consequences, it is possible to make switches by regrouping the network into sections. Such switching will allow you to quickly identify a damaged line and eliminate short-term disconnections of consumers during the search for a ground fault. However, the application of this method is accompanied by switching in the distribution network during a single-phase earth fault. Therefore, it is necessary to study the transient process that occurs during such switching in 10 kV distribution networks in order to verify the applicability of such switching. Also, this study will set the vector for further scientific research in this area. Aim of research Simulation of the transient process that occurs when combining 10 kV networks for parallel operation during a single-phase earth fault. Research methods The methodological basis in this article is mathematical simulation modeling. Results Overvoltages arising during switching in a 10 kV network during a ground fault are considered. Their analysis and the conditions of applicability of the switches performed when determining the earth fault in distribution cable networks are carried out.

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Xin, Y. L., Y. H. Yang, B. N. Zhao, L. Xu, Z. Y. Yu, and W. H. Tang. "Configuration of suppression schemes against high-frequency transient reignition overvoltages caused by shunt reactor switching-off in offshore wind farms." International Journal of Electrical Power & Energy Systems 141 (October 2022): 108170. http://dx.doi.org/10.1016/j.ijepes.2022.108170.

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Srećko Bojić, A. Sekso Telento, and I. Dolić. "Electromagnetic compatibility in various kinds of substations in Croatian transmission networks and mitigation measures." Journal of Energy - Energija 59, no. 1-4 (August 22, 2022): 83–89. http://dx.doi.org/10.37798/2010591-4282.

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In the last two decades have been studied the conditions of electromagnetic compatibility (EMC) in different kind of substations in transmission networks of Croatia. Investigations have been done by measuring method using special measuring technique and also by computing simulations. In this paper will be shown conditions of EMC which have been studied by measuring method during normal or fault switching operations of disconnectors and circuit breakers. Conditions of EMC with particular stress on transient voltages in secondary circuits within various kind of transmission network objects have been carefully studied (AIS, GIS, old and new substation design type, rated voltages from 110 kV to 400 kV). In the paper will be given the review of some main data from those investigations made in the long period of time. Then main findings will be given and the differences in EMC conditions will be shown taking into account various parameters such as: design details of substations (distances, cable types, protective measures etc.). Also, it will be given a review of measuring methods and tools (oscilloscopes with low and deep acquisition memory, statistical tools for data processing, etc.). Generally, it was shown that overvoltatges in secondary equipment follows normal or Gaussian statistical distribution from which some typical data have been taken, such as 98% - probability values etc. Consequently, different kind of the mitigation measures have been proposed in cases of high overvoltages in secondary circuits. Typically, changes in earthing systems, in cable sheets connections etc. have been proposed to utilities. All proposed measures have been tested by measuring methods too and the effects have been very satisfactory in ensuring EMC conditions within substations. Some most interesting ways in reducing high level of TEVR in GIS substations will be shown in pictures. Given results and effects of mitigation measures in Croatian transmission network substations clearly show that the best method is experimental investigation which usually was followed by some necessary mitigation measures which ensure the conditions of EMC within substations according to international standards and recommendations.

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Szewczyk, M. "Multi-spark modeling of very fast transient overvoltages for the purposes of developing HV and UHV gas-insulated switchgear and of conducting insulation co-ordination studies." Bulletin of the Polish Academy of Sciences Technical Sciences 65, no. 6 (December 1, 2017): 871–82. http://dx.doi.org/10.1515/bpasts-2017-0094.

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AbstractVery fast transient overvoltages (VFTO) originate from steep voltage breakdowns in SF6gas that are inherent to operation of any switching device of the gas-insulated switchgear (GIS) type. For power stations with voltage ratings exceeding 500 kV, the ratio between equipment rated- and withstand-voltage levels becomes relatively low, which causes the VFTO peak values to reach the component’s insulation withstand-voltage levels, thus becoming a design factor for high- and ultra-high voltage GIS. While well-established approach to VFTO analyses involves only single VFTO events (the so-called single-spark approach), there is often the need to analyze the entire VFTO generation process, for which the multi-spark approach to VFTO modeling is to be employed. The multi-spark approach allows one to evaluate the VFTO impact on the GIS disconnector design along with the impact of the VFTO on selection and dimensioning of the VFTO damping solutions. As the multi-spark approach to VFTO modeling is now being increasingly used in UHV GIS developments as well as for the insulation co-ordination studies of power stations, the present paper is motivated by the need to report on the VFTO multi-spark modeling approach and to lay a common ground for development works that are supported extensively with VFTO simulations. The paper presents physical assumptions and modeling concepts that are in use in such modeling works. Development of the multi-spark GIS disconnector model for VFTO simulations is presented, followed by an overview of examples of the model application for the GIS development works and for insulation co-ordination studies.

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CAZACU, Emil, and Lucian PETRESCU. "ASPECTE CALITATIVE ȘI CANTITATIVE ALE FENOMENUL DE FEROREZONANȚĂ ÎN INSTALAȚIILE ELECTRICE DE JOASĂ TENSIUNE." "ACTUALITĂŢI ŞI PERSPECTIVE ÎN DOMENIUL MAŞINILOR ELECTRICE (ELECTRIC MACHINES, MATERIALS AND DRIVES - PRESENT AND TRENDS)" 2020, no. 1 (February 10, 2021): 1–14. http://dx.doi.org/10.36801/apme.2020.1.8.

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The phenomenon of ferroresonance is generated by the interaction between nonlinear magnetic devices and capacitive elements in an electrical installation in which losses are reduced and which are constantly supplied by at least one energy source. Feroresonance is manifested by the appearance of overvoltages and overcurrents in the installation with strongly distorted waveforms. Also, the phenomenon is accompanied by other disturbances of the quality of electricity (voltage fluctuations, asymmetries, noise, etc.), which propagate in the network affecting the proper functioning of the entire installation. In addition, unlike linear resonance, ferroresonance allows the manifestation of several stable states (modes) for the same parameters of the network, these being imposed by the initial conditions in the installation and the moment of occurrence of the phenomenon. Thus, the vulnerability to low resonance of a low voltage installation has become an indicator of electricity quality. This paper presents a procedure for calculating and investigating this phenomenon based on the analysis of numerical solutions of systems of differential equations (nonlinear and non-autonomous), which models the transient phenomena that initiate the appearance of ferroresonance (usually switching processes). Also, modern means of investigation are used (3D visualizations in the phase plan or Poincaré diagrams), imposed by the difficulty of the quantitative analysis both in dynamic regime and in stationary regime of ferroresonance. In addition, methods and procedures are proposed to mitigate the effects of the ferroresonance phenomenon on equipment or network elements in electrical distribution installations.

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SADEGHKHANI, IMAN, ABBAS KETABI, and RENE FEUILLET. "CONTROL OF SHUNT REACTOR OVERVOLTAGES BY CONTROLLED SWITCHING DURING POWER SYSTEM RESTORATION." Journal of Circuits, Systems and Computers 21, no. 07 (November 2012): 1250051. http://dx.doi.org/10.1142/s021812661250051x.

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The shunt reactors located on both line terminals and substation bus-bars are commonly used on long extra high voltage (EHV) transmission systems for controlling voltage during load variations. In a small power system that appears in an early stage of a black start of a power system, an overvoltage could be caused by core saturation on the energization of a shunt reactor with residual flux. The most effective method for the limitation of the switching overvoltages is controlled switching since the magnitudes of the produced transients are strongly dependent on the closing instants of the switch. A harmonic index has been introduced that it's minimum value is corresponding to the best-case switching time. In addition, in this paper an artificial neural network (ANN) is used to estimate the optimum switching instants for real time applications. ANN is trained with equivalent circuit parameters of the network, so that developed ANN is applicable to every studied system. To verify the effectiveness of the proposed index and accuracy of the ANN-based approach, two case studies are presented and demonstrated.

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Zhou, Zikai, Yaxun Guo, Xiaofeng Jiang, Gang Liu, Wenhu Tang, Honglei Deng, Xiaohua Li, and Ming Zheng. "Study on Transient Overvoltage of Offshore Wind Farm Considering Different Electrical Characteristics of Vacuum Circuit Breaker." Journal of Marine Science and Engineering 7, no. 11 (November 13, 2019): 415. http://dx.doi.org/10.3390/jmse7110415.

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For the study of transient overvoltage (TOV) in an offshore wind farm (OWF) collector system caused by switching off vacuum circuit breakers (VCBs), a simplified experimental platform of OWF medium-voltage (MV) cable collector system was established in this paper to conduct switching operation tests of VCB and obtain the characteristic parameters for VCB, especially dielectric strength parameters; also, the effectiveness of the VCB reignition model was verified. Then, PSCAD/EMTDC was used to construct the MV collector system of the OWF, and the effects of normal switching and fault switching on TOV amplitude, steepness, and the total number of reignition of the VCB were studied, respectively, with the experimental parameters and traditional parameters of dielectric strength of the VCB. The simulation results show that when the VCB is at the tower bottom, the overvoltage amplitude generated by the normal switching is the largest, which is 1.83 p.u., and the overvoltage steepness of the fault switching is the largest, up to 142 kV/μs. The overvoltage amplitude and steepness caused by switching off VCB at the tower bottom faultily with traditional parameters are about 2 and 1.5 times of the experimental parameters under the same operating condition.

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Prabowo, Rizky Drajat, and Badaruddin Badaruddin. "ANALISA INRUSH CURRENT DAN TRANSIENT OVERVOLTAGE TRANSFORMATOR 292 MVA DENGAN PENGUJIAN LINE CHARGING STUDI KASUS PADA PLTGU CILEGON." Transmisi 24, no. 1 (February 17, 2022): 29–37. http://dx.doi.org/10.14710/transmisi.24.1.29-37.

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Kehandalan sistem dan peralatan yang memberikan supply listrik kepada konsumen menjadi fokus utama dalam upaya penyediaan energi listrik. Untuk memastikan kehandalan tersebut dilakukan serangkaian pengujian dalam sistem kelistrikan, salah satu pengujian tersebut adalah pengujian line charging. Pengujian line charging adalah kondisi dimana mesin pembangkit beroperasi isolated untuk memberikan supply ke saluran transmisi, peralatan transmisi dan ke beban, dalam situasi yang dikondisikan. Peralatan penting yang memiliki kemungkinan failure dalam pengujian tersebut adalah transformator. Dampak operasi transformator dalam pengujian line charging adalah terjadinya inrush current dan transient overvoltage. Hal tersebut memiliki potensi mengurangi kehandalan transformator. Penelitian ini dilakukan untuk mengetahui nilai inrush current, transient overvoltage dan mengetahui dampaknya terhadap transformator dari data hasil simulasi pemodelan dan data aktual pengujian line charging. Berdasarkan hasil analisa yang dilakukan inrush current dan transient overvoltage terbesar diperoleh dari pemodelan dengan metode switching pada 52L dengan nilai 6.56 kA dan 307.3 kV. Nilai transient overvoltage dari hasil simulasi menunjukkan hasil 2.5 kali dari tegangan nominalnya, hal ini jika dilakukan terus menerus akan menyebabkan kegagalan operasi transformator. Metode yang paling efektif untuk menurunkan inrush current adalah metode switching pda 52G dengan sequential switch, dengan metode ini didapatkan penurunan inrush current sebesar 83.6 % dari metode 52G.

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Reza Shariatinasab, Behrooz Vahidi, Seyed Hossein Hosseinian, and Akihiro Ametani. "Application of ANN and Genetic Algorithm for Evaluation the Optimum Location of Arresters on Power Networks due to the Switching Overvoltages." Journal of Energy - Energija 60, no. 1-4 (August 17, 2022): 10–15. http://dx.doi.org/10.37798/2011601-4255.

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Switching surges are of primary importance in insulation co-ordination of EHV lines, as well as in designing insulation of apparatuses. The magnitude and shape of the switching overvoltages vary with the system parameters, network configuration and the point-on-wave where the switching operation takes place. This paper presents an artificial neural network (ANN) based approach to estimate the peak value of overvoltages and the global risk of failure generated by switching transients during line energizing or re-energizing in different nodes of a power network. Then a genetic algorithm (GA) based method is developed to find the best position of surge arresters on power networks so as to minimize the global risk of the network.

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Abbaszadeh, Amir, Mehrdad Abedi, and Ali Doustmohammadi. "Comparison of transformer modeling on riser pole arresters behavior during switching transients." Archives of Electrical Engineering 66, no. 4 (December 20, 2017): 717–30. http://dx.doi.org/10.1515/aee-2017-0054.

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Abstract Arresters are widely used in power systems to protect other equipment against overvoltages. However, in some conditions, they can’t operate successfully. One of the disturbances leading to the failure of the riser pole arresters is the ferroresonance overvoltages. In this paper, at first the influence of different transformer simulation models of ATP software on the occurrence of ferroresonance is studied and then the effect of ferroresonance on the riser pole arrester has been scrutinized through the thermal and electrical performance of the arrester in an underground distribution system. The results show that the arrester temperature rises due to energy dissipation in a ferroresonance circumstance, which indeed may result into the explosion of the arrester. Also, applying different models of the transformer in the ATP software and comparing the results, it is shown that the available models do not show the same effect on the arrester.

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41

Ozawa, J., T. Yamagiwa, M. Hosokawa, S. Takeuchi, and H. Kozawa. "Suppression of Fast Transient Overvoltage During Gas Disconnector Switching in GIS." IEEE Power Engineering Review PER-6, no. 10 (October 1986): 43–44. http://dx.doi.org/10.1109/mper.1986.5527612.

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Ozawa, J., T. Yamagiwa, M. Hosokawa, S. Takeuchi, and H. Kozawa. "Suppression of Fast Transient Overvoltage during Gas Disconnector Switching in GIS." IEEE Transactions on Power Delivery 1, no. 4 (1986): 194–201. http://dx.doi.org/10.1109/tpwrd.1986.4308048.

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Shariatmadar, S. M. M., and S. M. J. Jafarian. "Application of Minimum-time Optimal Control System in Buck-Boost Bi-linear Converters." Engineering, Technology & Applied Science Research 7, no. 4 (August 9, 2017): 1753–58. http://dx.doi.org/10.48084/etasr.1217.

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In this study, the theory of minimum-time optimal control system in buck-boost bi-linear converters is described, so that output voltage regulation is carried out within minimum time. For this purpose, the Pontryagin's Minimum Principle is applied to find optimal switching level applying minimum-time optimal control rules. The results revealed that by utilizing an optimal switching level instead of classical switching patterns, output voltage regulation will be carried out within minimum time. However, transient energy index of increased overvoltage significantly reduces in order to attain minimum time optimal control in reduced output load. The laboratory results were used in order to verify numerical simulations.

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Li, Jinyuan, Meiting Cui, Yujie Du, Junji Ke, and Zhibin Zhao. "Influence of Parasitic Inductances on Switching Performance of SiC MOSFET." E3S Web of Conferences 64 (2018): 04005. http://dx.doi.org/10.1051/e3sconf/20186404005.

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Compared to the silicon power devices, silicon carbide device has shorter switch time. Hence, as a result of the faster transition of voltage (dv/dt) and current (di/dt) in SiC MOSFET, the influence of parasitic parameters on SiC MOSFET’s switching transient is more serious. This paper gives an experimental study of the influence of parasitic inductance on SiC MOSFET’s switching characteristics. Most significance parameters are the parasitic inductances of gate driver loop and power switching loop. These include the SiC MOSFET package’s parasitic inductance, interconnect inductance and the parasitic inductance of dc link PCB trace. This paper therefore focuses on analysis and comparison of different parasitic parameters under various operation conditions in terms of their effect on overvoltage, overcurrent and switching power loss.

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Bödeker, Christian, Sarah Rugen, and Nando Kaminski. "Dynamic Voltage Rise Control (DVRC) Applied to SiC Bipolar Junction Transistors." Materials Science Forum 821-823 (June 2015): 826–29. http://dx.doi.org/10.4028/www.scientific.net/msf.821-823.826.

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Considering the development of faster power electronic switches, especially silicon carbide (SiC) devices, parasitic elements, such as stray inductances and capacitances, become more and more crucial. Overvoltages caused by stray inductances in combination with fast switching transients can destroy the devices at turn-off. In this paper the implementation of the DVRC circuit for silicon carbide bipolar junction transistors (BJTs) is investigated. The DUT was Fairchild`s FSICBH057A120 (VCES= 1200 V, Ron= 57 mΩ).

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Sun, Jixing, Kaixuan Hu, Yongzhi Fan, Jiyong Liu, Shengchun Yan, and Yan Zhang. "Modeling and Experimental Analysis of Overvoltage and Inrush Current Characteristics of the Electric Rail Traction Power Supply System." Energies 15, no. 24 (December 8, 2022): 9308. http://dx.doi.org/10.3390/en15249308.

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High-speed EMUs (electric multiple-units) frequently pass through the phase-separation zone during operation. Overvoltage generated during the operation of the vehicle-mounted circuit breaker has a long duration and high waveform steepness, which accelerates the service life of the vehicle-mounted equipment and is likely to cause insulation failures. For the above-mentioned problems, the operating overvoltage characteristics of high-speed EMU were obtained by traction substation-catenary-EMUs system (SCES) analysis and experiments, thus deriving the influences of the closed phase angle and the residual magnetism of the vehicle-mounted transformer on operating overvoltage. The results showed that the voltage phase of the catenary significantly affected the operating overvoltage, and the closed switching overvoltage was small at 0–40°, 140–210° and 320–350°. The voltage on the primary side of the vehicle-mounted transformer was 60.78 kV, with the transient impact of high-frequency oscillation overvoltage of 22.71 kV, and an initial period of oscillation of 0.01 ms. Then, the period became longer, and it took 0.5 ms for the high-frequency oscillation from attenuation to disappearance. Finally, a scheme of series reactance suppression devices was proposed to protect vehicle-mounted voltage transformers. This work is to provide data support for the insulation design and system protection of a traction power supply system.

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Luo, Xin, Xuemin Huang, Chuntao Liu, and Huaan Tan. "The influence of the closing phase angle of AC filter on the action of arrester in ±800 kV Nuozhadu DC transmission project." Advances in Mechanical Engineering 12, no. 2 (February 2020): 168781401985027. http://dx.doi.org/10.1177/1687814019850276.

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The power system is affected by different levels of transient shock caused by different switching angle when AC filter switching on. The shock causes frequent action and aging of lightning arrester. In this article, the causes of frequent action of lightning arrester in Nuozhadu DC project are analyzed by means of power systems computer aided design simulation. The overvoltage, current, and energy of AC filter switching on are also analyzed. The critical angle of the arrester action of AC filters is discussed. The results show that AC filter switching on can affect this group and other groups. When the closing phase angle reaches 12°, the arrester in this group lightnings. When the closing phase angle reaches 18, the arresters in other groups lightning. Finally, the influence of the three phases and the impact which varies with power are also discussed.

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Shpolianskii, O. G. "ANALYSIS OF TRANSIENT PROCESSES DURING ENERGISATION OF THE AC OVERHED TRANSMITION LINE IN THE HIBRID POWER SYSTEMS." Tekhnichna Elektrodynamika 2022, no. 6 (October 27, 2022): 58–62. http://dx.doi.org/10.15407/techned2022.06.058.

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The paper analyses the transients that occur during the energisation of overhead transmission line 750 kV in a hybrid power system. It is shown that the power supply of the AC transmission line from the high voltage direct current transmission allows using converter control system to limit the switching overvoltage and the aperiodic currents. This enriches the list of traditional measures to improve the safety of AC power systems. References 8, tables 2, figures 1.

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Yinbiao, Shu, Han Bin, Lin Ji-ming, Chen Weijiang, Ban Liangeng, Xiang Zutao, and Chen Guoqiang. "Influence of the Switching Speed of the Disconnector on Very Fast Transient Overvoltage." IEEE Transactions on Power Delivery 28, no. 4 (October 2013): 2080–84. http://dx.doi.org/10.1109/tpwrd.2013.2273620.

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Barmada, Sami, Alessandro Formisano, Jesus C. Hernandez, Francisco José J. Sánchez Sutil, and Carlo Petrarca. "Impact of nearby lightning on photovoltaic modules converters." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 41, no. 2 (November 16, 2021): 628–43. http://dx.doi.org/10.1108/compel-06-2021-0209.

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Purpose The lightning phenomenon is one of the main threats in photovoltaic (PV) applications. Suitable protection systems avoid major damages from direct strikes but also nearby strikes may induce overvoltage transients in the module itself and in the power conditioning circuitry, which can permanently damage the system. The effects on the PV system sensibly depend on the converter topology and on the adopted power switch. In the present study, a comparative analysis of the transient response due to a nearby lightning strike (LS) is carried out for three PV systems, each equipped with a different converter, namely, boost, buck and buck–boost, based on either silicon carbide metal oxide semiconductor field effect transistors (SiC MOSFET) or insulated gate bipolar transistors controlled power switch devices, allowing in this way an analysis at different switching frequencies. The purpose of this paper is to present the results of the numerical analysis to help the design of suited protection systems. Design/methodology/approach Using a recently introduced three-dimensional semi-analytical method to simulate the electromagnetic transients caused in PV modules by nearby LSs, we investigate numerically the effect of a LS on the electronic circuits connecting the module to the alternate current (AC) power systems. This study adopts numerical simulations because experimental analyses are not easy to perform and does not grant a sufficient coverage of all statistically relevant aspects. The approach was validated in a previous paper against available experimental data. Findings It is found that the load voltage is not severely interested by the strike effects, thanks to the low pass filters present at the converter output, whereas a relatively high overvoltage develops between the negative pin of the inner circuitry and the “ground” voltage reference. The overcurrent present in the active switches is hardly comparable because of the different topologies and working frequencies; however, the highest overcurrent is observed in the buck converter topology, with SiC MOSFET technology, although it shows the fastest decay. Originality/value This research proposes, to the best of the authors’ knowledge, a comprehensive comparison of the indirect lighting strike effects on the converter connected to PV panels. A proper design of the lightning and surge protection system should take into account such aspects to reduce the risk of induced overvoltage and overcurrent transients.

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Journal articles on the topic 'Switching transient overvoltages'

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