Academic literature on the topic 'Zero sequence current compensation'
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Journal articles on the topic "Zero sequence current compensation"
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Montoya-Mira, Rafael, Pedro A. Blasco, José M. Diez, Rafael Montoya, and Miguel J. Reig. "Unbalanced and Reactive Currents Compensation in Three-Phase Four-Wire Sinusoidal Power Systems." Applied Sciences 10, no. 5 (March 4, 2020): 1764. http://dx.doi.org/10.3390/app10051764.
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In an unbalanced linear three-phase electrical system, there are inefficient powers that increase the apparent power supplied by the network, line losses, machine malfunctions, etc. These inefficiencies are mainly due to the use of unbalanced loads. Unlike a three-wire unbalanced system, a four-wire system has zero sequence currents that circulate through the neutral wire and can be compensated by means of compensation equipment, which prevents it from being delivered by the network. To design a compensator that works with unbalanced voltages, it is necessary to consider the interactions between it and the other compensators used to compensate for negative-sequence currents and positive-sequence reactive currents. In this paper, through passive compensation, a new method is proposed to develop the zero sequence current compensation equipment. The method does not require iteration algorithms and is valid for unbalanced voltages. In addition, the interactions between all compensators are analyzed, and the necessary modifications in the calculations are proposed to obtain a total compensation. To facilitate the application of the method and demonstrate its validity, a case study is developed from a three-phase linear four-wire system with unbalanced voltages and loads. The results obtained are compared with other compensation methods that also use passive elements.
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Han, Zhao, Xiaoli Wang, Baochen Jiang, and Jingru Chen. "A Control Strategy for Suppressing Zero-Sequence Circulating Current in Paralleled Three-Phase Voltage-Source PWM Converters." Applied Sciences 10, no. 5 (March 2, 2020): 1703. http://dx.doi.org/10.3390/app10051703.
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In microgrids, paralleled converters can increase the system capacity and conversion efficiency but also generate zero-sequence circulating current, which will distort the AC-side current and increase power losses. Studies have shown that, for two paralleled three-phase voltage-source pulse width modulation (PWM) converters with common DC bus controlled by space vector PWM, the zero-sequence circulating current is mainly related to the difference of the zero-sequence duty ratio between the converters. Therefore, based on the traditional control ideal of zero-vector action time adjustment, this paper proposes a zero-sequence circulating current suppression strategy using proportional–integral quasi-resonant control and feedforward compensation control. Firstly, the dual-loop decoupled control was utilized in a single converter. Then, in order to reduce the amplitude and main harmonic components of the circulating current, a zero-vector duty ratio adjusting factor was initially generated by a proportional–integral quasi-resonant controller. Finally, to eliminate the difference of zero-sequence duty ratio between the converters, the adjusting factor was corrected by a feedforward compensation link. The simulation mode of Matlab/Simulink was constructed for the paralleled converters based on the proposed control strategy. The results verify that this strategy can effectively suppress the zero-sequence circulating current and improve power quality.
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Zhou, Jun, and Ke Zheng Cao. "Locating Method of Single-Phase Grounding Fault in Small Current Grounding System Based on Distribution Automation." Applied Mechanics and Materials 321-324 (June 2013): 1423–28. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.1423.
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In case of the arc suppression coil for neutral point grounding of small current grounding system, when single-phase grounding fault occurs, due to the arc suppression coil for fault line of the compensation effect of the zero sequence current, the fault features is not obvious, it can't implement the fault line selection and fault point location. This paper puts forward a method of change fault lines zero sequence current shortly, namely a resistance inductance (RL) series branch parallel in arc suppression coil, the series branch acts on the system shortly and changes arc suppression coil compensation degree temporarily in single-phase grounding fault. The change of zero sequence residual current only appears the loop from the neutral point to the fault point via the fault line, using FTU (feeder terminal units) on lines monitor the change of zero sequence current on each nodes for fault regional location. And prove this theory the feasibility of the by using MATLAB software of system modeling simulation method.
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Jun, Zhou, Cao Ke-Zheng, and Zheng Hong-Xia. "The Study of Fault Location Method Based on FTU Feeder Automation Technology." Open Electrical & Electronic Engineering Journal 7, no. 1 (December 13, 2013): 143–48. http://dx.doi.org/10.2174/1874129001307010143.
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With the development of power distribution automation system, feeder automation technology in the small current grounding system single-phase grounding fault location plays an important role. In the neutral arc suppression coil grounding system, because of the compensation effect of arc suppression coil, the system fault feature is not obvious. This paper puts forward a method of RL series branch parallel in arc suppression coil, when system single-phase grounding fault occurs, the series branch switch gets closed and acts on the neutral, that changes the compensation degree of arc suppression coil to zero sequence current in fault line, the change of zero sequence residual current being the biggest in the fault section from neutral to fault point. FTU is used to monitor the change in each fault line for fault regional location.
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Tian, Shu, Jin Peng He, and Yu Zheng. "The Research Based on Zero Sequence Energy to the Line Selection in Distribution Network." Advanced Materials Research 614-615 (December 2012): 846–49. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.846.
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When single phase-to-ground fault happened in power network with arc suppression coil grounded, capacitor current through fault point is compensated and reduced by installing arc suppression coil. Zero-sequence current’s amplitude and phase of fault lines and sound lines are so similar that it increases the difficulty of selecting the fault line. But the resistance component of zero sequence current has no relationship with the arc extinguishing coil compensation, absolute value of resistance component to the fault lines show the maximum, and zero sequence current’s polarity of fault lines is contrary to sound lines. In this paper, because of the characteristic of resistance component, a method is put forward based on zero sequence energy to the line selection in distribution network, it import auto-reclosing techniques into the line selection. The principle is verified by MATLAB simulator. It has high accuracy to select the fault line with this method.
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Kai, Takaaki, Mitsuhiro Furuse, Takayuki Matsuda, Motonobu Yoshikawa, and Hidehiko Matsusaki. "The improvement of zero-phase-sequence circulating current compensation scheme for balance ground relaying." IEEJ Transactions on Power and Energy 109, no. 3 (1989): 111–18. http://dx.doi.org/10.1541/ieejpes1972.109.111.
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Geng, Jun Mei, and Chun Guang Li. "Leakage Failure and Principle of Underground Low Voltage Grid." Applied Mechanics and Materials 214 (November 2012): 254–58. http://dx.doi.org/10.4028/www.scientific.net/amm.214.254.
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To describe the leakage protection of underground low voltage grid are based on zero-sequence voltage and zero sequence power direction of the current leakage protection and earth leakage protection based on the additional DC power supply two kinds. The paper gives the theoretical analysis of these two kinds of leakage, and unified the three-phase neutral point grounding system and by arc suppression coil grounding the under compensation leakage detection program, that provides a new approach for underground leakage detection.
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Naderipour, Amirreza, Zulkurnain Abdul-Malek, Mohammad Reza Miveh, Mohammad Jafar Hadidian Moghaddam, Akhtar Kalam, and Foad H. Gandoman. "A Harmonic Compensation Strategy in a Grid-Connected Photovoltaic System Using Zero-Sequence Control." Energies 11, no. 10 (October 1, 2018): 2629. http://dx.doi.org/10.3390/en11102629.
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Mitigation of harmonics for a grid-connected inverter is an important element to stabilize the control and the quality of current injected into the grid. This paper deals with the control method of a three-phase Grid-Connected Inverter (GCI) Photovoltaic (PV) system, which is based on the zero-sequence current adjuster. The proposed method is capable of removing the harmonic current and voltage without using any active and passive filters and without the knowledge of the microgrid topology and also impedances of distribution bands and loading conditions. This concept is adopted for the control of a Distributed Generator (DG) in the form of grid-connected inverter. The proposed control can be applied to the grid connected inverter of the PV. The fast dynamic response, simple design, stability, and fast transient response are the new main features of the proposed design. This paper also analyzes the circuit configuration effects on the grid connected inverter capability. The proposed control is used to demonstrate the improved stability and performance.
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Feng, Guoli, Zhihao Ye, Yihui Xia, Heng Nian, Liming Huang, and Zerun Wang. "High Frequency Resonance Suppression Strategy of Three-Phase Four-Wire Split Capacitor Inverter Connected to Parallel Compensation Grid." Energies 15, no. 4 (February 17, 2022): 1486. http://dx.doi.org/10.3390/en15041486.
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With the continuous penetration and development of renewable energy power generation, the distributed grid and the microgrid are becoming increasingly important in modern power systems. In distribution networks and the microgrid, the grid impedance is comparatively large and cannot be ignored. Usually, the parallel compensation is used to improve the grid quality. In the grid with parallel compensation, the large phase angle difference between the impedance of the grid-connected inverter and the impedance of the grid at amplitude intersection will result in high frequency resonance (HFR). Because the inverter shows filter characteristics due to limited bandwidth of the controller, the parallel compensation grid, respectively, performs as the capacitance characteristic and inductance characteristic in different high frequency range. Compared with the three-phase, three-wire system, an additional zero-sequence path exists in the three-phase four-wire split capacitor inverter (TFSCI) system, so that the existing high frequency resonance suppression methods will be not effective. Since the zero-sequence component is neglected, HFR will also occur, in addition to the positive-sequence component and the negative-sequence component. Therefore, in order to suppress the high frequency resonance caused by positive-sequence, negative-sequence and zero-sequence components, an impedance reshaping strategy based on current feedback is proposed in this paper. This proposed method can reshape the amplitude and phase of the inverter impedance in a high frequency range without affecting the performance of the fundamental frequency control and ensure that the inverter contains a sufficient phase margin. Additionally, the proposed method can reshape the impedance of TFSCI within a wide frequency range, which makes it able to cope with the challenge of the parallel compensation degree change. Theoretical analysis and experiments verify the availability of the proposed control strategy.
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Zhu, Yixin, Tao Wang, Liansong Xiong, Gaofeng Zhang, and Xin Qian. "Parallel Control Method Based on the Consensus Algorithm for the Non-Isolated AC/DC Charging Module." Energies 11, no. 10 (October 19, 2018): 2828. http://dx.doi.org/10.3390/en11102828.
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A high-power charging station for electric vehicles usually adopts a parallel structure of multiple power modules. However, due to the parameter differences among power modules, a parallel system always has circulating current issues. This paper takes a non-isolated AC/DC charging module as the research object and proposes a current sharing control strategy for multiple power modules based on the consensus algorithm. By constructing a sparse communication network with the CAN (Controller Area Network) protocol and exchanging current information, accurate current sharing among power modules is realized. Firstly, the zero-sequence circulating current issue is analyzed through a parallel model of the three-phase rectifier, with an improved circulating current restraint strategy proposed based on the zero-sequence voltage compensation. Then, the principle of the consensus algorithm is explained, which is applied to the current sharing control of multiple power modules. Finally, the proposal is tested by the designed simulation and experimental cases. From the obtained results, it can be seen that the proposed control strategy can effectively realize accurate current sharing among multiple power modules and well restrain the zero-sequence circulating current at the input side.
Dissertations / Theses on the topic "Zero sequence current compensation"
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Lau, Wai Keung. "Current-mode DC-DC buck converter with dynamic zero compensation /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?ECED%202006%20LAU.
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Kapidou, Alexandra. "Application for Wind Farm Integration Complying with the Grid Code by Designing an Outer Control Strategy for the Converter." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187686.
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The continuously increasing energy penetration from wind farms into the grid raises concerns regarding power quality and the stable operation of the power system. The Grid Code´s requirements give strict guidelines for a wind farm´s behaviour under faulty or abnormal operating conditions.The primary purpose of this project is the application of a STATCOM for wind farm integration complying with the Grid Code. Towards that, an outer control strategy for the converter is designed so as to regulate the voltage at the point of common coupling by providing reactive power compensation. Thus the safe operation of the grid will be ensured since the wind farm will follow the Grid Code´s standards.The existing Grid Code requires only a positive sequence current controller. This study attempts to investigate whether this is sufficient or not and to examine the possibility of extending the Grid Code requirements so as to incorporate a negative sequence current controller as well. The results support the latter suggestion. Also, the use of SiC devices was also considered in this project.Den ständigt ökande penetrationen av vindenergi i elnätet väcker farhågor om elkvalitet och stabil drift av kraftsystemet. Nätkoden (Grid Code) ger strikta riktlinjer för en vindkraftsparks beteende i felfall och under onormala driftsförhållanden.Huvudsyftet med detta projekt är att använda en STATCOM för integration av vindkraftsparker så att nätkoden uppfylls. I detta projekt utformas en yttre reglerstrategi för omriktaren för att reglera spänningen vid anslutningspunkten för vindkraftsparken genom att tillhandahålla reaktiv effektkompensering. Därigenom uppnås en säker drift av nätet eftersom vindkraftparken kommer att följa nätkoden.Den befintliga nätkoden kräver endast styrning av plusföljdskomponenten av strömmen. Denna studie försöker undersöka om detta är tillräckligt samt undersöka möjligheten för att utvidga nätkoden genom att införa ett krav på styrning av negativ-sekvens ström. Resultaten stöder det sistnämnda förslaget. Även användningen av halvledarkomponenter av kiselkarbid-SiC studerades i detta projekt.
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Ye, Zhihong. "Modeling and Control of Parallel Three-Phase PWM Converters." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/29476.
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This dissertation studies modeling and control issues of parallel three-phase pulse-width modulated (PWM) converters. The converters include three-phase boost rectifiers, voltage source inverters, buck rectifiers and current source inverters.
The averaging of the parallel converters is performed based on a generic functional switching unit, which is called a phase leg in boost rectifiers and voltage source inverters, and a rail arm in buck rectifiers and current source inverters. Based on phase-leg and rail-arm averaging, the developed models are not only equivalent to the conventional three-phase converter models that are based on phase-to-phase averaging, but they also preserve common-mode information, which is critical in the analysis of the parallel converters. The models reveal such parallel dynamics as reactive power circulation and small-signal interaction.
A unique feature of the parallel three-phase converters is a zero-sequence circulating current. This work proposes a novel zero-sequence control concept that uses variable zero-vectors in the space-vector modulation (SVM) of the converters. The control can be implemented within an individual converter and is independent from the other control loops for the converter. Therefore, it greatly facilitates the design and expansion of a parallel system.
Proper operation of the parallel converters requires an explicit load-sharing mechanism. In order to have a modular design, a droop method is recommended. Traditionally, however, a droop method has to compromise between voltage regulation and load sharing. After parametric analysis, a novel droop method using a gain-scheduling technique is proposed. The numeric analysis shows that the proposed droop method can achieve both good voltage regulation and good load sharing.
An interleaving technique is often used in parallel converter systems in order to reduce current ripples. Because of its symmetrical circuit structure, the parallel three-phase converter system can reduce both differential-mode and common-mode noise with a center-aligned symmetrical SVM.
Based on the concept that a symmetrical circuit can reduce common-mode dv/dt noise, a conventional three-phase, four-leg inverter is modified so that its fourth leg is symmetrical to the other three legs. The common-mode dv/dt noise can be practically eliminated with a new modulation strategy. Meanwhile, with a modified control design, the new four-leg inverter still can handle low-frequency common-mode components that occur due to unbalanced and nonlinear load.Ph. D.
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Tománek, Miloslav. "Simulace účinků zkratových proudů v rozvodnách VVN." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217579.
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This thesis is engaged in a theoretical calculation of short-circuit currents in electric power system in compliance with the norm ČSN 60909-0 and first of all with calculation of dynamical and thermal effects of short-circuit currents in HV switching stations in accordance with the norm ČSN 60865-1. Next the thesis is engaged in a production of programs for simulation of mechanical effects of short-circuit currents with respect to a dimensioning of constructional elements of switching station and afterwards in a practical simulation of selected parts of the real switching station type „H“ in Slavkov u Brna.
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Zhang, Yu. "Small-Signal Modeling and Analysis of Parallel-Connected Power Converter Systems for Distributed Energy Resources." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/551.
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Alternative energy resources (such as photovoltaics, fuel cells, wind turbines, micro-turbines, and internal combustion engines) and energy storage systems (such as batteries, supercapacitors, and flywheels) are increasingly being connected to the utility grid, creating distributed energy resources which require the implementation of an effective distributed power management strategy. Parallel-connected power converters form a critical component in such a distributed energy resources system. This dissertation addresses small-signal modeling and analysis of parallel-connected power converter systems operating in distributed energy environments. This work focuses on DC-DC and DC-AC power converters. First, this work addresses the small-signal modeling and analysis of parallel-connected power converters in a battery/supercapacitor hybrid energy storage system. The small-signal model considers variations in the current of individual energy storage devices and the DC bus voltage as state variables, variations in the power converter duty cycles as control variables, and variations in the battery and the supercapacitor voltages and the load current as external disturbances. This dissertation proposes several different control strategies and studies the effects of variations in controller and filter parameters on system performance. Simulation studies were carried out using the Virtual Test Bed (VTB) platform under various load conditions to verify the proposed control strategies and their effect on the final states of the energy storage devices. Control strategies for single DC-AC three-phase power converters are also identified and investigated. These include a novel PV (active power and voltage) control with frequency droop control loop, PQ (active power and reactive power) control, voltage control, PQ control with frequency droop control, and PQ control with voltage and frequency droop control. Small-signal models of a three-phase power converter system with these control strategies were developed, and the impact of parameter variations on the stability of a PV controlled converter were studied. Moreover, a small-signal model of parallel-connected three-phase DC-AC power converters with individual DC power supplies and network is proposed. The simulations carried out in stand-alone and grid-connected modes verify the combined control strategies that were developed. In addition, a detailed small-signal mathematical model that can represent the zero-sequence current dynamics in parallel-connected three-phase DC-AC power converters that share a single DC power source is presented. The effects of a variety of factors on the zero-sequence current are investigated, and a control strategy to minimize the zero-sequence current is proposed. Time-domain simulation studies verify the results. Simulations of a parallel-connected DC-AC power converter system with nonlinear load were carried out. The active power filter implemented in this system provides sharing of harmonic load between each power converter, and reduces harmonic distortion at the nonlinear load by harmonic compensation.
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Pospíšil, Zdeněk. "Indikace zemních spojení na venkovních vedeních." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-264926.
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This master´s thesis deals with the indication and localization of earth faults in overhead lines. Earth fault is the most frequently occurring type of fault in medium voltage overhead lines – it covers approx. 95% of all faults and is very difficult to indicate and localize them correctly and in time with currently available methods on the market. Therefore is very important to study earth fault and its indication, localization. The thesis consists of a theoretical and a practical part. The theoretical part deals with faults in overhead networks with different type of neutral grounding, mainly with one phase to the ground fault in the compensated, ungrounded, solidly grounded and via resistance grounded networks. Most of the theoretical part is dedicated to one phase to the ground fault in the compensated and ungrounded networks, where this type fault is called the earth fault. In the compensated and ungrounded networks is described in details behavior – voltage and current relations during both steady state and transient state earth fault. The theoretical part is further dedicated to detection methods of earth faults and their preconditions for use. There is described also in details the complete procedure of earth fault detection, which includes indication, unhealthy feeder determination and exact position or line section localization. End of the theoretical part is then focused on determination of accuracy requirements for measurement of basic quantities and computation of other parameters. The practical part deals with a work at medium distribution network model, which includes familiarization with the model, detailed verification of its functionality and behavior during the earth fault, obtaining faults records and algorithmization of methods: method of qu – diagram and method of first half - period, which are able to detect unhealthy feeder. This part of the thesis was put together based on a demand of company Mega, corp., which wanted to verify function of both above mentioned and by them not yet tested methods.
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Hartono, Aryudha. "Microgrid Safety and Protection Strategies." Thesis, KTH, Elektroteknisk teori och konstruktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226593.
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One of the challenging issues with the Microgrid is that the bidirectional power flow providedby the distributed generator (DG) which modify the fault current level. Furthermore, theinverter based-renewable energy source (IB-RES) limits the total fault current contributionto the grid due to its thermal capability. Since Microgrid should be able to operate in gridconnectedand islanded mode, protection strategies are needed to solve this challenging issue.By only having IB-RES and battery storage system, the fault condition and normaloperation cannot be distinguished. Apart from fault clearing issue, there is a consideration tostudy the fault isolation in the Microgrid under the limited fault current provided by IB-RES.To have fault isolation capability, the intelligent electrical device (IED) is needed. The firststep is to find a method that can detect a fault under the fault level modification constraint.This thesis presents a zero and negative sequence current protection to detect a fault.However, to make it selective, this protection will be applied directionally. It is common thatthe distribution grid has unbalanced load operation, thus providing zero and negativesequence component in the grid. To apply the directional zero and negative sequence currentprotection, the unbalanced load flow is simulated to distinguish the fault and normaloperation under unbalanced load condition.Safety and regulation are discussed briefly in this thesis. It is important that each of theIB-RES has fault ride-through (FRT) capability that follows a regulation. However, thisregulation is expected to have a coordination with the proposed protection in the Microgridso the reliability, selectivity, and sensitivity can be achieved in grid-connected and islandedmode. This thesis shows the coordination between fuses, IED, and inverter FRT capability.After providing a protection strategy, the adaptability of the proposed protection isassessed regarding of Microgrid expansion. The result shows that by applying the schemeand following the grading margin requirement that is presented in this thesis, the Microgridexpansion will not disrupt the proposed protection coordination. Since it is known that thedistribution grid is expanding its load capacity and microgeneration in continuous basis, it isconvenient that the proposed protection in the IED is expected to be adaptable, means that ithas a fixed IED setting when the grid is expanded. The analysis is performed by electrical transient analysis program (ETAP) and MatlabSimulink. The short circuit analysis, sequence-of-operation, and unbalanced load flow aresimulated by ETAP, while the protection stability is simulated by Matlab Simulink.Ett problem som finns med microgrid är att de distribuerade produktionsgeneratorerna harett dubbelriktat effektflöde som modifierar felströmmen. Dessutom, inverterbaseradeförnyelsebara energikällor (IB-RES) begränsar det totala felströmsbidraget på grund av desstermiska kapacitet. Eftersom microgrids ska vara operativ vid både anslutning till externt nätsamt önätsdrift behövs skyddsstrategier för att kunna hantera fel, speciellt vid önätsdrift.Om endast IB-RES och batterilager används kan feldrift och normal drift inte särskiljas.Bortsätt från felhantering är det viktigt att studera felbortkoppling för microgrid underbegränsad felström som fås av IB-RES. För att kunna åstadkomma felbortkoppling behöveren IED (från engelskans Intelligent Electronic Device). Det första steget är att finna en metodför att kunna detektera fel under fel nivå modifiering. Denna avhandling tittar på att användanoll- och minusföljds ström sekvensskydd för att detektera fel. För att göra skyddet selektivtkommer det att titta på riktningen av effektflödet. I distributionsnät är det vanligt att haobalanserade laster vilket medför noll- och negativa sekvenskomponenter i nätet. För atttillämpa riktningsskydd för noll och negativ sekvens ström simuleras ett obalanserateffektflöde för att särskilja på feldrift och normal drift vid obalanserad last.Säkerhet och förordningar diskuteras kortfattat i denna avhandling. Det är viktigt att varjeIB-RES har en feltålighet som följer vissa förordningar. Denna förordning förväntassamordna det föreslagna skyddet i micronåt så att pålitlighet, selektivitet och känslighet kanåstadkommas vid nätanslutning och önätsdrift. Denna avhandling visar samordningen mellansäkringar, IED och feltåligheten för växelomriktare.Anpassningsförmågan för det föreslagna skyddet bedöms med avseende på expansion avmicrogrid. Resultatet visar att en expansion av ett microgrid inte kommer att störa denföreslagna samordningen om skyddsmetoden och tidsfördröjningskravet som presenteras idenna avhandling följs. Eftersom det är känt att distributionsnätet kommer att fortsätta ökasin lastkapacitet och mikrogenerering, är det lämpligt att skyddet förväntas varaanpassningsbart vilket innebär att det har en fast IED inställning när nätet expanderas.Analysen genomförs med mjukvarorna electrical transient analysis program (ETAP) ochMatlab Simulink. Kortslutningsanalysen, arbetssekvensen och obalanserad lastflödesimuleras av ETAP, medan skyddsstabiliteten simuleras av Matlab Simulink.
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Dehghanikiadehi, Abbas. "Commande vectorielle innovante pour véhicules électriques ou hybrides." Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC012/document.
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Durant ces dernières années, l'intérêt pour les technologies des véhicules à faibles émissions de carbone a fait un bond important à travers l'Union européenne (UE) et au-delà, encouragé en cela par les gouvernements et les constructeurs automobiles. De grands espoirs ont été mis plus récemment dans les véhicules électriques (VE) et les véhicules électriques hybrides (VEH) en tant que technologies clés pour atténuer le changement climatique, améliorer la sécurité énergétique et favoriser une nouvelle branche de l'industrie dans le secteur automobile. Ainsi, l'électrification des transports a été considérée comme une stratégie clé pour réduire les émissions de CO2 dans le secteur des transports. Le principal défi est d’augmenter l’autonomie des véhicules (ce qui a toujours été au coeur de la concurrence des industries du transport), ainsi que la durée de vie des volumineuses et coûteuses batteries. Par conséquent, ceci indique que le rendement du convertisseur de puissance est un des points clés à développer pour les générations des véhicules électriques à venir. L’autre paramètre influant est la qualité de la tension et du courant (en particulier la suppression des harmoniques basses fréquences) qui permet de réduire la taille des filtres d'entrée et de sortie de ces convertisseurs. L'objectif de cette thèse est de parvenir à un meilleur rendement en proposant de nouvelles structures de convertisseur de puissance et des commandes vectorielles modifiées ; le choix de deux onduleurs alimentant un moteur ouvert aux deux extrémités. Après l'analyse étape par étape, modèle théorique, simulation et enfin une mise en oeuvre expérimentale, il a été constaté que les nouvelles méthodes proposées sont compétitives et peuvent s’appliquer aux cas des VEH et des VE afin d’apporter des caractéristiques supérieures en termes d’efficacité et de qualité de tension et de courantOver the last decade, the interest for low-carbon vehicle technologies has surged among both governments and automotive manufacturers across and beyond the European Union (EU). Great hopes have been put, first, on biofuel vehicles and more recently on electric vehicles (EVs) and hybrid electric vehicles (HEVs) as key technologies to mitigate climate change, enhance energy security and nurture new industry branches within the automotive sector. So electrification of vehicles has been seen as a key strategy to reduce CO2 emissions from the transport sector. The main challenge toward EVs and HEVs is to keep driving for longer distance (which has been always fields for competition among traction industries) as well as lifetime battery cells as storage system. As a result, these indicate importance of power converter efficiency as a key gate for next generations of these up-coming vehicles. The next parameter is the quality of output voltage/current (especially by suppressing low-order harmonics) to reduce the size of filtering. The aim of this thesis is to achieve better efficiency and output voltage/current Total Harmonic Distortion (THD) by proposing novel power converter and associated Pulse Width Modulation (PWM) methods while imposing modification on power converter topology. As a result, dual-inverter is proposed to supply open-end motor from both sides. To this aim, three PWM methods are suggested as: The first one, Modified Space Vector Modulation (MSVM) for dual-inverter supplied by single dc source, improves efficiency by 4-5% (while having lower switching losses), and reduces Common Mode Voltage (CMV) levels by 66%, as well. The voltage/current harmonics are analytically analyzed which shows mainly better performance. Effective switching frequency is also reduced by 66% due to the reduction of number of commutations. In the second one, Near State PWM (NSPWM) is adapted for dual-inverter supplied by single dc source in order to eliminate triplen harmonics (therefore Zero Sequence Voltage, ZSV) and improve efficiency (by 3-4%) compared to Space Vector Modulation (SVM). Additionally due to avoiding use of zero vectors, CMV is improved by 66%. While having 8 commutations instead of 12 in SVM, effective switching frequency is improved by 33%. And finally, the third proposed method deals with NSPWM for dual-inverter supplied by two isolated dc sources wherein efficiency and CMV levels show the same performance as previous one. However, in this method, voltage THD is highly reduced compared to SVM. Triplen harmonics of the output voltage are inherently suppressed by the structure. These 3 proposed methods are analytically studied and their performances are step by step simulated in Matlab/Simulink environment. Then the methods are implemented in dualinverter fed open-end motor in laboratory setup; and the results are compared with these of SVM. Finally, it is found that novel proposed methods are so competitive solutions to be applied in HEVs and EVs and bring superior efficiency and voltage/current harmonic features
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Zadeh, Ramin Agha. "Performance control of distributed generation using digital estimation of signal parameters." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/47011/1/Ramin_Agha_Zadeh_Thesis.pdf.
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The Queensland University of Technology (QUT) allows the presentation of a thesis for the Degree of Doctor of Philosophy in the format of published or submitted papers, where such papers have been published, accepted or submitted during the period of candidature. This thesis is composed of seven published/submitted papers, of which one has been published, three accepted for publication and the other three are under review. This project is financially supported by an Australian Research Council (ARC) Discovery Grant with the aim of proposing strategies for the performance control of Distributed Generation (DG) system with digital estimation of power system signal parameters.
Distributed Generation (DG) has been recently introduced as a new concept for the generation of power and the enhancement of conventionally produced electricity. Global warming issue calls for renewable energy resources in electricity production. Distributed generation based on solar energy (photovoltaic and solar thermal), wind, biomass, mini-hydro along with use of fuel cell and micro turbine will gain substantial momentum in the near future. Technically, DG can be a viable solution for the issue of the integration of renewable or non-conventional energy resources. Basically, DG sources can be connected to local power system through power electronic devices, i.e. inverters or ac-ac converters. The interconnection of DG systems to power system as a compensator or a power source with high quality performance is the main aim of this study. Source and load unbalance, load non-linearity, interharmonic distortion, supply voltage distortion, distortion at the point of common coupling in weak source cases, source current power factor, and synchronism of generated currents or voltages are the issues of concern.
The interconnection of DG sources shall be carried out by using power electronics switching devices that inject high frequency components rather than the desired current. Also, noise and harmonic distortions can impact the performance of the control strategies. To be able to mitigate the negative effect of high frequency and harmonic as well as noise distortion to achieve satisfactory performance of DG systems, new methods of signal parameter estimation have been proposed in this thesis. These methods are based on processing the digital samples of power system signals. Thus, proposing advanced techniques for the digital estimation of signal parameters and methods for the generation of DG reference currents using the estimates provided is the targeted scope of this thesis. An introduction to this research – including a description of the research problem, the literature review and an account of the research progress linking the research papers – is presented in Chapter 1.
One of the main parameters of a power system signal is its frequency. Phasor Measurement (PM) technique is one of the renowned and advanced techniques used for the estimation of power system frequency. Chapter 2 focuses on an in-depth analysis conducted on the PM technique to reveal its strengths and drawbacks. The analysis will be followed by a new technique proposed to enhance the speed of the PM technique while the input signal is free of even-order harmonics. The other techniques proposed in this thesis as the novel ones will be compared with the PM technique comprehensively studied in Chapter 2.
An algorithm based on the concept of Kalman filtering is proposed in Chapter 3. The algorithm is intended to estimate signal parameters like amplitude, frequency and phase angle in the online mode. The Kalman filter is modified to operate on the output signal of a Finite Impulse Response (FIR) filter designed by a plain summation. The frequency estimation unit is independent from the Kalman filter and uses the samples refined by the FIR filter. The frequency estimated is given to the Kalman filter to be used in building the transition matrices. The initial settings for the modified Kalman filter are obtained through a trial and error exercise.
Another algorithm again based on the concept of Kalman filtering is proposed in Chapter 4 for the estimation of signal parameters. The Kalman filter is also modified to operate on the output signal of the same FIR filter explained above. Nevertheless, the frequency estimation unit, unlike the one proposed in Chapter 3, is not segregated and it interacts with the Kalman filter. The frequency estimated is given to the Kalman filter and other parameters such as the amplitudes and phase angles estimated by the Kalman filter is taken to the frequency estimation unit.
Chapter 5 proposes another algorithm based on the concept of Kalman filtering. This time, the state parameters are obtained through matrix arrangements where the noise level is reduced on the sample vector. The purified state vector is used to obtain a new measurement vector for a basic Kalman filter applied. The Kalman filter used has similar structure to a basic Kalman filter except the initial settings are computed through an extensive math-work with regards to the matrix arrangement utilized.
Chapter 6 proposes another algorithm based on the concept of Kalman filtering similar to that of Chapter 3. However, this time the initial settings required for the better performance of the modified Kalman filter are calculated instead of being guessed by trial and error exercises. The simulations results for the parameters of signal estimated are enhanced due to the correct settings applied. Moreover, an enhanced Least Error Square (LES) technique is proposed to take on the estimation when a critical transient is detected in the input signal. In fact, some large, sudden changes in the parameters of the signal at these critical transients are not very well tracked by Kalman filtering. However, the proposed LES technique is found to be much faster in tracking these changes. Therefore, an appropriate combination of the LES and modified Kalman filtering is proposed in Chapter 6. Also, this time the ability of the proposed algorithm is verified on the real data obtained from a prototype test object.
Chapter 7 proposes the other algorithm based on the concept of Kalman filtering similar to those of Chapter 3 and 6. However, this time an optimal digital filter is designed instead of the simple summation FIR filter. New initial settings for the modified Kalman filter are calculated based on the coefficients of the digital filter applied. Also, the ability of the proposed algorithm is verified on the real data obtained from a prototype test object.
Chapter 8 uses the estimation algorithm proposed in Chapter 7 for the interconnection scheme of a DG to power network. Robust estimates of the signal amplitudes and phase angles obtained by the estimation approach are used in the reference generation of the compensation scheme. Several simulation tests provided in this chapter show that the proposed scheme can very well handle the source and load unbalance, load non-linearity, interharmonic distortion, supply voltage distortion, and synchronism of generated currents or voltages. The purposed compensation scheme also prevents distortion in voltage at the point of common coupling in weak source cases, balances the source currents, and makes the supply side power factor a desired value.
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Yueh, Tung, and 岳彤. "The Reverse Zero-Sequence Current Compensation Method for Back-to-Back Active Power Conditioners." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/31652358625819747085.
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碩士國立臺灣大學
電機工程學研究所
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In this thesis, a novel reverse zero-sequence current (RZSC) compensation method for three-phase four-wire back-to-back active power conditioner (APC) is proposed. The objective of the APC is to achieve the active and reactive power transmission between two micro-grids. However, for the unbalanced voltage sag micro-grid system, the double-line frequency oscillation exists in the output active/reactive power of the APC. Therefore, this thesis utilizes the positive-/negative-/zero-sequence current to eliminate these oscillation, but the zero-sequence current produces the line frequency ripple voltage on the split capacitors of the dc-bus. The capacitor ripple voltage speeds up the aging process and reduces its life-time. Also, it may exceed the maximum operating voltage and damage the split capacitors, distort the output current of the inverter, or even cause the malfunction of the APC. Therefore, the RZSC method is proposed to compensate the impact of the ripple voltage to the split capacitors. The operation principle of the back-to-back APC under the unbalanced grid voltage is introduced, and the mathematical equation derivation of the proposed RZSC method is presented. Both computer simulations and hardware experimental results are presented to verify the performance of the back-to-back APC with the proposed RZSC method.
Book chapters on the topic "Zero sequence current compensation"
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Wang, Ying, Xiuqing Mu, Yalan Wang, and Zhengyou He. "Research on RPC-SC System for Negative Sequence Current Compensation of Electrified Railway." In Proceedings of the 5th International Conference on Electrical Engineering and Information Technologies for Rail Transportation (EITRT) 2021, 372–80. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-9905-4_44.
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Wu, Linlin, and Shaofeng Huang. "Selectivity of Zero-Sequence Current Backup Protection and Improvement Based on Wide Area Measurement System." In Lecture Notes in Electrical Engineering, 313–21. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-4981-2_34.
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Liu, Jianbao, Xinxin Qin, and Zhonglin Yang. "Analysis of Zero-Sequence Circulating Current in Parallel PWM Inverter System with Difference of Carrier Wave Phases." In Informatics in Control, Automation and Robotics, 453–63. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-25899-2_62.
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Yu, You, Jingfu Tian, and Tao Li. "Research on Setting Calculation of Zero Sequence Current Inverse Time Limit Protection Based on Intelligent Control Grid." In Advances in Intelligent Systems and Computing, 422–26. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-70042-3_61.
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Wang, Zuowei, Hong Zhang, Dongchao Liu, Shiping E., Kanjun Zhang, Haitao Li, Hengxuan Li, and Zhigang Chen. "New Principle of Fault Data Synchronization for Intelligent Protection Based on Wavelet Analysis." In Proceeding of 2021 International Conference on Wireless Communications, Networking and Applications, 850–61. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2456-9_87.
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AbstractIn order to eliminate the influence of the delay error of the sampled value in the data link on the longitudinal differential protection device, this paper proposes a protection data self-healing synchronization algorithm based on wavelet transform to calculate the moment of sudden change. First, calculate the mutation amount of the sampled data at each end in real time. When the mutation amount threshold is exceeded, it is determined that the multi-terminal system has a short-circuit fault. Then, according to the sudden change characteristics of the collected current waveform, the wavelet modulus maximum value is used to extract the fault sudden change time of each end data, based on the fault time at one terminal, the automatic compensation for the time differences between this terminal and others are realized, thus a new sampling sequence is formed. The resynchronized sampling sequences are used to calculate the differential current and braking current after fault to ensure the correct action of the protective device. Through theoretical analysis and simulations, the correctness and effectiveness of the proposed algorithm is verified; in addition, it is shown that this algorithm can improve the reliability of actions by the intelligent protection device, thus realizing protections such as multi-terminal differential, wide-area differential, etc.
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Ding, Mingjin, Lei Xie, Changyu Zhu, Yongmi Zhang, and Cheng Shi. "Zero-Sequence Circulating Current Suppression for Parallel Three-Level Back-to-Back Converters Based on DPWM Hybrid Switching Modulation Strategy." In Advances in Energy Research and Development. IOS Press, 2022. http://dx.doi.org/10.3233/aerd220007.
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A single wind turbine can no longer meet the increasing installed capacity and reliability requirements. Therefore, the power level and stability requirements of the wind power generation system can be improved through the parallel connection of three-level back-to-back converters. However, the zero-sequence circulating current (ZSCC) will distort the three-phase current, increase the power loss and reduce the system efficiency. Therefore, this paper establishes the ZSCC equivalent model of the back-to-back parallel converter, and analyzes the generation principle of the zero-sequence circulating current. In order to reduce the switching loss of the system and increase the system efficiency, a novel DPWM modulation strategy is proposed. At the same time, in order to control the zero-sequence circulating current of the parallel system, a hybrid switching modulation strategy using DPWM1 and DPWM3 based on hysteresis control is proposed. The simulation and experimental results verify the effectiveness of the zero-sequence circulation suppression strategy for the parallel system.
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Kuibida, Vasyl, Stepan Kuybida, and Valentyna Telychko. "CHAPTER 3.4. MODERNIZATION OF PUBLIC ADMINISTRATION IN THE CONDITIONS OF WAR AND ITS PRIMARY ASSIGNMENTS." In International Partnership and Cooperation of Ukraine in Wartime: Collective monograph / edited by D. Nascimento, G. Starchenko, 272–87. NGO «Research and Educational Innovation Center of Social Transformations», 2022. http://dx.doi.org/10.54929/monograph-02-2022-03-04.
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The chapter considers the current problems of transformation of public administration in the war and post-war periods to ensure the livelihood of citizens and the state, by increasing the level of their security and economic capacity. The main task is to provide the Armed Forces of Ukraine and citizens with everything necessary. This provides for the modernization of the military-industrial complex (further MIC), industrial production, including the processing industry, the construction of new engineering networks and structures, re-equipment of old and construction of new construction objects with Nearly zero-energy buildings (further - NZEB), as well as adjustment of the compensation program for labor costs for each employed internally displaced persons (further - IDPs). Analyzing the processes taking place in Ukraine, special attention is paid to the study of the application of adaptive norms of labor legislation in the conditions of martial law and the effectiveness of the implementation of the compensation program for labor costs for each employed person from among IDPs, suggestions are given for their improvement. The article examines the impact of the Association Agreement with the EU, which is part of the deepened comprehensive free trade zone with the EU, on the economy of Ukraine, it is proposed to intensify public-private partnership and create a system of incentives for the construction of modular factories in various sectors of the economy.
Conference papers on the topic "Zero sequence current compensation"
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Pashajavid, Ehsan, and Mohammad Tavakoli Bina. "APF-based cancellation of the source-end zero sequence current." In 2010 International School on Nonsinusoidal Currents and Compensation (ISNCC). IEEE, 2010. http://dx.doi.org/10.1109/isncc.2010.5524485.
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Shim, Jae-hoon, Hyeon-gyu Choi, and Jung-Ik Ha. "Zero-Sequence Current Suppression with Dead-Time Compensation Control in Open-End Winding PMSM." In 2020 IEEE Energy Conversion Congress and Exposition (ECCE). IEEE, 2020. http://dx.doi.org/10.1109/ecce44975.2020.9236316.
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Yueh, Tung, Terng-Wei Tsai, Yaow-Ming Chen, Yih-Der Lee, and Yung-Ruei Chang. "The reverse zero-sequence current compensation strategy for back-to-back active power conditioners." In 2016 IEEE Energy Conversion Congress and Exposition (ECCE). IEEE, 2016. http://dx.doi.org/10.1109/ecce.2016.7855509.
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Mademlis, Georgios, Yujing Liu, Nimananda Sharma, and Xiaoliang Huang. "Circulating Current Reduction in Common DC-Link Power-HIL for Drives using SVM with Zero-Sequence Compensation." In IECON 2020 - 46th Annual Conference of the IEEE Industrial Electronics Society. IEEE, 2020. http://dx.doi.org/10.1109/iecon43393.2020.9254744.
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Xiao, Qingpu, and Longyu Qin. "Single Phase Grounding Fault Location Method based on the Change of the Zero Sequence Current Along with Compensation Degree." In 2021 IEEE 5th Conference on Energy Internet and Energy System Integration (EI2). IEEE, 2021. http://dx.doi.org/10.1109/ei252483.2021.9713374.
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Kercher, Michael, Wensong Yu, and Iqbal Husain. "Feedforward Deadtime Compensation Using Current Zero Crossing Detection." In 2022 IEEE Energy Conversion Congress and Exposition (ECCE). IEEE, 2022. http://dx.doi.org/10.1109/ecce50734.2022.9947454.
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Kase, T., Y. Kurosawa, and P. Beaumont. "Problems associated with zero sequence compensation applied to distance protection." In 2006 IEEE Power Engineering Society General Meeting. IEEE, 2006. http://dx.doi.org/10.1109/pes.2006.1709278.
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Starling, Leonardo Muller V., Filipe Dias de Oliveira, Sidelmo M. Silva, and Braz de J. Cardoso Filho. "Operation of dynamic voltage restorers without zero sequence compensation capability." In 2010 9th IEEE/IAS International Conference on Industry Applications - INDUSCON 2010. IEEE, 2010. http://dx.doi.org/10.1109/induscon.2010.5739958.
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Qipeng Song, Zhongdong Yin, Chengxi Dai, Changyin Zhang, Weidong Shang, and Zhonghua Huang. "A novel approach to eliminate zero-sequence harmonics current." In APCCAS 2008 - 2008 IEEE Asia Pacific Conference on Circuits and Systems (APCCAS). IEEE, 2008. http://dx.doi.org/10.1109/apccas.2008.4746402.
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Zhou, Xuesong, Kairui Guo, Youjie Ma, and Weibao Zhong. "Zero-sequence Circulating Current Suppression Strategy for Microgrid Inverters." In 2021 IEEE International Conference on Mechatronics and Automation (ICMA). IEEE, 2021. http://dx.doi.org/10.1109/icma52036.2021.9512596.
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