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Evaluation Method and Probabilistic Index of voltage sag Severity Considering Point-on-wave

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Journal of Modern Power Systems and Clean Energy 2021年第3期9卷 633-638页

作者： Guopei Wu Qing Zhong Qizhang He Zhong Xu Guangzhou Power Supply Bureau Cooperation GuangzhouChina the School of Electric Power South China University of TechnologyGuangzhouChina

The impact of voltage sag on sensitive devices is related to the time when the sag ***,the point-on-wave of a sag is ***,this paper presents a nov-el approach to evaluate the voltage sag severity considering a random ***,the uncertainty of equipment malfunction is ***,under a given residual voltage,the relationship between the point-on-wave and the duration that the device can withstand is described with a fitting ***,a voltage sag probabilistic index is proposed to describe the *** evaluation procedure is also ***,three types of releasers are tested and analyzed to determine the effectiveness of the proposed *** evaluation method can help instruct electrical engineers establish more well-grounded sag mitigation proposals.

关键词： voltage sag evaluation method severity index probabilistic index

Identification of voltage sag source location using S and TT transformed disturbance power

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Journal of Central South University 2013年第1期20卷 83-97页

作者： Hussain Shareef Azah Mohamed Ahmad Asrul Ibrahim Department of Electrical Electronics and Systems EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 BangiSelangorMalaysia

An alternative method was introduced for voltage sag source location based on S and TT transformed disturbance powers. It is done to avoid the wrong and inconclusive detection of conventional disturbance power method proposed in the literature. Unlike in the case of the traditional method, the proposed method first transforms the recorded voltage and current during the sag event to some special features before calculating the new version of disturbance powers. The effectiveness of the proposed method has been verified through simulation and actual data from an industrial power system. The results show that the presented method can correctly detect the location of voltage sag source.

关键词： power quality voltage sag S transform TT transform signal processing

Reliability improvement in distribution systems employing an integrated voltage sag mitigation method using binary gravitational search algorithm

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Journal of Central South University 2013年第11期20卷 3002-3014页

作者： Salman Nesrullah Mohamed Azah Shareef Hussain Department of Electrical Electronics and Systems EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia

A method for improving the level of reliability of distribution systems is presented by employing an integrated voltage sag mitigation method that comprises a two-staged strategy,namely,distribution network reconfiguration(DNR)followed by DSTATCOM ***,an optimal DNR is applied to reduce the propagated voltage sags during the test *** second stage involves optimal placement of the DSTATCOM to assist the already reconfigured *** gravitational search algorithm is used in the process of optimal DNR and in placing *** assessment is performed using the well-known *** simulation results show that the proposed method is efficient and feasible for improving the level of system reliability.

关键词： voltage sag reliability network reconfiguration DSTATCOM gravitational search algorithm

Impacts of Induction Motor Load on voltage sag Characterization

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Impacts of Induction Motor Load on Voltage Sag Characterizat...

作者： Galal Ali Mohsen Al-Muthanna（加莫森）东南大学

学位级别：硕士

Due to the fast development in electrical devices,which depend on converting AC power system from the grid to DC,those devices become more sensitive to power quality problems and they affected easily by small disturbances in the *** addition,people definition of power quality has changed through last *** do not just want electrical supply to be reliable,they also need their power supply to be highly compatible with their devices and do not cause any shut down to the *** most common power system disturbance is voltage sag(dip).Because industrial loads are the most common and sensitive load in power system,therefore their impacts of power system disturbance are simulated and *** thesis is a research work on impacts of induction motor load on voltage sag characterization caused by faults.A model was chosen to be simulated through DigSilent PowerFactory software and the output data was analyzed using Mathworks MatLab.A fault event happened with the induction motor plant is in its area of *** system was used to study the impacts in two ***,study the impacts of induction motor existence on voltage sag characterization and impact of voltage sag on induction motor slip,induced torque and power ***,study the impact of the quantity of induction motor load on voltage sag *** industrial system was simulated and assumed to have identical 7 production *** is also assumed that every line has the same mechanical ***,the number of production lines in the time of voltage sag was increased from 0 to *** every load number the voltage sag was simulated and it characterization was *** results of this simulation indicate that that duration and depth of voltage sag are severely increased by the existence of voltage *** the other hand,phase-shift and frequency are slightly affected by the voltage *** motor side,slip becomes higher after transient which means that the motor is operati

关键词： Power quality voltage sag Induction motor sag characterization

An optimized compensation strategy of DVR for micro-grid voltage sag

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Protection and Control of Modern Power Systems 2016年第1期1卷 78-85页

作者： Zhengming Li Wenwen Li Tianhong Pan School of Electrical and Information Engineering Jiangsu UniversityZhenjiang 212000Jiangsu ProvinceChina

Introduction:This paper uses a dynamic voltage restorer(DVR)to improve the voltage quality from voltage *** is difficult to satisfy various of compensation quality and time of the voltage sag by using single compensation ***,high-power consumption of the phase jump compensation increases the size and cost of a dynamic voltage restorer(DVR).Methods&Results:In order to improve the compensating efficiency of DVR,an optimized compensation strategy is proposed for voltage sag of micro-grid caused by interconnection and sensitive *** proposed compensation strategy increases the supporting time for long voltage ***:Firstly,the power flow and the maximum compensation time of DVR are analyzed using three basic compensation ***,the phase jump is corrected by pre-sag *** a quadratic transition curve,which involves the injected voltage phases of pre-sag strategy and minimum energy strategy,is used to transform pre-sag compensation to minimum energy compensation of ***:The transition utilizes the storage system to reduce the rate of *** a result,the proposed strategy increases the supporting time for long voltage *** analytical study shows that the presented method significantly increases compensation time of *** simulation results performed by MATLAB/SIMULINK also confirm the effectiveness of the proposed method.

关键词： Micro-grid voltage sag Dynamic voltage restorer Compensation time Optimized compensation strategy

Analysis and Assessment on Distribution voltage sag Based on Stepped Current Protection

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Analysis and Assessment on Distribution Voltage Sag Based on...

Perceived Utility of Premium Power by High-tech Manufacturers

International Conference on Industrial Technology and Management Science(ITMS 2015)

作者： MA Li School of Electrical Engineering Xi’ an University of Science ＆ Technology

The duration of voltage sag caused by fault is depended on the fault clearing time of the protection system. In traditional assessments on voltage sag are simply assumed that the duration obeys some distribution of random or is a constant value. In order to depict the duration of voltage sags more precisely, time characteristic of stepped current protection and protection scope of instantaneous current protection are taken into consideration, the two demarcation points of the protection operation on line are determined, the protection operation time of every segment is analyzed. An example is simulated by PSCAD/EMTDC software, and it is shown that more reasonable assessment is obtained by precise duration of voltage sag.

关键词： voltage sag duration stepped current protection protection zone Assessment

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Journal of Modern Power Systems and Clean Energy 2020年第2期8卷 287-295页

作者： Yuanqian Ma Xianyong Xiao Yang Wang Ying Wang Zixuan Zheng College of Electrical Engineering and Information Technology Sichuan UniversityChengduChinaand she is also with the Faculty of Mechanical Engineering&AutomationZhejiang Sci-Tech UniversityHangzhouChina College of Electrical Engineering and Information Technology Sichuan UniversityChengduChina

The valuation of premium power based on perceived utility(PU,i.e.,perceived effectiveness or satisfaction degree of customers)and their willingness to pay has been researched for *** of the remaining challenges is the accurate evaluation of *** is the foundation of premium power evaluation,and it is essential for the decision-making process of investments on premium power by high-tech manufacturers(HTMs).This paper presents a framework to effectively evaluate *** this framework,factors influencing PU were classified to be quantitative and *** indication system(IS)was then constructed based on those influencing ***,PU was evaluated by the IS,considering psychological perception and decision-making behavior of *** effectiveness of the proposed PU-evaluation framework was demonstrated through field case studies.

关键词： Premium power voltage sag perceived utility influencing factors indication system

sag Source Location and Type Recognition via Attention-based Independently Recurrent Neural Network

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Journal of Modern Power Systems and Clean Energy 2021年第5期9卷 1018-1031页

作者： Yaping Deng Xinghua Liu Rong Jia Qi Huang Gaoxi Xiao Peng Wang School of Electrical Engineering Xi’an University of TechnologyXi’an 710048China School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731China School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore

Accurate sag source location and precise sag type recognition are both essential to verifying the responsible party for the sag and taking countermeasures to improve power *** this paper,an attention-based independently recurrent neural network(IndRNN)for sag source location and sag type recognition in sparsely monitored power system is ***,the given inputs are voltage waveforms collected by limited meters in sparsely monitored power system,and the desired outputs simultaneously contain the following information:the located lines where sag occurs;the corresponding sag types,including motor starting,transformer energizing and short circuit;and the fault phase for short *** essence,the responsibility of the proposed method is to automatically establish a nonlinear function that relates the given inputs to the desired outputs with categorization labels as few as possible.A favorable feature of the proposed method is that it can be realized without system parameters or *** proposed method is validated by IEEE 30-bus system and a real 134-bus *** results demonstrate that the accuracy of sag source location is higher than 99%for all lines,and the accuracy of sag type recognition is also higher than 99%for various sag sources including motor starting,transformer energizing and 7 different types of short ***,a comparison among different monitor placements for the proposed method is conducted,which illustrates that the observability of power networks should be ensured to achieve satisfactory performance.

关键词： Independently recurrent neural network sag source location sag type recognition voltage sag attention mechanism

Performance improvement of complementary feeders using static transfer switch system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 189-200页

作者： Tahir MAHMOOD Mohammad Ahmad CHOUDHRY Department of Electrical Engineering University of Engineering and Technology

The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches （STSs） at critical locations. We develop the STS control logic, which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders＇ thyristor, thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently proposed time delay technique for STS operation. Two different feeders, namely New Exchange, the preferred feeder, and Sector 1-10/2, the alternate feeder of Islamabad Electric Supply COmpany （IESCO）, Pakistan, have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation.

关键词： Complementary feeder Cross current Static transfer switch (STS) Sensitive load voltage sag PSCAD/EMTDC