电工技术学报2024，Vol.39Issue(20)：6431-6443,13.DOI:10.19595/j.cnki.1000-6753.tces.231455
抽水蓄能电机转子匝间短路无传感器检测方法
Sensorless Detection Method of Rotor Inter-Turn Short Circuit in Pumped Storage Motors
摘要
Abstract
As an important part of renewable and clean energy,pumped storage power generation has been developing at a high rate in recent years.Due to the complexity and non-linearity of the pumped storage power generation system,its operation may be affected by certain factors and become abnormal,resulting in poor power supply quality.The rotor winding inter-turn insulation(ITI)deterioration process is slow,and the early weak faults are difficult to detect in time.This paper uses the positioning bar(PB)of pumped storage motors(PSMs)as a detection component to avoid inter-turn short circuit(ITSC)faults.Its induced electromotive force(IEMF)can effectively react to the health level of the rotor winding's ITI. Firstly,the relationship between the stray and main flux is derived by introducing the attenuation coefficient method.The characteristic harmonics of the PB's IEMF in the ITSC state are obtained.Accordingly,the harmonic amplitude ratio(HAR)threshold detection method is proposed.Secondly,a two-dimensional electromagnetic simulation model is constructed according to the operating parameters of PSM,and the evolution law of the IEMF's time/frequency domain characteristics before and after the ITSC fault are analyzed.The HAR threshold detection method is verified.Finally,combined with the signal conditioning device,the PB's IEMF information under different ITSC degrees is collected.The HARs of multiple periodic signals are calculated,a statistical box plot is constructed,and the fault detection threshold is set. The simulation results show that the IEMF's time-domain peak value of PB decreases under normal,2 turns-ITSC,and 4 turns-ITSC states.The corresponding IEMF's time-domain peaks are 6.74 mV,6.3 mV,and 5.96 mV under no-load conditions,while 7.33 mV,6.72 mV,and 6.25 mV under load conditions.Meanwhile,the frequency band 0 to 50 Hz of the PB's IEMF spectrum shows obvious fractional characteristic harmonics,and their amplitudes increase with the fault level.According to the 5% elasticity margin,the fault detection thresholds under no-load/load conditions are set to 9.83% and 11.49%,respectively,which are 4.56% and 0.82% different from the minimum values of 14.39% and 12.31% in the 2 turns-ITSC states,so that the ITI defects can be identified accurately. Experiments on the synchronous generator show that the peak time-domain values of the PB's IEMF corresponding to the faulty pole decrease with the increase of ITSC degree.The peak values of the time domain corresponding to normal,2.6%-ITSC,5%-ITSC,and 7.3%-ITSC under no-load conditions are 120.07 mV,115.43 mV,112.24 mV,and 109.05 mV,respectively.In contrast,2.4%-ITSC,4.5%-ITSC,and 6.6%-ITSC under load conditions are 133.99 mV,130.22 mV,128.76 mV,and 125.58 mV,respectively.According to the PB's IEMF spectrum,there are obvious fractional characteristic harmonics in the 0-50 Hz frequency band.Their amplitudes increase with the ITSC degree,and the amplitude of 50 Hz fundamental frequency decreases slightly.In addition,the PB's IEMF information for 10 electrical cycles under no-load/load conditions is randomly selected for calculating the HARs.Considering the 5% elasticity margin,the fault detection thresholds under no-load/load conditions are set to 1.27% and 1.39%,which are 1.74% and 3.14% different from the minimum values of 3.01% and 4.53% in the ITSC state.Therefore,the threshold method can be used to achieve the target defense of ITSC fault. In conclusion,the HAR threshold detection method is proposed by analyzing and mining the IEMF's time/frequency domain characteristic information of PB.The proposed method verifies finite element modeling calculation of in-service PSM and the measurement of the synchronous generator,providing a non-intrusive on-line monitoring method for the on-site operation and maintenance.关键词
抽水蓄能电机/转子绕组/匝间短路/定位筋感应电动势/谐波幅值比阈值检测法Key words
Pumped storage motors/rotor winding/inter-turn short circuit/induced electromotive force of the positioning bar/harmonic amplitude ratio threshold detection method分类
信息技术与安全科学引用本文复制引用
齐鹏,李永刚,马明晗..抽水蓄能电机转子匝间短路无传感器检测方法[J].电工技术学报,2024,39(20):6431-6443,13.基金项目
国家自然科学基金(51777075)和国家自然科学基金青年科学基金(52307053)资助项目. （51777075）
