多局部放电源的电/电磁波和声信号时序分析

局部放电既产生瞬态的电/电磁波信号,也辐射声波,为了解决设备内多局部放电源的存在给诊断所带来的困难,通过对局部放电辐射的电脉冲、电磁波和声波检测信号的分析,忽略脉冲信号的幅度特性和持续时间,仅考虑脉冲接收的起始时间点,构成对应的布尔量时间序列,以分别代表局部放电的电/电磁波和声波的布尔量时间序列,为两个坐标轴建立直角双时间坐标系。理论分析认为,任何一个局部放电源的电/电磁波和声波的布尔量时间序列在该坐标系下构成一条45°直线,不同局部放电源因时延的不同形成的直线位置不同。实验研究工频下不同位置的3个局部放电模型的放电时序关系及由它们的电/电磁波和声波布尔量时间序列建立的直角坐标系的结果表明,该法有可能识别多局部放电源,重构各局部放电源的放电时序关系,藉此研究各放电源的相间局部放电谱图及其放电模式变迁,并获得用于局部放电定位的关键参数超声波传输时延。该法物理意义明确、应用简单。

Time Sequences Analysis of Electric/Electromagnetic and Acoustic Signal Emitted from Multiple Partial Discharges

By analyzing the time sequences of electric and electromagnetic and acoustic signal emitted from PDs,ignoring pulse signals' amplitude and duration time,and only considering their reception time start-points,Boolean variable time sequences are built and a double-time right-angle co-ordinate system is also built up where the two axial respectively describe the Boolean variable time sequences of electric/electromagnetic and acoustic pulse.Analysis indicates that the Boolean variable time sequences of electric/electromagnetic and acoustic pulses of each PD source can be fitted into a line with the slope of 45 degree,and different PD sources usually form different lines because of different time delays.Discharge experiments on 3 PD models in different positions are carried out to verify this method.The research indicates that,this simple and clear physical meaning method has the possibility to recognize multiple PD sources,reconstruct the discharges' time sequences and PRPD diagram respectively,and acquire the vital travel time delay of acoustic wave of each source which is used in PD localization.