高灵敏度储能电容器直流局部放电测试分析系统

直流局部放电测试能有效判断高压储能电容器的绝缘性能状态.对于较大容量的高压储能电容器,要求研制具有高灵敏度的测试分析系统.系统的测试部分由并联RLC型电桥平衡回路.窄带、增益稳定的放大单元和带通滤波器构成,具有信噪比高、抑制干扰能力强的特点.通过触发采集方式将提取到的直流局部放电信号送入计算机,并基于△t(相邻两脉冲的时间间隔)对数据进行处理,以统计分析谱图形式反映局部放电信号的特征参数.经过标准脉冲发生器校验,测试分析系统的灵敏度可达2 pC.基于该测试分析系统,对具有典型缺陷的高压储能电容器进行直流局部放电测试,测试结果有效反映了局部放电参量之间的关系,为故障类型识别、老化程度评估奠定基础.

High sensitive DCPD measuring and analysis system of high voltage storage capacitor on high voltage storage capacitors

DCPD(Direct Current Partial Discharge) detection is used to estimate the insulation condition of high voltage storage capacitors.For the capacitors with large capacitance,DCPD measuring and analysis system with high sensitivity should be applied.Its measuring section is composed of balanced RLC detection circuit,stable narrowband amplifier and band -pass filters,with higher signal -noise ratio and better disturbance suppression capability.PD signals acquired in trigger mode are extracted and loaded into computer,which are processed by delta(t) analysis.Their characteristics are displayed in statistical spectrums.It has high sensitivity of 2 pC,verified by standard impulse generator.The high voltage storage capacitors with typical defects are tested by the system to set up the relationships between DCPD characteristics and faults,which are the basis of the fault type identification and aging degree estimation of capacitors.