摘要
为研究重复脉冲电压上升时间对变频电机绝缘的局部放电特征影响规律,基于超高频天线、检波技术和宽带、高速数据采集和传输技术设计了重复脉冲电压下变频电机绝缘局部放电检测系统。研究了变频电机匝间绝缘在不同上升时间重复脉冲电压下的局部放电统计特性并对其机理进行了分析。结果表明:在微秒级的上升时间下,脉冲电压极性快速翻转导致变频电机绝缘薄弱处空间电荷电场和外部电场叠加,易超过局部放电起始电压,从而产生次数较多的小幅值放电,且放电幅值随着上升时间的减小而增大,但单个周期放电总量逐渐减少。因此设计耦合传感器时应根据重复脉冲上升时间和局部放电脉冲频域能量分布特点,设计高频响应较好的传感器,避免脉冲电源干扰使测试灵敏度降低,从而得到准确反映电机绝缘水平的PDIV和RPDIV。
To study the effect of repetitive impulse voltage rise time on the partial discharge（PD） characteristics of inverter-fed motor insulation, we designed a PD detection system for inverter-fed motor insulation under repetitive impulse voltage based on ultra-high frequency antenna, detection technology and broadband, and high-speed data acquisition ＆ transmission technology. The PD statistical characteristics of the interturn insulation of inverter-fed motor under different impulse voltage rise time were obtained by the system, and their mechanism was analyzed. The results show that when the voltage rise time is under μs level, the electric field of space charge of the weak insulation caused by the fast reversal of voltage polarity would superpose the external electric field, which would exceed the partial discharge inception voltage（PDIV） and produce many times of PD with low magnitude. The PD magni- tude increases with the decrease of the rise time, but the total discharge amount in one cycle decreases gradually. Therefore, the design of coupling sensor should base on the repetitive impulse voltage rise time and PD impulse voltage distribution characteristics to avoid the sensitivity decrease disturbed by the pulse voltage, thus the accurate PDIV and RPDIV of the inverted-fed motor were obtained.
出处
《绝缘材料》
CAS
北大核心
2015年第1期53-58,共6页
Insulating Materials
基金
国家自然科学基金青年基金项目(51407121)
