配电网过电压在线监测的阻容分压器研制

10kV配电网过电压事故时有发生,但引起的原因难以查明.通常的故障录波器和监测装置大都从电压互感器取样,但由于电压互感器频率响应不够,难以满足捕获大气过电压需要.针对上述问题,设计了用于过电压在线监测用的低阻尼电容分压器.该分压器采用同轴并联结构,通过选取合适的阻尼电阻和电容等参数,获得了良好的冲击响应并有效抑制了波头振荡;采用了有限单元法计算其分布电容参数,并对其误差进行了分析.经实验表明,该分压器具有良好的高低频响应特性和精度,能满足内外过电压监测需要.

Development of Capacitance-Resistance Divider for Monitoring Overvoltage in Power Distribution Network

Accident generated by overvoltage has usually been observed in 10kV power system . However,it is difficult to analyse causes through usual fault oscilloscope or monitoring device. Due to insufficient performance of frequency response of pote ntial transformer, it cannot adapt to need of transforing lighting overvoltage. Accordingly, existing monitoring devices which obtain voltage though transformer generally can not capture lighting overvoltage.Capacitance-resistance divider with excellent performance of frequency response is designed to capture overvolt age ,and it is more suitable than potential transformer to transfer lighting imp ulse overvoltage according to result of square-wave response. Furthermore, Valu e of damping resistor has been considered to suppress oscillating of waveform of impulse. Based on accuracy tests and analysis of finite element, performance of the device for monitoring overvoltage is excellent. The device is significant i n order to on-line monitor overvoltage.