Characteristics of electronic voltage transformers based on capacitive voltage divider
Zhichao Xu · Dianli zidonghua shebei · 2012
The transfer function model of EVT(Electronic Voltage Transformer based on capacitive voltage divider) is analyzed and deduced.Its frequency characteristics and the transient characteristics of its trapped charge are analyzed.The transient mathematical model of trapped charge is deduced and the parameters which have influences on frequency characteristics and transient characteristics are analyzed mathematically.Simulative results show that,the capacitors of voltage divider and the parameters of integrator have great effects on the frequency characteristics and transient characteristics of EVT.Reducing the integral capacitor or integral feedback resistor may reduce its bandwidth.Reducing the sampling resistor or high-voltage capacitor may increase its bandwidth.Reducing the low-voltage capacitor or sampling resistor may shorten the transient process caused by the trapped charge and then reduce the transient error.