直流电子式电压互感器延时特性分析与现场测试

Field test and analysis of delay characteristics of a DC electronic voltage transformer

直流电子式电压互感器因受到分压器、远端模块参数改变及合并单元等数字链路因素影响会出现延时,现场准确测试标定该延时特性不易实现。首先,建立了直流电压互感器等效电路模型,分析了直流分压器、低通滤波器等被动元件对直流电子式电压互感器延时时间的影响。在此基础上,提出一种基于暂稳态信号的延时等效测试方法,并研制出直流电压互感器延时特性现场试验系统。通过标准暂稳态信号与被测直流电压互感器的反馈时差精确测量延时时间。最后,采用所提出的试验方案在某直流工程现场进行直流电压互感器延时测试,验证了该方法有效性。

Because of the influence of digital link factors such as the voltage divider, remote module parameter change and merging units, a DC electronic voltage transformer will have time delay. Thus it is difficult to accurately test and calibrate this time delay characteristic on site. First, the equivalent circuit model of a DC voltage transformer is established. Then the influence of passive components such as the DC voltage divider and low-pass filter on the delay time of the transformer is analyzed. Then a delay equivalent test method based on a transient steady state signal is proposed, and a field test system for the transient delay characteristics of the DC voltage transformer is developed. The delay time is accurately measured by the feedback time difference between the standard transient step signal and the measured DC voltage transformer. Finally, using the test scheme proposed, the time delay test is carried out on a DC project site to verify the effectiveness of the method.