消除电压互感器二次回路压降问题的方法

Elimination of secondary loop voltage drops in voltage transformers

为了解决电力系统中电压互感器的二次回路压降问题，提出一种从原理上能够彻底解决该问题的方法。该方法通过将电压互感器的二次输出端电压进行就地数字化处理，并将电信号转换成光信号，采用光纤作为传输媒质将该信息传输至控制室，在控制室再将光信号转变为电信号，供二次电力设备使用。试验结果表明：就地数字化装置在80％～120％额定电压下，比差小于0．01％，角差小于±2′；通过与标准电压互感器的对比试验，验证了该方法的有效性，为解决电压互感器二次回路压降问题提供了一种方法。

The secondary loop voltage drop in a voltage transformer is reduced by converting the secondary output of the voltage transformer to a digital signal using an active electronics circuit located at the secondary interface of the voltage transformer. The signal is then transmitted to the control room through a fiber optic cable with the optical signal that converted back to an electrical signal to the secondary equipment in the substation. Test results show that the locally digitizing process has an error ratio of less then 0.01% and a phase error of less than ± 2′ at 80% - 120% rated voltage, The approach was validated in tests using a standard voltage transformer.