一种基于三端口网络的互感器电压串联加法

1954年Zin E和Forger K成功研究出互感器串并联电压加法线路;1988年国家高电压计量站成功研究出互感器双边串联电压加法线路,2006年使用串联型电压互感器进行双边电压加法,2008年试验电压达到1000/3kV,电压比不确定度不大于4×10^-5(P=95%)。要进一步减小电压比的不确定度,需要最大限度地消除串联型电压互感器的屏蔽误差以及邻近干扰误差。除了设计电磁屏蔽更完善的串联型电压互感器外,还可以使用三端口网络理论实施电压加法,通过三端口网络的响应叠加性,使得在加法过程中的屏蔽误差和邻近干扰误差很大程度上得到补偿。2013年使用广东电网电力科学研究院的500kV工频电压比例自校系统装置进行了验证试验。与1988年数据相比,110/3kV电压下的屏蔽误差从18×10^-6减小到1.5×10^-6,与2006年数据相比,500/3kV电压比例不确定度从15×10^-6减小到7×10^-6(P=95%)。

A Transformer Voltage Series Method Based on Three-Port Network

In 1954 Zinn E and Forger K researched series-parallel voltage summation circuit by employing voltage transformers successfully. In 1988 the National High Voltage Metering Station studied the bilateral series voltage summation circuit successfully. In 2006 the National High Voltage Metering Station employed series type voltage transformer for bilateral voltage summation. In 2008 the test voltage reached 1000/3kV and the uncertainty of voltage ratios was not more than 4×10^{-5(P=95%). In order to reduce the uncertainty of voltage ratio, it is necessary to eliminate the shielding error and proximity interference of the series type voltage transformer. In addition to design a series type voltage transformer with more perfect shielding structure for electromagnetic interference, the theory of three-port network could also be used to implement voltage summation. Following a certain test procedure the shielding error and proximity interference in the summation operation would be largely compensated by the response superposition of the three-port network. In 2013, the 500kV power frequency voltage proportional self calibration system of Guangdong Electric Power Research Institute was used for verification test. Compared with the data in 1988, the shielding error at 110/3kVdecreased from 18×10-6 to 1.5×10-6, and compared with the data in 2006 the uncertainty of ratio error at 500/3kV decreased from 15×10-6 to 7×10-6(P=95%).}