组合电器电磁式电压互感器低频校验的研究

Low-frequency Calibration for Electromagnetic Voltage Transformer of GIS Combined Electrical Apparatus

分析了组合电器一次回路等值电容对电磁式电压互感器等值电路的影响,提出了校验电磁式互感器低压误差、负荷误差方法,采用低压低频法测量电压互感器的励磁特性经折算至工频励磁特性的计算公式,得到励磁特性非线性数据,最后,结合互感器等值电路计算出互感器在额定电压因数下的误差。其测量结果与常规测量方法得到误差偏差小于0.05%。

This paper analyzes the GIS combined electrical apparatus in terms of its equivalent capacitance in primary circuit and its influence on the equivalent circuit of the electromagnetic voltage transformer. The method is proposed to calibrate the low voltage error and load error of the electromagnetic transformer. The low-voltage and low-frequency method is applied to measure the voltage transformer excitation characteristics, and the calculation formula is derived for converting to the excitation characteristic of power frequency and obtaining the nonlinear data of excitation characteristics. Finally, in combination with transformer equivalent circuit, the error of transformer under rated voltage factor can be calculated. The measurement results by this new method show less than O. 05% deviation from the meas- urement results by conventional method.