具有电压自动调整功能的供电型电压互感器误差来源分析及补偿

Error Source Analysis and Compensation of Power Voltage Transformer with Automatic Voltage Regulation Function

为解决供电型电压互感器供电电压随供电负荷波动而变化的问题,设置了辅助互感器串联补偿回路,该回路能够实现对供电电压的自动调节,但会影响电压测量绕组的误差。同时对具有辅助互感器串联补偿回路的供电型电压互感器的误差来源进行了分析,分析结果表明,增加辅助互感器串联补偿回路后,电压测量绕组误差由空载误差、负载误差和辅助回路误差3部分组成。在此基础上对1台容量60 kVA的110 kV供电型电压互感器样机误差进行测量,在负载误差补偿完成后,由于辅助回路分接比变化引起的比值差和相位差的最大变化量达到0.462%和73.14′。通过计算获得了辅助补偿阻抗的数值,并最终实现不同分接比,不同供电负荷容量及功率因数下的误差补偿,补偿后电压测量绕组的误差达到0.2级误差限值要求。该研究实现了对具有电压自动调整功能的供电型电压互感器误差的补偿,使得供电型电压互感器在波动负荷下,同时实现稳定的电压输出和电压计量。

In order to solve the problem that the voltage of a power voltage transformer changes with the fluctuation of the load for the power voltage transformer,a series compensation circuit of the auxiliary transformer is set up,which can realize the automatic regulation of the power supply voltage,but it will affect the error of the measurement voltage.Moreover,the error sources of power voltage transformer with auxiliary transformer series compensation circuit are analyzed.The analysis results show that,after adding series compensation circuit of auxiliary transformer,the error of measurement voltage consists of no-load error,load error,and auxiliary circuit error.On this basis,the error of a sample of 110 kV power voltage transformer with capacity of 60 kVA is measured.After the completion of load error compensation,the maximum variation of ratio error and phase angle error caused by the change of auxiliary circuit tap ratio are 0.462%and 73.14′.Through calculation,the value of auxiliary compensation impedance is obtained,and finally the error compensation under different tap ratios,different load capacities,and power factors is realized.After compensation,the error of the measurement voltage meets the requirements of class 0.2 error limit.The research of this paper realizes the error compensation of the power voltage transformer which has the function with automatic voltage adjustment.Under the condition of fluctuating load,the power voltage transformer can achieve stable voltage output and voltage measurement at the same time.