电能表中互感器角差的纠错算法

Error Correction Methods for Phase-Shift of Transducer in Electric Energy Meters

提出了一种电流互感器和电压互感器角差补偿的新算法。深入研究和分析了具有电感和电阻的电流互感器和电压互感器的等值电路,在实际测量应用中人为地造成一个RL电路的暂态过程,采用数字微分算法能够快速准确地算出RL电路的频率和时间常数,进而计算出电流互感器和电压互感器的角差。提出了电能表中补偿电流互感器和电压互感器角差的有功功率和无功功率计算方法。仿真结果表明,该算法能大大地提高电能表的计量精度。

An error correction algorithm for phase-shift of current transducers(CT) and potential transducers(PT) in electric energy meters is presented in this paper. The equivalent circuits of CTs and PTs with inductances and resistances are also studied. In the actual application systems of measurement, a transient process is created in a RL circuit, and then the frequency and time constant of RL circuits can be accurately estimated using numerical differentiation methods. With the measured frequency and time constant, the phase-shift angle of CTs and PTs can be estimated. An algorithm for computing active and reactive power which is used to compensate the phase-shift angle of CTs and PTs is presented. In a study example simulated in an electric energy meter, the proposed algorithm shows higher accuracy and less time requirement.