电流互感器铁心饱和引起二次电流畸变的补偿研究

Research on Compensation of the Distortion in Secondary Current Caused by TA Saturation

电流互感器(TA)铁心饱和将引起二次电流发生畸变,对此,该文提出一种新的补偿方法。新方法采用TA二次绕组感应电压和二次电流波形的奇异性特征检测饱和的开始和结束,并通过适当延时检测结果来确定铁心不饱和时段。在铁心不饱和时段,通过定义新的目标函数并引入实时最小二乘算法来估计一次电流参数;在铁心饱和时段和铁心饱和状态发生变化的过渡时段,则以参数估计结果求取二次电流的补偿值。该方法具有补偿精度高、便于实时实现等特点。仿真分析表明,该方法适用范围广,能够在含有噪声的环境下正常工作。实验结果进一步验证了该方法的实用性。

This paper proposes a new method to compensate the distortion in secondary current caused by TA saturation. The method detects the beginnings and ends of saturation by singular characters of waveforms of secondary induction voltage and current, and determines precisely the time sections in which TA is not saturated by delaying the detection result. When TA is not saturated, the method uses Real-time Least Square （RLS） algorithm to estimate parameters of primary current, and in the other time, the method compensates distortion of secondary current with the estimation results of primary current parameters. This method can get high precision and is very fitful of real-time implementation. Simulation and experiment show that the method can be used widely, is immune to noise and has good practicality.