非周期分量下电流互感器的相位特性研究

摘要

The non-periodic components of current signal in actual power grid can affect the phase transform characteristic of TA. According to the phase characteristic of TA under non-periodic components, the paper analyzes the TA' s phase characteristic on the basis of the nonlinear time domain equivalent circuit model; at the same time, it builds the model of TA' s phase characteristic model, and also makes use of the software of PSCAD/EMTDC to simulate the characteristic and get the TA's phase characteristic. The simulation result reveals that if there is large non-periodic component in grid, the TA will be transient saturated and the output current will be distortion, the transform phase error increases, which will affect the result of relay protection and electric energy measurement.%实际电网中非周期分量电流的存在,会使得电流互感器的相位传输特性发生改变.针对非周期分量下电流互感器的相位特性,论文以非线性时域等效电路模型为基础,定性分析了在该模型下它的相位特性,同时建立了相位特性模型,并利用暂态仿真软件PSCAD/EMTDC进行了仿真.仿真结果表明:当存在较大非周期分量时,电流互感器出现暂态磁饱和并使得输出电流畸变,相位转换误差急剧增大,造成对继电保护和电能计量的影响.