非线性负荷背景下电流互感器计量特性研究

Research on Measurement Characteristic for Current Transformer under Nonlinear Load Conditions

非线性负荷和电力电子器件的大量使用,导致电网中电压、电流波形畸变越来越严重,不仅存在含有率较大的整数次谐波,而且还存在频谱分量丰富的非整数次谐波(间谐波)。通过搭建好的实验平台,测量了电流互感器在10.0 Hz^2.5 k Hz下的频率特性,同时采用了传递函数的角度从理论上分析了电流互感器的频率特性,实际测量与理论之间很好地相互验证,研究发现,间谐波及高次谐波下,电流互感器的误差都比工频时大;采用实际采集数据分析了谐波负荷下电流互感器对电能计量的影响,发现由电流互感器引入的基波及谐波功率误差相对于其本体的误差都明显增大,而谐波功率误差影响最大至141.799%。

Due to the extensive use of power electronic devices and nonlinear loads,resulting in power grid voltage and current waveform distortion is more and more serious,not only the existence of containing rate larger integer harmonics,but also the existence of abundant spectral components of non integer harmonics,inter harmonics.The built experiment platform,measuring the current transformer in the 10 Hz^2.5 kHz frequency characteristics,at the same time,the transfer function of the angle frequency characteristic of current transformer is analyzed theoretically,between actual measurement and theoretical good mutual authentication,study found that,between harmonic wave and high harmonics,the errors of current transformer are larger than that of frequency.In addition,the use of actual data analysis of the load harmonic current transformer on electric energy metering and analysis,introduced by the current transformer of the fundamental and harmonic power error relative to the current transformer error are significantly increased to 141.799%,and harmonic power error influence.