景旭,孙岩洲,宋晓燕.高频信号注入法测量配电网电容电流及滤波的研究[J].电测与仪表,2016,53(24):. Jing Xu,Sun Yanzhou,Song Xiaoyan.The research of signal injection method with high frequency for distribution network capacitive current measurement and filtering[J].Electrical Measurement & Instrumentation,2016,53(24):.
高频信号注入法测量配电网电容电流及滤波的研究
The research of signal injection method with high frequency for distribution network capacitive current measurement and filtering
To solve the problems such as frequency selection and power frequency interference of the injection signal method to measure the capacitance current, this paper analyzes and improves the method of high frequency signal injection. Inductance value by injecting 5000Hz high frequency signals obtained first, then through the frequency sweep method to determine the resonance frequency of the power grid and calculate the distribution of capacitance current value, and by using the method of series capacitor to reduce the capacitance of big earth capacitance system, to realize accurate measuring capacitance current. At the same time, using the digital signal processor TMS320F28335 and the finite impulse response (FIR) filter algorithm to realize filtering function, filter the power frequency interference signals when frequency sweeping. Through theoretical analysis and experimental verification, this method can increase the range of capacitance measurement, simplify the calculation, filter the power frequency signal, the relative error of the measurement are less than 5%.
