Motor harmonic current detection system based on magnetic sensor

摘要

In order to obtain the motor current signal conveniently and solve the problem caused by the fundamental frequency fluctuation of the power network, a current harmonic detection system based on magnetic sensor is proposed in this paper. This system will simplify the measurement process, as it uses the magnetic sensor instead of the traditional current transformer to obtain harmonic current waveform. In order to improve the calculation accuracy, the window function and interpolation algorithm is used in the detection system to correct the result calculated by Fast Fourier Transform, which can depression the disturbance of asynchronous sampling and non-integral period truncation. Test results show that the measurement error of frequency and the relative error of amplitude is small, which can prove that the proposed system is simple and effective.