Noise Suppression Method of Power Amplifier Current Sensor Based on Adaptive Wavelet

Abstract

The output of the current sensor in active magnetic bearing power amplifier system contains a lot of noise, which will cause the output of the power amplifier to be saturated. Using a traditional second-order low-pass filter to suppress noise will give rise to the phase lag. This paper presents an adaptive wavelet method to suppress the high-frequency noise in current sensor signals. Discrete wavelet transform is applied to estimate the noise of the current sensor, and input the estimated noise into the adaptive filter to suppress correlated components from the reference signal. Theoretical analysis and simulation results show that the noise suppress result of the adaptive wavelet method is better than that of the second order low-pass filter.