Noise Analysis and Suppression for High Accuracy Current Sampling in Motor Control

High-performance motor control requires high-precision sampling currents, but feedback noise can significantly deteriorate the quality of sampled currents. In this paper, the effect of noise on the current loop is analysed in detail and an effective suppression strategy is proposed. Firstly, the propagation of noise is analysed and modelled, and secondly, the oversampling suppression strategy of traditional SAR ADC is discussed.In addition, the oversampling technique based on the new Sigma delta ADC further improves the sampling accuracy.