Analysis of Radial Force Ripple with Sensor Errors and its Effect in NVH Performance for SRMs

Phase current shaping is a common approach to reduce the radial force ripple and thus improve the noise, vibration, and harshness (NVH) performance of the switched reluctance machine (SRM). However, this method is reliant on the accuracy of the position and the current sensors. This paper presents an analytical approach to model the effect of position and current sensor errors on radial force ripple SRM and its impact on the NVH performance of the machine. As a phase current shaping method, current harmonics injection is chosen to analyze the sensor errors on its performance. Initially, the radial force is modelled using the Fourier series expansion. Then, position and current sensor errors in the SRM drive system are included in the analytical modelling. The harmonic orders of the radial force ripple are analyzed and simulated for different sensor errors. NVH performance of SRM is analyzed to show the effects of different sensor errors on the current profiling methods. Simulation and experimental results are provided to verify the proposed method of analysis.