Analysis of Acoustic Noise and Vibration of PMSM Coupled with DC Generator for Electric Vehicle Applications

In recent years, the market of the brushless Permanent Magnet (PM) motors, such as Permanent Magnet Synchronous Motor (PMSM) and Brushless Direct Current Motor (BLDCM) drives, has become huge due to demand of the Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs). However, brushless PM drives are less robust compared to other types of motor drives due to the high acoustic noise, vibrations, and de-magnetization risk of the PM (Chan. Proc IEEE 95:704–718, 2007; Report, Implementing Agreement for Co-operation on Hybrid and Electric Vehicle Technologies and Programmed. International Energy Agency, 2016). These shortcomings pose important restrictions for critical applications. Initially, to run PMSM, Sinusoidal Pulse Width Modulation (SPWM) is implemented. But this technique generates current harmonics and high torque ripples, which ultimately leads to Acoustic Noise and Vibration (ANV) in PMSM drive. Hence, for analysis purpose, a framework based on lumped model along with effective mass and mass participation factor technique for prediction of torsional vibration in case of SPWM technique is elaborated to show detailed methodology for vibration response caused by high torque ripples. This framework is generalized in a way that can be easily extended to any mechanical power transmission system having shaft-coupler or geared system especially for EV and HEV application. Also, vibration prediction modelling is integrated with optimum number of modes or degree of freedom selection technique, which help to enhance the accuracy of model along with computationally efficient, which is the novelty of present work, which usually researchers took earlier randomly based on their setup and mass distribution without any specific technical justification. The vibration analysis reveals high torsional twisting and untwisting of shaft in case of SPWM, because of high source torque ripple. Henceforth, a Random Pulse Width Modulation (RPWM) technique for reduction of ANV is discussed in this chapter. The proposed RPWM method brings a significant reduction in torque ripples which directly influence ANV in the motor, thereby enhancing the performance of the complete drive system under operation. The relationships between the stator current harmonics feed by drive and non-sinusoidal magnetic field flux distribution, with torque ripples is developed and detailed analysis is discussed in this chapter. An extensive simulation and experimental work are carried out on a 1.07- kW, 4-poles, 36-slots, 3-phase PMSM drive for validation of proposed control strategy. In the end, experimental validation part is presented for all analytical modelling and simulation results presented in this chapter.