Mitigation and Investigation of NVH Characteristics of Multi-Inverter System on EV Propulsion Motor

The most common method for minimizing vibrations in EV propulsion motors involves an electromagnetic approach aimed at mitigating magnitude of a low order of electromagnetic force. This paper focuses on investigating the characteristics of electromagnetic force orders in propulsion motors operating under both single and multi-inverter systems, through theoretical analysis and finite element analysis (FEA). In a multi-inverter system, adjusting the current phase by ${\mathbf{30}}_e^\circ $ mitigates specific electromagnetic force orders, including (T16, S8), (T24, S0), and (T32, S-8), among others. Consequently, the improved noise, vibration and harshness (NVH) characteristics of EV propulsion motors with a multi-inverter system compared to single-inverter system are demonstrated by coupled-field FEA results.