Electric Vehicle Inverter Topologies and Total Harmonic Distortion Mitigation: A Comprehensive Study of Recent Advances and Future Trends

The motor performance, powertrain efficiency, driving range and power quality of an electric vehicle (EV) are greatly affected by the electric vehicle (EV) traction inverter. This paper gives a detailed survey of the inverter topologies and total harmonic distortion (THD) reduction methods published in the literature during the last few years. Conventional two-level voltage-source inverters are compared to multilevel voltage-source inverters, such as neutral-point-clamped, T-type, flying-capacitor, cascaded H-bridge, reduced-switch-count and switched-capacitor topologies, with focus on 400 V and 800 V EV architectures. Other modulation and control techniques like sinusoidal pulse-width modulation, space-vector modulation, selective harmonic elimination, nearest-level control and model-predictive control are also assessed. The results show that the three-level NPC and T-type inverter are very suitable for 800 V systems, which can significantly reduce THD and inverter losses, compared to two-level systems. Moreover, switching performance, efficiency, and power density are enhanced even more by the use of wide-bandgap semiconductors, such as SiC MOSFETs and GaN HEMTs. But harmonic performance is also dependent on the variation in the DC link voltage, dead time effects, motor parameters and operating conditions. Issues of adaptive real-time control, reliability-aware design, fault-tolerant operation, and integrated charger–traction inverter systems should be addressed in future research.