Investigation of Three-level Dual Output T-type NPC for EV Application

The use of inverter in drive train is becoming popular in medium to high power EV applications. Special purpose EVs such as four wheel drive SUVs and all-terrain electric vehicles (ATVs) use multiple motors in their drive train system. Thus, a multi-output inverter with multilevel topology can be employed to decrease the cost and increase the reliability. The traction motors used in EV application need to be controlled in closed loop fashion in order to obtain better dynamic response. In this paper, a three-level dual output voltage (TL-DOV) inverter is presented, that can independently control two three-phase motors in closed loop. The TL-DOV can generate low-ripple current waveforms with controllable amplitude, frequency and phases. The disadvantage of requiring multiple DC sources is also mitigated. Field-oriented control is implemented to control the speed % torque of the permanent magnet synchronous motor (PMSM). The performance of TL-DOV is compared with a conventional NPC using MATLAB\Simulink.