A Modified Modulation Scheme for T-type Traction Inverters to Enhance Low-Speed Range Efficiency in Electric Vehicles

In this paper, a modified three-level Space Vector Modulation (SVM) technique is proposed to increase the inverter's efficiency at low-speed operation in Electric Vehicles (EVs). Thus, an efficiency-optimized operation for the whole speed range is achieved; an industry stumble is solved. The control modification allows the efficiency optimization without the need to add/modify to the high cost power circuit of the inverter. The proposed modulation technique is applied to a three-level T-type Neutral Point-Clamped (T-NPC) topology. Based on the results achieved in this study, the proposed modulation technique improves the efficiency compared with the typical three-level SVM and the two-level six switches conventional inverters. The design, simulation, and experimental results are given in the paper to prove the merits of the proposed control scheme.