A Novel Control Scheme for Traction Inverters in Electric Vehicles With an Optimal Efficiency Across the Entire Speed Range

Abstract

In the context of the electric vehicle (EV) industry, multi-level inverters (MLIs) have garnered increasing attention due to their potential to harness the advantages of higher DC link voltages. Among the various MLIs, the three-level T-type neutral-point-clamped (T-NPC) topology stands out as a superior alternative to the conventional two-level six-switch counterpart. This paper presents an adaptive Space Vector Modulation (SVM) technique for the typical three-level T-NPC inverter, with the aim of enhancing inverter performance across a wide speed spectrum in EVs. Through a comprehensive process of design, simulation, and experimental analysis, the findings reveal improvements in efficiency when compared to both the two-level six-switch inverter and the T-NPC inverter employing conventional three-level SVM. These results underscore the advantages and effectiveness of the introduced control scheme, which increases efficiency without incurring additional costs of any additional circuit components or control effort. The paper provides a complete set of in-agreement simulation and experimental results, to provide the proof of concept.

Keywords

• T-NPC inverter
• SVM
• low-speed range analysis
• PMSM