An improved test bench for phase-leg based on IEGT 3L-NPC inverter

Abstract

Three-level neutral point clamped (3L-NPC) phase-leg, as the core component of the inverter, directly determines its performance. The design scheme of 3L-NPC is considered through simulations and calculations. To research and evaluate the characteristic of the designed phase-leg further on the basis of injection-enhanced gate transistors (IEGTs), a test bench of 3L-NPC is developed via an FPGA-based control system and graphical user interface (GUI). A test bench, which can easily assess the feasibility of the design configuration, is provided. Moreover, a test method is presented in this paper to simulate the real operating mode and evaluate the electrical effect of the phase-leg for the 3L-NPC inverter. This method effectively provides test results through full-power device action and measurement. Furthermore, the test bench provides effective means for testing the phase-leg, which is of theoretical and realistic significance to the design of a reliable 3L-NPC.