Publications Repository - Gdańsk University of Technology

Given the recent available IGBT switch modules up to 6.5 kV, 1200 A rating, the prospect of the diode-free variant topology of the three-level neutral-point-clamped (3-level, T-type) inverter in certain medium voltage applications is bright; due to its small part count and low conduction losses compared to the diode-clamped NPC inverter. However, within this voltage range, the input dc voltage rating of 50% of the switches per inverter phase-leg still poses limitations to the deployment of 3-level T-type inverter. In view of these limitations, a reconfigured four-switch per phase-leg power circuit for 3-level inverter (F-type) is presented in this paper. The common node of the bidirectional switch in T-type inverter is explored to have only one power switch rated at input dc voltage and 3 switches rated at half the input dc voltage, per inverter-leg. This reduced voltage stress has inverter cost and loss implications. The performances and competitiveness of the three-level, F-type inverter are analyzed in detail and demonstrated with a hardware prototype. Results reveal that it has the potentials of being considered a real alternative to 3-level, T-type inverters for certain low- and medium-voltage applications.

Authors

• Charles Odeh,
• dr hab. inż. Arkadiusz Lewicki link open in new tab ,
• prof. dr hab. inż. Marcin Morawiec link open in new tab ,
• mgr inż. Dmytro Kondratenko link open in new tab