Modelling and Evaluation of Thermal Performance of Rotor-side Converters of DFIG Wind Turbines

This paper presents thermal characteristics of rotor-side converter (RSC) in doubly-fed induction generator (DFIG) wind turbines (WTs). A numerical power loss and thermal model simulator has been developed to obtain instantaneous junction temperature of power devices for a wide operating range of RSCs. Thermal performance of four RSC candidates, including Si IGBT based 2L / 3L-NPC / 3L-ANPC RSCs and SiC MOSFET based 2L RSC, are analyzed and evaluated. The results show that Si 3L-ANPC RSC and SiC 2L RSC achieve superior thermal performance compared to traditional Si 2L and 3L-NPC RSCs, thus leading to improved power density, lifetime and reliability of RSCs in DFIG WTs.