A Gate Driving Strategy for the Series-Connected IGBTs to Improve the Resilience Against IGBTs Short-Circuit Failures
Sadegh Mohsenzade
Abstract
The application of series-connected insulated gate bipolar transistors (IGBTs) is becoming widespread in high-voltage/power converters. The reliable operation of the resulted series high-voltage switch (RSHVS) is of considerable importance. This article investigates the effect of the IGBTs single short-circuit failure on the performance of RSHVS. It will be revealed that the gate drive system dedicated to command the series-connected IGBTs has the main role in spreading these prevail failures to the others. Consequently, the operation of RSHVS is interrupted in such common failures. Hence, extant gate drive systems are very fragile against this type of failure. To overcome this issue, this article proposes a gate drive system with resilience against IGBTs short-circuit failure. The proposed gate drive system does not spread the single failures to the other healthy IGBTs. Thereby, the interrupted operation of RSHVS as well as the cascaded failure in the whole of IGBTs are avoided. Results indicate at least 40% improvement in the meantime to failure of RSHVS with respect to the extant strategies. In addition, the power loss should be accepted for the safe voltage condition of IGBTs decreased considerably in the proposed approach. The performance of the proposed approach is evaluated using simulations and experiments.