Thermal Characterization of Power Semiconductors with H-Bridge Testing Circuit

Thermal characterization of power semiconductors is becoming crucial for reliability and cost-efficient design of converter. However, the widely used methods which were developed decades ago, have limits in extracting thermal characteristics, especially when considering the dynamic working conditions of the power devices and the emerging needs for the reliability analysis. In this paper, a novel testing method and circuit based on H-bridge topology is proposed. Four sets of IGBTs and freewheeling diodes can be tested under switching conditions at the same time. The heating current can be switched off rapidly to approximate an ideal step power loss. It is demonstrated that the proposed method enables accurate and fast thermal characterization, and the concept has been verified by simulation and experimental results.