Application-Oriented Flexible Power Cycling Test System for Power Electronic Components

Power cycling tests are crucial for assessing the packaging-related reliability performance of power electronic components. This paper presents a versatile test system designed for both DC and AC power cycling, aimed at evaluating the reliability of power devices under realistic stress conditions. Initially, the paper details the system's design—from PCB layout to software control—and outlines the considerations taken during its development to inspire practicing engineers and promote discussions on standardization specific to AC power cycling. Focusing on on-state voltage and junction temperature as the primary ageing parameters, the paper discusses the on-state voltage measurement circuit and validates its effectiveness and accuracy with measurements from high-voltage optically isolated probes. It subsequently emphasizes the implementation of optical fibers for direct junction temperature measurements, followed by a comparative analysis of this method's measurement accuracy against the traditional $V_{CE}$(T) method. Lastly, the paper presents and evaluates power cycling test results for both DC and AC modes, demonstrating the effectiveness of the proposed design.