An Accurate and Simple Electrical Measurement Method to Characterize SiC Module Loss with Synchronous Rectification

Abstract

To measure and characterize power loss and efficiency of highly efficient power semiconductors such as SiC MOSFET modules, a simple and accurate inverter power loss measurement method is proposed. The technique is based on electrical measurement of DC input power and AC output current of an inductor load. High accuracy can be achieved by using low-loss air-core inductor as load. The measurement results are meaningful for SiC inverters in practical conditions operating at synchronous rectification, since the loss is independent on load power factors. The measurement error is minimized because the output real power is designed to be close to the SiC module loss and the Litz-wire air-core inductor avoids the use of complex core loss models. The method is validated for SiC phase-leg inverter. Experimental results are presented and validated on a SiC phase module with 620V DC input and up to 180A output. The inverter loss measurement error is analyzed based on test data.