Proposal of Virtual Transformer-based Back-to-Back Asynchronous Loss Measurement using a Single Set of Measurement Instruments for One Inverter and Experimental Verification

Abstract

In this study, a virtual transformer-based loss measurement method is proposed for inverter power conversion efficiency measurements, and the accuracy of this method is theoretically analyzed. This concept is further extended to a practical measurement procedure, wherein asynchronous loss measurements are conducted for powering and regenerating operations using a single set of measurement instruments. The average efficiency can be obtained with a very high accuracy after calibration of the measurement instruments. A high-efficiency system inverter was selected as the converter under test, and its efficiency and accuracy were experimentally measured and validated. An efficiency of 99.75% ± 0.006% was obtained at an output of 1600 W.