Semiconductor Devices Condition Monitoring Using Harmonics in Inverter Control Variables

The health status of power semiconductor devices in power converters is important but difficult to monitor. This paper analyzes the relationship between harmonics in inverter control variables and a health precursor (the on-state voltage Von of power semiconductor devices). Based on the analysis, harmonics can estimate Von without adding extra sensing circuits. The method is validated through simulations.

Introduction

Power electronic-based converters are used in a wide range of applications including electric vehicle powertrains, aerospace power supplies, distributed generation systems, etc. Besides high power density and efficiency, reliability is a main concern of power converters since it affects the system performance and cost. The abnormal states of inverters is the highest (43%) among all the other devices leading to 36% lost productivity in photovoltaic (PV) systems [1]. Power converters also contribute to 13% of failures over different subsystems and 18% of downtime in wind turbines [2].