Reliability comparison of power electronic converters used in grid-connected wind energy conversion system

Abstract

This work presents a reliability analysis of the power electronic converters for a grid-connected permanent magnet generator-based wind energy conversion system based on the semi conductor power losses. The power converters examined are: the intermediate boost converter (IBC), the intermediate buck-boost converter (IBBC), the back-to-back converter (BBC) and the matrix converter (MC). The aim is to determine which power electronic converter yields the highest mean time between failures (MTBF) and reliability in terms of power losses of the semiconductor devices with a predetermined wind speed. In view of this, a furled wind turbine model developed previously by the author is used to generate power for different wind speeds. Afterwards, a relation between the wind speed, power loss and MTBF is established to evaluate the reliability of the power electronic converters. The power loss model presented in this paper has taken into account the conduction and switching losses of the semiconductor devices within each converter. The analysis reveals that MTBF of an IBC is much higher compared to the other converters considered in this research. The investigation is extended to identify the least reliable component within the converters. It is shown that the inverter has the dominant effect on the system reliability for the converters. This research indicates that IBC with a simple rectifier is a much better option for grid-connected permanent magnet generator based wind energy conversion system.