Reliability comparison of power electronic converters for grid-connected 1.5kW wind energy conversion system

This work presents reliability analysis of the power electronic converters for grid-connected permanent magnet generator-based 1.5 kW wind energy conversion system based on the semiconductor 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 is developed and used to generate power for different wind speeds. Afterwards, a relation between the wind speed 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 efficiency and MTBF of an IBC are 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.

► A reliability comparison of four grid connected converters is presented.
► Switching and conduction losses of converters are determined for each converters.
► Intermediate boost converter has greater MTBF than any other inverters.
► Determining the least reliable subsystem of converters is proposed and verified.