This paper presents reliability analysis of the power electronic converters for grid-connected permanent magnet generator-based small 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. Based on the statistics, converter component failure rate of the unified calculation model is established. The power loss model presented 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. It is shown that the inverter has the dominant effect on the system reliability for the converters. The reliability and service life of four kinds of electronic converters are compared through field data, which prove that theoretical analysis is correct.