基于半导体功率损耗的小型风电变换器可靠性研究

摘要

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.%基于半导体功率损耗,针对小型风电永磁电机常用的Boost(Intermediate boost converter, IBC)、Buck-boost (Intermediate buck-boost converter,IBBC)、背靠背(Back-to-back converter, BBC)、矩阵(Matrix converter, MC)变换器可靠性进行分析,确定变换器在特定风速下的失效周期和可靠性.在统计学基础上,建立了变换器元件的故障率统一计算模型.通过计算电力电子器件的开关损耗和导通损耗,确定 Boost变换器相对其他变换器具有最高的失效周期.同时确定出变换器组件中,逆变器可靠性是影响变换器可靠性最重要的因素.通过现场数据比较四种变换器可靠性和使用寿命,证明理论分析是正确的.