基于电热耦合模型的风电变流器IGBT结温特性研究

Reseerch of IGBT Junction Temperature Characteristics Based on the Electro-thermal Coupling Model

随着我国新能源电力的规模化开发,新能源发电系统(包括风电、光伏、生物质能、海浪等)装机容量不断增长,对新能源变流器的容量、效率和可靠性的要求也越来越高。研究风电变流器IGBT的结温有助于研究变流器的可靠性,为新能源安全运行提供了支持。目前,针对IGBT结温的计算主要是基于数据手册,损耗计算采用了热路模型或者场的方法,并且忽略了恶劣的运行环境以及IGBT不同工况故障带来的影响。针对其在不同运行工况下的结温特性问题,建立了IGBT功率模块的电热耦合模型,分析了在SPWM控制策略下IGBT功率模块结温特性的变化规律。仿真结果表明,在电网遇到的三相故障短路问题、开路问题以及高海拔地区风机恶劣的运行环境影响下,对IGBT的结温都会有很大的影响。

With scale development of new energy power,capacity installed in new energy power generationsystems,including wind,solar,biomass,waves,etc.is increasing.It requires higher converter capacity,efficiency,andreliability of new energy.Research on wind power inverter IGBT junction temperature helps to study the reliability ofthe converter and to provide support for the safe operation of the new energy.At present,the calculation of IGBTjunction temperature is based on data book,the loss calculation uses the thermal path model or the field method,andthe influence of the bad operating environment and the IGBT of different operating conditions is neglected.Thechange rule of power module IGBT junction temperature characteristics under the SPWM control strategy was analyzed.Simulation results show that the three phase short circuit in the power grid problems,open issues and the high altitudefan under the influence of bad running environment have great influence on the IGBT junction temperature.