基于模型预测控制的机侧变流器功率模块结温波动抑制策略

JUNCTION TEMPERATURE FLUCTUATION SUPPRESSION STRATEGY FOR POWER MODULE OF ROTOR-SIDE CONVERTER BASED ON MODEL PREDICTIVE CONTROL

针对双馈风电机组运行在同步转速点附近时,低输出频率使机侧变流器功率模块承受较大结温波动,致使变流器可靠性降低的问题,提出一种结温波动抑制的模型预测控制(MPC)策略。首先,基于双馈感应电机电压和磁链方程,推导功率预测控制模型;其次,构建基于机组最大功率跟踪(MPPT)的目标函数;然后,搭建基于MPC的双馈风电机组电热仿真模型,时域分析机组在亚/超同步工况下往复运行时机侧变流器功率模块的动态/稳态结温波动;最后,对比现有结温波动抑制策略,验证所提控制策略的有效性。

When the doubly-fed wind turbine operates near the synchronous speed point,the low output frequency makes the power module of the rotor-side converter suffer from large junction temperature fluctuation,resulting in reduced reliability of the converter,In order to solve the problem,a junction temperature fluctuation suppression strategy,based on model predictive control(MPC),is proposed.Firstly,the power predictive control model is derived based on the voltage and flux equations of doubly-fed induction generator.Secondly,the objective function is deduced to achieve the maximum power point tracking(MPPT).Then,an electro-thermal simulation model of doubly-fed wind turbine based on MPC strategy is built.The dynamic and steady-state junction temperature fluctuations of the power module,during the reciprocating operation under sub-/and super-synchronous conditions,are analyzed in time domain analysis.Finally,the effectiveness of the proposed control strategy is verified by comparing with the existing suppression strategy of junction temperature fluctuation.