一种多步预测的变流器有限控制集模型预测控制算法

A Model Predictive Control Scheme of Multi-step Prediction Finite Control Set for Converters

变流器有限控制集模型预测控制(finite control setmodel predictive control,FCS-MPC)算法是一种变流器优化控制算法。该算法具有动态响应快、处理系统约束灵活且无需PWM调制器和相关参数设计等优点,但仅可确保所选开关函数组合在一个控制周期内的最优,这样将使得系统控制趋于保守,而影响系统控制性能。分析传统变流器FCS-MPC算法的保守性,提出一种在一个控制周期内同时考虑最优开关函数组合及次优开关函数组合,并确保在两个控制周期内所选开关函数组合最优的多步预测的FCS-MPC算法(finitecontrol set model predictive control with multi-step prediction,FCS-MPCMSP);进行采用该算法的两电平三相电压型逆变器在空载、带阻感性负载、带非线性负载及负载投入等工况下的仿真和实验。仿真及实验结果表明:采用该算法的三相电压型逆变器输出电压与给定电压的差值明显小于采用传统FCS-MPC算法的情况,改善了逆变器输出电压质量,从而验证了该算法的有效性及可行性。

The finite control set model predictive control（FCS-MPC） scheme is an optimization control scheme for converters,which has the advantages of fast dynamic response,flexibility of control system constraints,and needlessness of pulse width modulation（PWM） modulator and system parameters.This scheme,however,could only make sure the selected switching function set optimize in one control cycle,and will cause the system to be conservative and affect control performance of the system.In this paper,the conservative characters of the traditional FCS-MPC were analyzed,and then a FCS-MPC with multi-step prediction（FCS-MPCMSP） was proposed,in which both the optimal and suboptimal switching function sets were considered in one control cycle,and the selected switching function set was optimal in two control cycles.Then the simulation and experiment on two-level three-phase voltage source inverter controlled by the proposed scheme with the conditions of no load,resistive-inductive load,nonlinear load and load plugging into were done.The results verify that the error between three-phase inverter output voltage and the reference is less than that controlled by the traditional FCS-MPC,and the quality of output voltage of the inverter is improved,so the validity and feasibility of the scheme is validated.