面向电流源型PWM整流器的双矢量模型预测直接功率控制

Two-vectors-based Model Prediction Direct Power Control of Current Source PWM Rectifier

电流源型脉宽调制(Pulse width modulation,PWM)整流器因其网侧存在LC滤波器,系统的控制难度增加。传统直接功率控制策略下的整流器功率波形存在脉动,因模型预测控制具有卓越的动态特性以及直观的控制规律,采用模型预测直接功率控制(Model predictive direct power control,MPDPC)对传统控制策略进行改进。首先建立了三相PWM整流器的数学模型,给出了每个采样周期内的功率变化率,并推导出相邻采样周期之间的功率关系,然后给出基于单矢量的模型预测直接功率控制策略,提出了基于双矢量的模型预测直接功率控制策略,并优选出两个电流矢量,计算在一个采样周期内的作用时间,并对其进行修正。最后,在Matlab/Simulink仿真软件验证了所提控制策略的可行性和有效性。

Current source pulse width modulation(PWM)rectifier is difficult to control because of LC filter in its network side.The power waveform of rectifier based the traditional direct power control is pulsatile.Model predictive direct power control(MPDPC)is adopted to improve the traditional control strategy because of its excellent dynamic performances and intuitive control law.Firstly,the mathematical model of three-phase PWM rectifier is established,the power change rate in each sampling period is given,and the power relationship between adjacent sampling periods is derived.Then,single-vector-based model predictive direct power control strategy is given,and two-vectors-based model predictive direct power control strategy is proposed.The two current vectors are optimized,and the acting time in one sampling period is calculated and corrected.Finally,the feasibility and effectiveness of the proposed control strategy are verified by Matlab/Simulink.