三相电压型PWM整流器双开关表控制

A Control Strategy of Three-phase Voltage PWM Rectifier Based on Double Switching Table

通过仿真分析了传统直接功率控制(DPC)系统的原理及性能,发现传统DPC采用一个开关表同时控制瞬时有功、无功功率,负载扰动时功率和直流电压出现了较大波动,电流畸变严重。为改善此情况,在Matlab/Simulink环境下搭建了基于双开关表DPC系统的仿真模型,并与传统的开关表控制进行比较。仿真结果表明,通过单独控制有功和无功功率作用时间(开关表信号的占空比),改善了对无功、有功功率的调节能力,系统控制性能得到了提高,最后通过实验验证了双开关表控制策略的可行性。

This paper analyses the principle and properties of the direct power conrol （DPC） system for present three- phase Boost type PWM rectifiers based on its Simulink model.Switching table controls instantaneous active power and reactive power,leading to the fluctuation of power and direct current voltage during load current disturbance.In order to improve the control of the system, in Matlab/Simulink environment, a new DPC system simulation model is built, with the traditional switching table is compared.Simulation results show that the new DPC system has an good control capability of the active and reactive power based on alternating use of instantaneous active power and reactive power switching tables.Meanwhile ,the new control strategy is proved feasible by experiments.