三相电压源型PWM整流器优化控制策略

Optimal control strategy of three-phase voltage-source PWM rectifier

针对三相电压源型PWM整流器输出电压变化缓慢的特点,提出采用电压电流双闭环控制器,电压外环采用常规PI调节器,电流内环采用电流误差及其变化率作为神经元的输入,实时调整电流PI调节器参数,并采用SVPWM控制方案来提高电流跟踪速度,减小电网输入电流谐波。该控制方案较好地解决了整流器在带逆变器电动机负载时,由于负载工作状态改变而引起的电压、电流扰动问题,提高了响应速度,缩短了响应时间。仿真及实验结果表明,该控制策略能够很好地控制输入电流波形及相位,实现能量的双向流动,达到单位功率因数,具有良好的动静态性能,且算法简单,易于实现。

As the output voltage of three-phase voltage-source PWM rectifier changes slowly,a voltage and current closed-loop controller is proposed. The normal PI adjuster is adopted in the outer voltage loop. The current error and its change rate are used as the inputs of the neural networks in the inner current loop to adjust the parameters of the current PI controller in real time. SVPWM （Space Vector Pulse Width Modulation） is applied to enhance the speed of current tracking and lower the input current harmonics of power network. The strategy better diminishes the voltage and current disturbance caused by the operating mode change of inverter-motor load,elevates the response speed and shortens the response time. The simulative and experimental results show that,the proposed strategy effectively controls the waveform and phase of current,realizes the bidirectional energy flow,achieves the unity power factor and has excellent dynamic and static performances. Its algorithm is easy to implement.