双PWM变换器功率前馈控制策略仿真研究

双PWM变换器常规直接功率控制结构下直流母线电压波动幅度较大,威胁系统的安全运行。为减小直流母线电压波动,根据瞬时有功功率平衡关系,提出一种功率前馈控制策略,即通过构建负载状态前馈通道,将电机侧瞬时有功功率直接前馈于网侧瞬时有功功率给定,从而避开了相对缓慢的电压外环间接调整功率的过程,大大加快了系统的响应速度,有效地抑制了直流母线电压的波动,进而可以减小中间电容的容量及系统的体积和成本。仿真结果验证了控制策略的有效性。

Simulation Research of Dual-PWM Converter Based on Power Feedforward Control Strategy

The larger DC-bus voltage fluctuation of the dual-PWM converter under the conventional direct power control(DPC) strategy threatens the safe operation of the system.In order to reduce the fluctuation,a power feedforward control strategy was proposed according to the instantaneous active power balance.In this strategy,the motor-side instantaneous active power was directly fed-forward to the grid-side given instantaneous active power node through a constructed load state feedforward channel,which avoided the slower process of indirect power adjustment through outer voltage loop.So,the system response speed was greatly accelerated,and the DC-bus voltage fluctuation was inhibited effectively.Furthermore,due to the smaller fluctuation of the DC-bus voltage in the proposed strategy,the capacitance of the DC-bus capacitor could be reduced,which also contributed to the smaller volume and lower cost of the system.Simulation results demonstrate the effectiveness of the proposed strategy.