三相逆变器并联的模型预测直接磁链控制

Model Predictive Direct Flux Control of Parallel Three-phase Inverters

针对传统的PQ下垂控制存在频率和电压降落等问题,引入虚拟磁链,对有功功率分配采用相角下垂控制,无功功率采用磁链下垂控制,并将下垂控制与三相逆变器的模型预测控制相结合,利用模型预测直接磁链控制,对下垂控制器输出的参考磁链和相角进行跟踪控制,该方法无需PI调节器和脉宽调制器,不仅能够实现各并联逆变器对负载功率的精确分配,提高系统的频率特性,而且显著改善了逆变器并联系统的动态特性。仿真和实验验证了所提方法的正确性和可行性。

Aiming at the problems of conventional droop method,such as frequency and voltage deviations,virtual flux was introduced to the droop controller.The active power and the reactive power were allocated by drooping the phase angle and virtual flux respectively,moreover,the droop control and the model predictive control of the three?phase inverter were combined,and the output reference flux and phase of the droop controller were tracked by the model predictive direct flux contro(l MPDFC)which avoided the use of PI controllers and PWM modulators.While the load power between parallel inverters could be divided equally,and the frequency characteristics of the system was improved and the dynamic characteristics of parallel inverter system was improved significantly.The proposed method is verified by simulation and experiment.