改进无差拍控制策略的仿真分析

Simulation analysis of improved deadbeat control strategy

针对延时问题带给级联H桥SVG的差一拍问题,提出了一种在dq坐标系下实施的改进离散无差拍控制方法。为减小延时,提前观测下一拍指令电流,改变了常规电流状态观测器的结构,预先计算设置中间变量。同时为了提高输出电压的预测精度,为此采用了重复控制预测算法。最后为了证明改进无差拍控制方法的可行性和优越性,运用MATLAB完成了仿真验证,结果表明:改进的无差拍控制算法可以有效提高系统的动态和稳态性能,除掉了系统的跟踪滞后问题,减小了系统的输出电压误差,补偿效果更加明显。

In view of the delay problem,a modified discrete deadbeat control method was proposed in the dq coordinate system for the differential beat problem of cascaded H bridge SVG.In order to reduce the delay and observe in advance the next shot instruction current,the structure of the conventional current observer was changed,and the intermediate variables were precalculated.Meanwhile,in order to improve the prediction accuracy of output voltage,repetitive control prediction algorithm was adopted.Finally,in order to prove the feasibility and superiority of the improved deadbeat control method,the MATLAB simulation experiment was carried out.The results showed that the improved deadbeat control algorithm could effectively improve the dynamic and steady performance of the system,eliminate the tracking lag problem of the system and reduce the output voltage error caused by the capacitance voltage of the DC side,and the compensation effect was more obvious.