并网逆变器三矢量模型预测电流控制

The Predictive Current Control of Three Vector Model of Grid-connected Inverter

三相并网逆变器的双矢量模型预测电流控制克服了传统单矢量模型预测控制电流脉动大、电压矢量方向固定、寻优次数少、稳态性能差等缺点,具有较好的控制效果。但该方法只能控制交轴电流,直轴上的电流脉动依旧很大。在双矢量控制算法的基础上提出了一种三矢量模型预测电流控制,即把一个控制周期分给2个非零电压矢量和一个零电压矢量来控制并网逆变器。三矢量模型预测控制采用了交直轴无差拍方式来计算各个电压矢量的作用时间,对交直轴上的电流分量同时实现了预测控制,从而有效减小了电流脉动,使系统的动态和稳态性能更为出色。最后,对传统的单矢量、双矢量和提出的三矢量模型预测控制进行实验和仿真。结果表明:三矢量模型预测控制更为高效,电流脉动更小,谐波含量更少,鲁棒性更强,具有很好的应用前景。可为多矢量模型预测控制在并网逆变器上的应用提供参考。

The two-vector model predictive current control of three-phase grid-connected inverter overcomes the disadvantages of traditional single vector model such as large current pulsation,fixed voltage vector direction,few times of optimization and poor steady-state performance.But this control only controls the alternating current,the current pulse on the straight axis is still large.In view of the limitation of this control,a three-vector model predictive current control is proposed based on the twovector control algorithm,that is,a control period is divided into two non-zero voltage vectors and one zero voltage vector to control the grid-connected inverter.The three vector model predictive control adopts the across-axis non-differential beat method to calculate the action time of each voltage vector,and realizes the predictive control of the current component on the across-axis simultaneously,which effectively reduces the current pulsation and makes the dynamic and steady state performance of the system better.Finally,the traditional single vector,double vector and three vector model predictive control are tested and simulated.The results show that the three vector model predictive control is more efficient,the current ripple is smaller,the harmonic content is less,and the robustness is stronger,so it has a good application prospect.This study provides a certain reference value for the application of multi vector model predictive control in grid connected inverter.