基于无电网电压传感器的Vienna整流器滑模模型预测控制

Sliding mode predictive control of Vienna rectifier based on grid voltage sensorless

Vienna整流器的控制系统设计与电网电压参数密不可分,然而,传统的电压传感器增加了系统的成本和复杂性.针对此问题,提出一种Vienna整流器无电网电压传感器模型预测控制策略.通过建立Vienna整流器虚拟磁通数学模型来估计电网电压,利用二阶低通滤波器消除了积分初值和直流偏置问题,进而提高观测效果.其次,结合模型预测直接功率控制(DPMPC),以功率跟踪误差最小为目标得到三桥臂的开关序列.实验结果表明,所提出的控制策略谐波含量低,电压能准确跟踪给定值,具有良好的稳态和动态性能.

The control system design of the Vienna rectifier is inseparable from the parameters of grid voltage.However,conventional voltage sensors increase the cost and complexity of the system.Therefore,a model predictive control strategy for the Vienna rectifier without a grid voltage sensor is proposed in this paper.First,the mathematical model of virtual flux for the Vienna rectifier was established to estimate the power grid voltage.A second-order low-pass filter was adopted to eliminate the initial integral value and DC bias problem,which in turn improved the observation effect.Secondly,combined with the direct power mode predictive control(DPMPC),the switching sequence of the three-bridge arm was obtained to minimize the power tracking error.The results show that the proposed control strategy has low harmonic content.The voltage can accurately track the given value.It has good steady-state and dynamic performance.