基于分数阶滑模控制的直接矩阵变换器控制策略研究

直接矩阵变换器是一个无中间直流环节的AC-AC变换器，但是它和传统的间接矩阵变换器一样，在电网电压不平衡时其输出性能会下降。针对这一问题，提出了一种分数阶滑模控制以改善矩阵变换器的输出性能。首先，分析了矩阵变换器的拓扑结构和数学模型，得到了不平衡电网下的输出功率，并且根据输出功率表达式设计对应的输出补偿。其次，结合控制目标和直接矩阵变换器的数学模型设计出应用于不平衡电网的分数阶滑模控制器。所设计的控制器旨在实现恒定的有功功率，同时以单位功率因数输入。接着，结合输出补偿使输出的有功功率无脉动，同时无功功率能够跟踪参考信号。最后，在Matlab/Simulink和RT-LAB实验平台建立对应模型，验证该算法的有效性。实验结果表明，分数阶滑模控制在控制性能上要明显优于传统PI控制。

Research on fractional-order sliding-mode control of a direct matrix converter

The direct matrix converter is an AC-AC converter with no intermediate DC link. However, like the traditional indirect matrix converter, the predicted performance of matrix converters drastically reduce when operating under unbalanced grid voltages. This paper proposes a fractional-order sliding-mode control to improve the output performance of matrix converters. First, the topology and mathematical model of the matrix converter are analyzed to obtain the output power with an unbalanced grid. The output compensation is designed according to the output power expressions. Secondly, combined with the control objective and the mathematical model of direct matrix converter, a fractional-order sliding-mode control applied to the unbalanced power grid is designed. The designed controller aims to achieve constant active power and input unity power factor. Then, combined with output compensation, the output active power has no pulsation, and the reactive power can track the reference signal. Finally, a corresponding simulation model is established in Matlab/Simulink and RT-LAB experimental platform to verify the effectiveness of the algorithm. The experimental results show that the control performance of the fractional-order sliding-mode control is superior to traditional PI control.This work is supported by the National Natural Science Foundation of China (No. 51777120).