基于反Park变换的不平衡锁相环设计研究

Design of unbalanced phase-locked loop based on inverse Park transform

为实现不平衡电网下正序基波电压相位和幅值的快速、准确获取,文中提出一种基于反Park变换的三相锁相环设计方案。提出一种基于反Park变换的正交信号发生器实现方案;对前述方案进行了详细的数学分析,从理论上证明了所提方案可以有效进行信号正交处理,并给出其关键参数的设计方法;接着,以该正交信号发生器为基础,构建适用于电网不平衡条件下的三相锁相环;通过搭建PSCAD仿真模型在多种电网环境下对文中所设计锁相环进行性能测试,仿真结果表明该锁相环具有良好的适应性,能快速、准确地锁定正序基波电压的相位和幅值。

In order to acquire the voltage phase and amplitude of the positive sequence fundamental wave rapidly and accurately under the unbalanced grid voltage, a design scheme of three-phase phase locked loop based on inverse Park transform is proposed in this paper. Firstly, according to the analysis of the principle of positive and negative sequence voltage separation, a design scheme of orthogonal signal generator based on the inverse Park transform is proposed. Then, the detailed mathematical analysis of the orthogonal signal generator is carried out. It is proved theoretically that the proposed scheme can effectively carry out orthogonal signal processing, and the design method of its key parameters is given. Based on the proposed orthogonal signal generator, a three-phase PLL for unbalanced power grid is designed. Finally, a PSCAD simulation model is built to test the performance of the proposed PLL. The simulation results show that the PLL has good adaptability and can quickly and accurately acquire the phase and amplitude of the positive sequence voltage.