改进型混合PLL在矩阵整流器中的应用

摘要

分析了矩阵整流器的数字控制策略,针对电网三相不平衡时相位难以准确锁定的问题,基于两相静止α,β坐标系锁相环(PLL)技术,提出一种能够分离并跟踪两相静止α,β坐标系下网侧电压正序分量的改进型PLL算法,即延时信号消除αβ-PLL(DSC-αβ-PLL).通过详细的理论分析和公式推导,结合仿真及实验对所提改进型PLL应用于矩阵整流器进行了验证.结果表明,该技术能够使矩阵整流器在三相不平衡故障下稳定、快速地跟踪并锁定电网的相位和频率信息,实现单位功率因数.%The digital control strategy of matrix rectifier is analyzed.An improved phase-locked loop(PLL) is proposed which is referred to as delay signal cancelled αβ-PLL(DSC-αβ-PLL) based on the stationary α,β references frame PLL.The DSC αβ-PLL can separate and track the positive sequence voltage component of the grid side in the stationary α,β references frame.Through the detailed theoretical analysis,combined with simulation and experiment,the modified PLL is applied to the matrix rectifier.The results show that the phase and frequency information of the grid can be tracked and locked stably and quickly under the three-phase unbalance fault and the matrix rectifier can realize the unity power factor.