基于二阶广义积分器的单相并网锁相环的研究

Research on Single-phase Grid-connected Phase Locked Loop Based on Second Order Generalized Integrator

准确快速地追踪电网电压是并网逆变器稳定运行的重要保障,故锁相技术在光伏并网系统中十分重要。常规的过零点电网电压检测锁相方法在面对电压缺相时会使锁相不稳定而失效,甚至会损坏逆变器。针对此问题,提出了基于瞬时无功理论的单相锁相技术,并将该方法应用于单相并网系统,实验验证了该方法的有效性。

Quickly and accurately track the grid voltage is an important guarantee to ensure stable operation of the grid-connected inverter.Therefore,lock-in technique is particularly important in photovohaic grid-connected systems. Conventional lock-in method has zero grid voltage detection,makes voltage phase-locked failure,even damages the inverter.For this problem, single phase lock-in technique based on instantaneous reactive power theory is proposed and this method is applied into single phase grid-connected systems.Experiments verify the effectiveness of the method.