基于复数滤波器的电网电压同步技术

电网正序电压矢量角是可再生能源发电系统能够正常接入电网所需具备的最基本也是最重要的信息,锁相环是得到此信息的有效方式。该文首先分析锁相环的基本原理,然后分析锁相环的改进方式,根据分析结果提出两相静止坐标系下的改进复数滤波器的锁相环。通过仿真验证改进复数滤波器能够快速准确地分离出电网三相电压的正负序分量,并能够在一定程度上对电网电压的谐波进行衰减。

The positive-sequence voltage vector angle of the power grid is the most basic and important information required for a renewable energy power generation system to normally connect to the power grid.The phase-locked loop is an effective way to obtain this information.This paper first analyzes the basic principle of the phase-locked loop,and then analyzes the improvement method of the phase-locked loop(PLL).Based on the analysis results,a phase-locked loop with an improved complex filter in a two-phase static coordinate system is proposed.Simulation results verify that the improved complex filter can quickly and accurately separate the positive and negative sequence components of the three-phase voltage of the power grid,and can attenuate the harmonics of the power grid voltage to a certain extent.