消除直流分量影响和谐波干扰的并网同步方法

在电网发生故障时,如何快速、准确的检测出电网同步信号,对逆变器电力电子控制至关重要。提出了一种基于多重复数滤波器(MCCF)与锁频环(FLL)的电网同步技术,复数滤波器分离出故障电网电压的正负序分量及谐波,锁频环进行电网锁相跟踪,并加入直流分量反馈环节。当电网故障时本文所提结构可以自动地在短时间内准确地跟踪电网电压频率,准确提取故障时电网电压正、负序分量和谐波成分,消除直流分量的影响,且具有较快的动态响应速度.确保并网电力电子器件的稳定、可靠运行。

Grid synchronization method for eliminating DC component and harmonics influence

When the grid fails, how to detect the synchronous signal of the inverter quickly and accurately is essential to power electronic control. A synchronization technology based on a Multiple complex coefficient filter combined with the frequency locked loop is presented in this paper. Multiple complex coefficient filter extracts the positive and negative components of the fault grid voltage, frequency locked loop realizes phase locked and adds the DC component feedback loop. When the grid fails, the proposed structure can track grid voltage frequency automatically and accurately in a short time, extract the positive and negative sequence components and harmonic components, eliminate the influence of the DC component, and has faster dynamic response speed. The stable and reliable operation of the grid power electronics device is ensured.