薄弱电网下新能源设备并网锁相同步方式综述

Overview of phase-locked synchronization methods of renewable energy equipment in weak and distorted grid

随着风能与光伏等新能源的广泛应用,为实现新能源设备的稳定并网运行与精准功率控制,需要在控制中加入锁相同步环节获取准确的电网相角信息。当新能源设备接入薄弱电网时,常规锁相同步方式往往不能达到理想的锁相同步效果。为此,首先阐述了常规锁相同步方式的结构及建模;然后针对新能源设备接入薄弱电网时,常规锁相同步方式不能适应不对称及谐波、频率相位突变与低短路比的运行环境,需要对常规锁相同步方式进行优化设计,分别对上述运行环境下的改进型锁相同步方式进行分析;最后指出了薄弱电网下改进型锁相同步方式的发展方向,即需要研究低短路比电网下的参数设计方法以及提高多场景薄弱电网下的运行性能,为后续相关研究提供参考。

Wind power and photovoltaic have been widely employed,in order to achieve the stable gridconnected operation and precise power control of renewable energy equipment,it is necessary to add phaselocked synchronization link to obtain accurate grid phase angle information.When renewable energy equip⁃ment is connected to a weak and distorted power grid,conventional phase-locked synchronization methods often fail to achieve ideal phase-locked synchronization effect.For this reason,firstly the structure and modeling of conventional phase-locked synchronization methods are described.Then,when the renewable energy equipment is connected to a weak and distorted power grid,the conventional phase-locked synchronization methods cannot adapt the operating environment of unbalance,harmonics,sudden changes in frequency or phase,and low short circuit ratio,so it is necessary to optimize the design of the conventional phase-locked synchronization structure,and analyze the improved phase-locked synchronization method under the above operating environment respectively.Finally,the development direction of the improved phase-locked synchro⁃nization methods in the weak and distorted grid is pointed out,such as the parameter design method under low short circuit ratio power grid and optimization of operating performance in weak and distorted grid under multiple scenarios,which provides a reference for subsequent related research.