计及虚拟惯量控制与低电压穿越的光伏发电系统暂态稳定分析

为满足光伏发电系统随着装机容量的增加而提出的更高要求,加入了虚拟惯量控制与低电压穿越使系统具备调频与调压的功能。针对计及虚拟惯量控制与低电压穿越的光伏发电系统,建立适用于暂态分析的锁相环扩展非线性模型。基于该模型使用等面积准则的方法分析系统在故障前、故障发生时以及故障切除后的暂态同步过程,从而确定影响系统稳定性的因素。在此基础上,继续使用等面积准则分析电压跌落深度、虚拟惯量控制器参数与锁相环比例、积分系数等因素对光伏暂态稳定性的影响。仿真证明,所提方法可有效分析各种参数对光伏发电系统暂态稳定性的影响,验证了理论分析的正确性。

Transient stability analysis of a photovoltaic generation system considering virtual inertia control and low voltage ride-through

To meet more requirements of a photovoltaic generation system with the increase of installed capacity, virtual inertia control and low voltage ride-through are added to enable the system to have frequency and voltage regulation. Given a photovoltaic generation system with virtual inertia control and low voltage ride-through, an extended nonlinear model of phase locked loop (PLL) is established for transient analysis. Based on the model, an equal area criterion is used to analyze the transient synchronization process of the system before a fault, when a fault occurs and after fault removal, so as to determine the factors affecting system stability. Then the equal area criterion is used to analyze the influence of voltage sag depth, virtual inertia controller parameters, phase locked loop proportional coefficient and integral coefficient on the transient stability of the photovoltaic system. Simulation results show that the proposed method can effectively analyze the influence of various parameters on the synchronization process of a photovoltaic power generation system, and verify the correctness of the theoretical analysis.This work is supported by the Key Project of National Natural Science Foundation of China (No. 51637005).