分布式光伏与风电机组LVRT及电流限幅环节的等值建模

Equivalent modeling of LVRT and current limiting links for distributed photovoltaic and wind turbine generators

随着分布式新能源机组的持续并网,电力负荷的动态特性已发生显著变化,需要研究主动配电网等值建模新方法。主动配电网中分布式新能源机组类型呈现多样化,控制器存在切换以及限幅等非线性环节。对此,针对双馈风电机组、直驱永磁风电机组和光伏电源模型结构的共性,构建了可描述多类型分布式新能源机组动态特性的通用模型。在此基础上提出了多激励影响下分布式新能源机组低电压有功管理、低电压无功管理以及电流限幅等非线性环节的非机理等值建模新方法,并基于简单算例进行了验证。对某实际主动配电网进行建模仿真,结果表明:将所提等值模型与传统负荷模型并联,可较为准确地描述计及分布式新能源机组低电压穿越(LVRT)和电流限幅环节的主动配电网的动态特性。

With the increasing integration of distributed new energy units,the dynamic characteristics of power load have significantly changed,it is necessary to study a new equivalent modeling method for active distribution networks.The types of distributed new energy units in the active distribution network are diversified,and the controller has nonlinear links such as switching and limiting.For this reason,with the common characteristics of model structure of doubly-fed induction generator-based wind turbines,direct drive permanent magnet synchronous generator-based wind turbines,and photovoltaic generation,a general model of distributed new energy units is constructed.On this basis,a new non-mechanistic equivalent modeling method for nonlinear links under effect of multi-excitations is proposed,and the results are verified by a simple simulation example.An actual active distribution network is simulated and the results demonstrate that when combines the equivalent model and the classical load model in paralleled,it can accurately describe the dynamic characteristics of the active distribution network considering LVRT(Low Voltage Ride-Through)and current limiting links of the distributed new energy units.