A New Generalized Integrated Load Model and Its Equivalent Description Based on a Variety of New Energy Loads

Abstract

With the addition of new distributed energy sources, a new and more accurate load model need to be established. Based on MATLAB/Simulink, this paper researches on the modeling and simulating of photovoltaic power generation system and battery energy storage and their equivalent model. First, a detailed model of the photovoltaic system is built. Boost circuit and MPPT control are selected on the DC side of photovoltaic power generation system. The double closed loop control method of current internal loop and external voltage loop is used for grid inverter control. The model is improved considering the capability of LVRT (low voltage ride through). Based on the above precise models, the model is equaled. The equivalent transfer function is calculated by the grid connected control loop, so the model is simplified. The battery energy storage module establishes a general mathematical model based on the charging and discharging principle. Charge and discharge are controlled through the DC/DC converter. And it is connected to the power grid after inverting and filtering. The common PQ control are selected in the inverter control mode. According to the same principle, the energy storage model is equaled. Finally, based on the traditional load model, the above load model is added to set up a new generalized integrated load model. And the actual model is replaced to build up an equivalent model. The equivalent model is compared with the actual model to verify the equivalent description ability.