Research On Modeling And Simulation Of Using Battery Energy Storage To Improve Grid Capability Of Accessing Photovoltaic Power

Grid capability of accessing photovoltaic (PV) power is the main factor restricting the development of photovoltaic industry, and using battery energy storage is one of the effective means to solve the bottleneck problem. Wide attention has been paid to this field, and establishing complete models of Photovoltaic Power System (PVPS) and Battery Energy Storage System (BESS) is the basis of carrying out related studies.In current domestic power system analysis software, the PVPS model cannot accurately reflect actual grid-connected features, and the BESS model cannot satisfy the need of grid-connected analysis. This paper focuses on building more complete models of PVPS and BESS, and the main work and contributions are as follows:(1) The principle and modeling technology of PVPS is studied. Depending on actual grid-connected characteristics, the electromechanical transient model of PVPS is established, with functions of reactive power regulation, active power control during failure and recovery period and Low Voltage Ride Through (LVRT). Based on Power System Analysis Software Package (PSASP), the validity of the model is verified by simulation and test data comparison.(2) The principle and modeling technology of BESS is studied. With the purpose of realizing grid-connected control strategies, the power flow model and the electromechanical transient model of BESS are established, which can fully represent the positive role BESS plays in the steady and transient state. Based on PSASP, the validity of the models is verified by characteristic analysis.(3) Models of PVPS and BESS are applied to actual project background, and preliminary grid-connected analysis is carried out. All kinds of disturbances and system failures are set, and BESS are installed with different capacity, locations and control strategies. By studying the different control effects of BESS on improving grid capability of accessing PV power, important performance parameters of BESS are put forward. At the same time, the validity of the models and simulation methods is further verified.Thesis results can provide more complete simulation tools for related researches of PVPS and BESS. On this basis, further studies can be carried out on precise modeling of BESS, coordinated control and capacity configuration of multi-type energy storage system, etc.