| With the continuous development of renewable energy,the traditional AC power distribution network is not enough to connect large-scale distributed equipment.In this context,because the energy router can not only realize the flexible interconnection between AC-DC power distribution networks,but also monitor the real-time electrical data of each port,it has attracted the attention of academia and the industry.It has shown good application prospects in providing flexible interfaces for renewable energy,energy storage systems and electric vehicles.In traditional energy routers,the energy storage unit mainly realizes the storage and transfer of energy by controlling the charging and discharging of the battery.When connected to the distributed energy or load,it will still have a large impact on the grid,resulting in a decrease in the bus voltage.Fluctuations are very detrimental to the life of the battery itself.To this end,this paper introduces the super capacitor energy storage system,takes the hybrid energy storage type energy router as the research focus,and conducts research on its topology and the control strategy of the AC/DC interface converter.The main research contents are as follows:This article first proposes the topology of an energy router with a hybrid energy storage system,and studies its topology.After comparing and analyzing the characteristics of power-type and energy-type energy storage media,lead-acid batteries and supercapacitors are finally selected to form a hybrid storage with high power density,high energy density,high environmental friendliness,and long-term recycling.Can system.The characteristics of the above two energy storage media were further analyzed,and the active structure of the hybrid energy storage system and the DC bus was selected.This solution can greatly improve the charging and discharging characteristics of the energy storage media and effectively improve the endurance of the hybrid energy storage system.The two energy storage methods are modeled and corresponding control strategies are proposed.After that,in order to fully meet the multi-port requirements of the energy router and realize the coordinated control of the energy of each access port,the photovoltaic,DC load and AC inverter units of the energy router are modeled and analyzed.Among them,the virtual synchronous generator(Virtual Synchronous Generator,VSG)on the AC side about the basic structure and mathematical model of Synchronous Generator are introduced in detail,and the VSG control strategy is simulated and verified by building a system model in the MATLAB simulation platform.Then compare the DC-port DC/DC converter and AC VSG control to get the virtual DC motor control model.By controlling the on and off of the DC/DC chopper,the control goal of system DC bus stability is achieved,so that the DC bus voltage has certain inertia and damping characteristics.The overall model of photovoltaic,energy storage and load is built in the MATLAB simulation platform to simulate and verify the proposed control strategy,which verifies the effectiveness of the proposed control technology in improving the dynamic stability of the DC bus voltage.Finally,the power distribution strategy of the hybrid energy storage unit and the power control strategy of the energy router system are designed,and the working state and output of the photovoltaic and energy storage unit are determined through the operation state,so as to realize the balanced flow of power.And through simulation in Matlab/Simulink,the correctness and effectiveness of the proposed control strategy are verified.Figures[Sixty-two]Tables[Four]References[Seventy-two]... |
PDF Full Text Request