Simulation Research On Technology Of Hybrid Energy Storage And Photovoltaic Systems Interface To Microgrid

With increasingly issues of environmental problem and severe shortages of fossilfuels, photovoltaic and other renewable energy applications can be decentralized willplay an important role in people’s lives. But with environmental changes, photovoltaichas intermittent and randomness, it causes the problem of photovoltaic microgridsystem power quality and impact grid, so need to configure the storage system tomaintain system stability. Nowadays, suitable for microgrid energy storage batteriesmany types, but there are some limitations or deficiency, so consider environmentallyfriendly lead-acid battery energy and long cycle life power super capacitor energycombined into a hybrid-type storage system.This paper first introduces the basic principles and mathematical models ofphotovoltaic power generation system, choose to use the ideal model of PVgrid-connected inverter, and summarize the structure and operation of microgrid.Then focus on the energy storage system, including principles and models of batteriesand supercapacitor, for each charge and discharge characteristics simulation analysis.Established by the active power converter connected in parallel hybrid storagearchitecture, to optimize battery operation, and improve the utilization of the energysystem. According to construction of hybrid energy storage system, further designcontrol strategy of bi-directional DC/DC converters and bidirectional DC/AC inverterto control the hybrid energy storage system.On the basis of deeply analysis of the characteristics of photovoltaic and energystorage and hybrid energy storage system control strategy, based on the typicalmicrogrid structure, in MTLAB/Simulink platform to build photovoltaic energystorage microgrid dynamic simulation model, battery and hybrid energy storage betransient simulation compared to verify the advantages of hybrid energy storage. Thenin the grid and microgrid island operation, to the situation of light intensity changesand load changes are simulated analysis，and get variation of microgrid voltage andfrequency to verify the effectiveness of the hybrid energy storage control strategy.Simulation results show that hybrid energy storage for the system to quickly provideactive and reactive support, and ensure that the system voltage and frequency stability.For the future applications promotion, through practical case for micro-griddemonstration project including energy storage system economics is analyzed.