The Research On Micro-Grid Model And Electromagnetic Transient Simulation

With the problems of centralized power supply system is increasingly clear，more andmore people pay attention on the study of distributed power generation technology.Distributed generation technologies have the characteristics of small investment、shortconstruction period、clean and green， etc. In order to solve the problem of distributedpower generation access to network，to maximize the use of new energy，it is proposed theconcept of micro-grid.Micro-grid combined a variety of distributed generation、energystorage and load Organically，have flexible operation mode，high power supply reliability.Micro-grid is one of the main trends of power system development in the future.Micro-grid distributed power systems include Micro combustion turbine、 windgenerators、 photovoltaic power generation systems， its operating characteristics is veryComplicated，and most of them access to grid through the inverter；micro-grid connect tonetwork through static switch，both can run independently，also and run with the network;Therefore，establish a detailed and accurate simulation model is very important to studymicro-grid’s operating characteristics. Frist， This paper describes the storage-typedouble-fed induction wind generation、photovoltaic cells、lead-acid battery simulationmodel， then simulation and analysis the Micro-grid operating characteristics.First，the paper analyze the ordinary double-fed wind turbine basic working principleand control strategy，and improved the double-fed wind generators，add storage equipmentbetween the two PWM converters，to achieve the active power and reactive powerdecoupling control，at the same time，add the crowbar circuit to rotor-side converter，reducing fault current that flow into the rotor-side converter，while maintaining the DCbus voltage stability；Secondly， the paper analyze the engineering practical mathematical modelphotovoltaic cell，and build a photovoltaic cell simulation model with FORTAN，and verify the output characteristics of photovoltaic cells，and use the Incremental conductanceMethod to achieve MPPT control，the model achieves maximum power tracking；Again，the battery storage and its control principle was explored，and establishthird-order nonlinear dynamic equivalent circuit model to verify the validity of the model；Finally，built the micro-grid model on the PSCAD，the model contain double-fedinduction wind turbines、solar photovoltaic cells and lead-acid battery，and verify themicro-network stability under all operating environment；...