Modeling Of Microgrid And Simulation Platform Development

With the intensification of the global energy crisis and continuousenvironmental deteriorate problems, the distributed generation based on renewableenergy technology has developed rapidly in recent years and the microgrid isbecoming a research hotspot. Microgrid as a new type of power system can solve theaccess problem of distributed generation and greatly improves the efficiency of theuse of renewable energy. Microgrid can improve the operation efficiency of thewhole power grid and minish environmental pollution, which is needed by thedevelopment of low carbon economy. The combination of microgrid and grid is away to improve the reliability of power supply and solve the drawbacks oftraditional centralized grid effectively. Microgrid as the effective support of the gridis one of the development trend of the future power grid, which has broadapplication prospects.In recent years, many scholars have done the research of microgrid, but adetailed comparison microgrid simulation model has not been established. In thispaper, based on the Matlab/Simulink simulation software, a microgrid simulationplatform is established for researching dynamic characteristics of a demonstrationproject of microgrid in Beijing. In this platform, the constant power (P/Q) controlstrategy is applied in grid-connected operation and the voltage and frequency (U/f)control strategy based on droop characteristics is applied in isolated operation.Based on the mathematical model and the volt-ampere characteristics ofphotovoltaic cells, the simulation model of photovoltaic cell is established, and onthis basis, the maximum power point tracking (MPPT) module is established basedon the perturbation and observation (P&O) algorithm. From the point of view of thedevelopment and application of microgrid simulation platform, the simulation modelof the lead-acid battery is established on the basis of the research of the batterycharge and discharge characteristics. In consideration of the characteristicsphotovoltaic power generation system of microgrid, the control strategy of inverter isdesigned based on the voltage space vector modulation (SVPWM) method withdouble loop control structure in this paper. The module of U/f control strategy formicrogrid isolated operation is developed based on the droop characteristics ofgenerator.The output characteristics of photovoltaic cells and battery charge anddischarge characteristics are simulated and analyzed, and the effectiveness of the MPPT module is verified in this paper. Finally, based on the microgrid simulationplatform，the characteristics of the microgrid in grid-connected operation mode andisolated operation mode is studied.The microgrid simulation platform set up in this paper can provide solid basisfor further research, which has practical value for the development of microgrid andthe verification of the solution of microgrid.