Simulation Of Micro-grid Operation

With the rapid development of the world industry and economy, the energy crisis is showing before the humans.Meanwhile, the malpractice of super large-scale power system appears increasingly, and the vulnerability of the grid has been fully exposed. Based on this, the distributed generation technology--micro grid with renewable energy as the main energy has got the fast development. The characteristic of the micro-grid is small investment, flexible power, and compatible environment. It has brought great changes to modern power system operation and control.As an effective supplement to the grid and an effective utilization form of distributed energy, the micro-grid coordinates the contradiction between the large grid and distributed generators, and it has changed the single power supply pattern and improved power supply reliability and efficiency greatly.According to the internal structure and output voltage characteristics of the solar pool panels, this paper establishes the PV (Photovoltaic) array power system simulation model,which adopts the incremental conductance method to realize the MPPT (Maximum Power Point Tracking),and uses grid voltage oriented vector control method to realize the double control for DC voltage and AC, and then achieves grid by three-phase voltage PWM (Pulse Width Modulation) inverter. In actual environment, the temperature and light intensity are both changed, so during the simulation we should considering different external conditions for PV array power system with load capacity. The energy of PV array power system has non storage, so we preliminary study the charge-discharge properties of battery and simulate for it, and make it as an effective complement for PV array power system, then enhance operation stability and efficiency for the power system.Wind power is the most important development form for current new energy, this paper establishes a simulation model of wind turbine by analyzing the working principle and characteristics of wind turbine, also analysis the characteristics of off-network operation and on-network for wind turbine when the external condition as wind speed,load and so on change; on the basic of Wind power system, combining it with the PV array power system and battery establishes micro grid simulation model, and simulates for the operation situation of micro-grid power system when the external condition (temperature,light intensity,wind speed) changed and sudden events(micro power fault,load changed) happened in grid operation.This paper studies on simulation modeling and operation situation of micro grid and micro power, and establishes two common micro power simulation model, and analysis the operation characteristics of off-network and on-network, at the same time establishes a micro grid power system simulation model including the two micro power, and simulates for it, and gets some simulation data which offers data support to practical application of micro grid power supply system, so the study has some practical application values.