Abstract: The power supply mode of microgrid, which contains a variety of different distributed power sources, is flexible and changeable,and is enough to cope with different working environments through the coordination and cooperation between power sources. Starting from the modeling of different distributed power supply, this paper constructs an appropriate equivalent model based on the basic principles of three distributed power supply: photovoltaic power supply system, battery energy storage system and small diesel power power supply system, and establishes the corresponding grid-connected model and control conversion system according to the respective characteristics and power supply conditions of the three distributed generators. On this basis, a microgrid system including photovoltaic, battery energy storage and diesel generator is constructed. The simulation model of the microgrid was established on the PSCAD platform, and the microgrid was simulated and analyzed under the two working conditions of grid-connected operation and isolated operation, and six different operation modes were proposed, the applicable scenarios of each power supply mode were introduced, and the relevant conditions for the activation and exit of each mode were defined. The simulation results show that the microgrid model with photovoltaic storage diesel can achieve stable and reliable power supply in these six power supply modes.

    Key words: distributed power supply; microgrid ; power supply mode