A Control Strategy for Voltage Source Inverter adapted to Multi - mode Operation in Microgrid

The technology of microgrid has been developed by the progress of new energy technology, the new energy connected to the microgrid by (distributed generator) DG. Microgrid represents the new direction of the power grid as the great complements of traditional power supply network. This paper presents that using several photovoltaic grid-connected inverters as the DG, and control the microgrid by controlling the inverter. The control methods of inverters are P/Q control, v/f control and droop control, because there don't need communication among the inverters when using the droop control, so it has higher reliability. This paper using the droop control, and introduced virtual impedance, realize the microgrid system can operate normally with the load when the microgrid system suddenly break off from the grid, and ensure the system can switch, when connecting to the grid current source and switch to the voltage source. Finally it verifies the feasibility of the control method by using building the simulation in Simulink.