Study On Control Strategy Of Smooth Switching For Micro-grid Based On Master-slave Structure

With the development of economy, non-renewable energy shortage and the environmental pollution and ecological destruction caused intense attention to social, the transformation of the renewable energy sources such as wind and solar energy use technology to get fast development. Micro-grid as a new network topology, it can effectively reduce the distributed mass into energy generated by power grid volatility. Mode control strategy and control structure of micro-grid in grid connected and islanded operation are different, when micro grid switch, due to two mode controller status does not match, the output of the controller will jump.Therefore, this paper was based on master-slave structure of micro-grid to study micro-grid operation control strategy, at the grid connected mode, the master control inverter with the improved PR control to increase the control precision of the system, at the island model, the master control inverter using a micro-grid voltage and frequency variation based droop coefficient adaptive control improved droop control strategy, makes system when switching power gaps to greatly reduce the influence of voltage and frequency, on the basis, focused the studied on the micro-grid when switching between two modes of control, this paper presents a method of adjusting the adaptive droop coefficient and the output of the controller state synchronization control for micro-grid smooth switching control strategy.Master-slave structure of micro-grid was finally set up in Simulink is analyzed, the simulation results verify the grid-connection control strategy and the island control strategy and smooth switching control strategy of this paper are effectiveness, meet the requirement of system stable operation of control.