Robust H Infinity Control of Micro-Grid to Develop the Power Management Performance

In this paper, to develop the dynamic performance of an islanding mode micro-grid, which contains a wind turbine unit and a gas distributed generation (DG), simultaneous usage of H infinity and robust control are presented. By using the doubly-fed induction generator (DFIG) and the variable speed wind turbine, the system inertia is decreased and then the dynamic stability is also decreased. The virtual inertia implementation in DFIG causes the power system stability improvement. However, the major challenge that should be considered is the change in the system parameters or uncertainties, when the virtual inertia is employed. In this paper, the implementation of virtual inertia in the DFIG control system is described in detail and the impact of uncertainties and changes in the control system parameters over the performance of the frequency control system are investigated. In order to improve the dynamic stability and the steady state performance of the frequency control system, benefiting from the impact of virtual inertia, the mixed robust H infinity control approach is proposed. The simulation results using MATLAB software show that the proposed hybrid controller guarantees system stability in conditions of uncertainties and with the variation of the control system parameters.