Abstract: Aiming at the issue of microgrid system stability and output consensus， an optimal control method was proposed . The small signal model， coefficient matrix and an incremental perturbation matrix of microgrid system were established， which solved the problem that caused by large computation in the solution of system eigenvalues. On this basis， the objective function of the initial optimization was established by taking the stability， damping ratio and stability margin as the performance indexes. Combining the matrix perturbation theory with the artificial fish swarm algorithm， the initial optimal control of the system was achieved. Meanwhile， in order to ensure the consensus of frequency and voltage of the output of each micro-source in microgrid， the further optimization objective function was established and the artificial fish swarm algorithm was applied a second time for the further optimal control of the system. Finally， the simulation results show that the proposed control strategy is of validity and effectiveness.

Key words: microgrid, small signal model, matrix perturbation theory, eigenvalue of coefficient matrix, optimal control