A Multi-Parameter Rapid Optimization Method of Inverter-Based Microgrid

Abstract

Microgrid is a kind of weak small power network. Because there are a large number of distributed generators in microgrid, it is easy to cause the unstable operation of system. Aiming at the stability issue caused by the change of parameters of many distributed generators in microgrid, a multi-parameter rapid optimization method using matrix perturbation theory is proposed so that the optimization time can be shortened. Firstly, the small signal model of two distributed generators connected in parallel is established. Through the stability analysis, the stability boundaries of the dominant control parameters of distributed generator are obtained. Then the optimization model of microgrid considering the small signal stability, damping ratio and stability margin is established. In order to accelerate the optimization speed and reduce the computational burden caused by the repeated calculation of eigenvalue, a unified equation for the calculation of eigenvalue of proposed system is derived using matrix perturbation theory when the parameters of the power controller, current controller and voltage controller in distributed generator are perturbed. Thus, the small signal stability of microgrid can be improved and the fluctuation of voltage and frequency of microgrid can be reduced. The simulation results show that the fast optimization method based on matrix perturbation theory is feasible.