Identificaion Modeling Method of Voltage Frequency Response Model for Microgrid in Islanded Mode

Voltage and frequency response model of microgrid system is an indispensable and key tool for designing secondary voltage frequency controller and analyzing voltage frequency stability of microgrid system. However, it is very laborious to build up the microgrid system model by mechanism modeling owing to the difficulty of obtaining the distributed generation (DG) model caused by the widespread use of commercial power supplies and other factors. If we adopt the method of identification modeling and regard the microgrid as a whole, we can see it as a black-box system with dual-input and dual-output, and the black-box identification modeling can be carried out only through the power reference data of the input port and the voltage and frequency data of the output port. At the same time, the recursive damped least squares method is used in model identification, so that online identification can be achieved. Simulation and experimental results show that, the proposed model can accurately reflect the voltage and frequency response characteristics of microgrid, thus verifying the validity of the proposed black-box identification modeling method.