Abstract:
The increasing penetration of new energy sources and power electronic equipment has caused problems such as insufficient inertia and decreased stability of new power systems. In this paper, a model prediction double-loop coptimisation(MPDC) control strategy based on a virtual synchronous generator(VSG) is proposed as an example for the grid-connected photovoltaic storage integrated machine. In the power outer loop, model predictive control is used to correct the VSG reference power at different stages according to the synchronous generator rotor frequency characteristics.For the inner loop, a finite set three vector model predictive current control(FCS-TV-MPCC) is selected to achieve accurate tracking of the outer loop output reference voltage. Simulation and experiment show that the proposed control strategy can improve the frequency tracking accuracy, and compared with the traditional control method, it can reduce the system frequency overshoot in the case of sudden change of load. At the same time, it reduces the frequency change rate,so as to improve the active frequency modulation characteristics.