Abstract:
The power electronic DC microgrid lacks inertia, and when the power fluctuates, the DC bus voltage will have a large mutation, which is not conducive to its stable operation. In order to solve this problem, virtual DC motor control is applied to the DC converter to simulate the external characteristics of a DC motor, so as to provide inertia support for the DC microgrid. However, the traditional fixed parameter virtual DC motor control will sacrifice the dynamic response speed of the system while providing inertia. To solve this problem, a parameter adaptive virtual DC motor control is proposed and applied to the push-pull DC/DC converter at the energy storage unit. A small signal model of the system is established, the influence of the change of moment of inertia parameters on the system is analyzed, and the adaptive adjustment principle of parameters is given. Finally, a simulation model is built to compare and analyze different control methods. Simulation results show that the proposed control strategy not only provides large inertial support for the system, but also has fast dynamic response.This work is supported by the National Natural Science Foundation of China(No. 51877187).