Parameter control strategy of DC microgrid based on interconnected converter control

Abstract

Microgrid makes full use of distributed energy, reduces energy consumption, and effectively exerts the advantages of distributed generation. Aiming at the problem that the interconnected converter is easily affected by the intermittence and disturbance of new energy sources when operating, the internal electronic devices of the system have small damping inertia and weak immunity. A control strategy with a "power-voltage-current" three-loop structure is designed for the interconnected converter. The active power reference value is generated by the bidirectional droop control, and the damping and inertia of the active power are improved by using the VSG characteristics. At the same time, the small-signal modeling and stability analysis of the "active power-frequency" control based on VSG characteristics is carried out. Through the simulation, the power mutual support between sub-microgrids and the power dynamic balance of the whole system are realized to ensure the stable and reliable operation of the system. Then the feasibility and practicability of the control strategy are verified, which provides a theoretical basis for future research on the coordinated control strategy of the microgrid.