Research on Improved Active Damping Method Based on Dc Microgrid

Abstract

In order to solve the system instability caused by a large number of constant power load access in the DC microgrid, an active damping control method based on the DC current feed forward of the grid connected converter is proposed. The mathematical model of DC-AC converter and the control strategy of active damping method suitable for DC-AC converter are studied in this paper, and a small signal mathematical model of DC microgrid is established. Based on the principle of system dominant pole distribution and impedance matching, the adverse effects of constant power load on the stability of the system and the improvement of the active damping method on the stability of the system are analyzed, and the design principle of the active damping parameters is given. Simulation and experimental results show that the proposed active damping method can improve the stability of DC microgrid system with constant power load and high permeability.