부산대학교 도서관

A bidirectional AC/DC converter based on an AC system is typically used to build a DC microgrid. Therefore, the DC output impedance is critical to the operation and stability analysis of the micro-grid. This article proposes a VSM control strategy with DC droop, and uses the upper-level power command to achieve non-differential DC voltage regulation. An analysis of the interaction between active power transmission, active power command, and DC voltage is then conducted using a small signal model. Furthermore, the DC output impedance model of the converter controlled by the DC droop VSM strategy is established, and the influence of key parameters such as damping and inertia coefficient, DC side capacitance, transmission power, and DC droop coefficient on the DC output impedance is further analyzed in detail. Finally, he correctness and effectiveness of DC droop VSM control strategy are verified by simulation results and impedance measurements.