| Abstract |
A modular-multilevel (MMC) DC/DC converter is proposed in this paper, which can be deployed to inter-connect DC grid of different voltage levels, especially in the new energy sources such as wind power and solar power grid connection. Its key features include: 1) step-up and step-down operation. 2) bi-directional power flowing. 3) bi-directional fault blocking similar to a DC breaker. The operation principle of DC/DC MMC is analyzed, and a control strategy is proposed to ensure power balance of every sub module capacitor. Simulations are performed with Matlab-Simulik to validate the principle of operation and the proposed control strategy. |
