Power Management Strategies of a DC-Coupled Hybrid Power System in a Microgrid for Decentralized Generation

A classical wind energy conversion system is usually a passive generator. Its power does not depend on the grid requirement, but entirely on the fluctuant wind condition. In this paper a DC-coupled wind/hydrogen/super-capacitor hybrid power system is studied. The purpose of the control system is to coordinate these different sources, especially their power exchange, in order to make the generated power smooth and controllable. As results, an active wind generator can be built to provide some ancillary services to the grid. For that, the control system should be adapted to integrate the power management strategies. Two power management strategies are presented and compared experimentally. We found that the "power dispatching" strategy has better performances on the grid power regulation than the "grid following" strategy.