PMSG-Based Dual-Port Wind-Energy Conversion System With Reduced Converter Size

In this study, a dual-port wind-energy conversion system has been proposed. A double-fed permanent-magnet synchronous generator (DFPMSG) forms the central part of the system, where the concentrated single-layer winding configuration of the generator enables electric and magnetic isolation between the ports. DFPMSG has two three-phase terminals out of the stator; one is connected directly to the grid, whereas the other is tied to the grid through a back-to-back converter. This study investigates design issues caused by the DFPMSG port with a direct grid connection. The unique design issues of the proposed system include determining the slot/pole combination using wind data and determining the minimum reactive power requirement for the port with a direct grid connection. Next, the load-sharing capability among the ports of the proposed system is presented through a detailed investigation of three schemes. Experimental work is presented for a 5-kW prototype DFPMSG system to illustrate the isolation among the ports, minimized reactive power demand on the port with direct grid connection, and load-sharing ability among the ports for different control schemes.