An engineering design of a 2MW direct-drive permanent-magnet wind-power generation system

With rapid development of the power semiconductor devices, direct-drive permanent magnet synchronous generator (PMSG) has shown the significant advantages for its high efficiency, reliability, and becomes an attractive choice for variable-speed wind power generation. MW class PMSG system with larger capacity, higher power density is an important trend. This paper describes the engineering design of the domestic first 2MW direct-drive PMSG system, including optimal machine design, converter topology choosing and its control. The generator injects the power to the grid through two fully controlled back-to-back PWM converters that are parallel connected as master-slave structure. A load current sharing control strategy is presented for the parallel connection. Some experimental results are given to illustrate the performance of the actual system.