Abstract
The power output fluctuations of a parallel-variable speed operation system using multiple large-scale wind turbines are numerically analyzed. In this operation, the electric power outputs of load induction generators are connected to one large-capacity PWM converter. The rotational speeds of the wind turbines are synchronized and controlled by the impressed frequency of the converter, and the total power output of the system at high wind speeds is controlled by synchronizing the pitch angle manipulation for all the wind turbines. The numerical analysis conducted by using our dynamic simulation model shows that the parallel-variable speed operation system has a high reduction capability of the power output fluctuations as compared with the separate-variable speed operation system and that the synchronized pitch angle manipulation for all the wind turbines is effective to reduce the power output fluctuations of the parallel-variable speed operation system.
