Inverse-System Control Approac

This paper presents an inverse-system control approach for Variable-Speed Variable-Pitch Wind Generator Systems (VSVP-WGS) in order to optimize the wind energy conversion in a high wind speed region. The controller synthesizes the ideas of two-time-scale approach and inverse-system method. Based on two-time-scale analysis, the model of VSVP-WGS can be reduced to a first-order one with non-affine and nonlinear characteristics. With
inverse-system method, the nonlinear model is converted into a pseudo-linear one and then can be stabilized simply by linear system approach. The performance of the inverse-system controller (ISC), which is confirmed through theory analyses and simulations, show that, compared with a proportional-integral controller (PIC), it makes VSVP-WGS provide a wider operating region and generate smoother output power. Compared with other nonlinear controllers, ISC is simpler and can be more easily transplanted to other kinds of WGS.Index Terms: wind generator system, pitch control, non-affine system control and inverse-system control