Control Law Design of a Low-power Wind Energy System Using Active Speed Stall Techniques

Abstract

This paper deals with power control structure design for low power fixed-pitch wind energy conversion systems (WECS) operating in large wind speed variation range. By using variable-speed operation capability, this structure achieves both output power maximization in partial-load regime and power limitation in full-load regime, in this latter case by using active speed stall technique. This control must ensure good dynamic performance in both regimes, as well as smooth transition between them, provided that such transition is accompanied by control phase reversal and also by important plant model changes. This paper proposes a comprehensive design approach of the respective power controllers and an original switching mechanism ensuring smooth transition. The experimental results performed on a dedicated test rig show good dynamic performance, being obtained regardless of the wind speed and the operating regime.