피치 루프 개별 게인 스케줄링 기법을 통한 타워 하중 저감 제어

초록

This paper deals with the NREL(National Renewable Energy Laboratory) 5 MW reference wind turbine for offshore system. The controller which include MPPT(Maximum Power Point Tracking) control to recover the maximum energy from wind and pitch control to limit the power output is applied to wind turbine. Conventional pitch loops have used the same sensitivity scheduling to the P gain signal and I gain signal(CPS, Collective Pitch gain Scheduling). However, this technique only focuses on power control without considering the load on the wind turbine. In addition, the stability of the system can not be guaranteed since the pitch control loop has a low phase margin. Therefore, this paper proposes a technique, which applies gain scheduling individually to the P gain signal and the I gain signal(IPS, Individual Pitch gain Scheduling) for load reduction. To verify the effect, electrical power and tower root moment DEL(Damage Equivalent Load) were set as performance indices. Simulations were performed for 600 seconds under the wind conditions of the normal turbulence model, the turbulence intensity of16 % and the wind speeds of 12~25 m/s. . The proposed IPS technique was found to reduce the fore-aft moment DEL of the tower up to 14.49 % than the existing collective pitch scheduling.

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