Autori: N.A. Cutululis, H. Bindner, I. Munteanu, A. Bratcu, E. Ceanga, P. Soerensen

Editorial: European Wind Energy Conference, 2006.

Rezumat:

Wind – diesel power systems represent a viable solution for rural electrification. One of the most important aspects taken into account for the design of a wind – diesel power system is the wind power penetration, which is defined as the ratio between the amount of energy obtained from the wind turbine and the primary electrical load. However, the penetration of wind power into small diesel-based grids is limited because of its effect on power quality and reliability. Hence, a wind power system with a control strategy that allows a trade-off between wind energy extraction and minimization of the induction generator torque variations is well suited for operating in small wind – diesel power systems. The antagonistic demands of optimum wind power extraction and power quality can be achieved with appropriate control of the electrical generator torque.
This paper considers the case of a variable speed wind turbine with focus on the operating range below rated speed. An optimal control loop for the wind power system is designed. The optimality of the whole system is defined in relation with the trade-off between the wind energy conversion maximization and the minimization of the asynchronous generator torque variation that is responsible for the frequency fluctuations. This is achieved by using a combined optimization criterion, resulting in a LQ tracking problem with an infinite horizon and a measurable exogenous variable (wind speed). The solution of the optimal control problem is presented. The performances of the optimal control structure are assessed and discussed by means of a set of simulations.

Cuvinte cheie: Windmills, optimal control, diesel generators, optimal control