The reduction of structural loads is becoming an important objective for the wind turbine control system due to the ever‐increasing specifications/demands on wind turbine rated power and related ...growth of turbine dimensions. Among various control algorithms that have been researched in recent years, the individual pitch control has demonstrated its effectiveness in wind turbine load reduction. Since the individual pitch control, like other load reduction algorithms, requires higher levels of actuator activity, one must take actuator constraints into account when designing the controller. This paper presents a method for the inclusion of such constraints into a predictive wind turbine controller. It is shown that the direct inclusion of constraints would result in a control problem that is nonconvex and difficult to solve. Therefore, a modification of the constraints is proposed that ensures the convexity of the control problem. Simulation results show that the developed predictive control algorithm achieves individual pitch control objectives while satisfying all imposed constraints.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The new grid regulations require that a grid-connected wind farm acts as a single controllable power producer. To meet this requirement a traditional wind farm control structure, which allowed ...individual wind turbines to internally define their power production, has to be modified. This paper investigates the opportunity for wind turbine load reduction that arises from dynamic power control of wind turbines. The wind farm controller design is proposed that utilizes coordinated power control of all wind turbines to achieve the wind farm regulation requirements and to minimize the wind turbine loads.
There are situations in which wind turbines must curtail their power, i.e. produce less power than is available from the wind. In such cases the wind turbine power can be increased or decreased if ...required. This gives an opportunity to strike a balance between varying power production and reducing wind turbine structural loading. To that end, a supervisory controller is designed that issues power references to the wind turbine and can be easily installed on already operational wind turbines. The wind turbine with a supervisory controller produces the required mean power, while reducing wind turbine loads by adding power variations. The extensive, realistic simulations are done to evaluate the influence of the proposed controller on the fatigue loads, extreme loads and the overall wind turbine operation. The results indicate that a significant reduction of fatigue loads can be achieved, which can increase the operating life of the structure. Furthermore, the proposed supervisory controller can be utilized as the main building block of a wind farm controller, which meets the grid code requirements and can be easily installed on very large wind farms due to minimal requirements on the farm-wide communication.
•The supervisory controller perturbates the wind turbine power references.•The reduction of structural fatigue loads is obtained.•Overall improvement in wind turbine operation is gained.•The supervisory controller can be used as a building block of a wind farm controller.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The use of wind power for generating electricity has experienced an uninterrupted and accelerating growth over last few decades and this growth is likely to continue. In order to enable even greater ...role of wind energy in power production it is necessary to increase the size and unit power of wind turbines. As wind turbines grow in size they are subjected to extreme loads and fatigue caused by nonuniform turbulent winds. Therefore, control algorithms that can assure load and fatigue reduction become a necessity. In this paper the individual pitch control for reduction of the periodic blade and hub loading is explored. To avoid problems related to the required blade loads measurements a method for their estimation based on other process variables is proposed. The performance of the individual pitch controller that uses such load estimations instead of measurements is tested and compared to the collective pitch control and the individual pitch control based on measured loads.
Linear parameter varying approach to wind turbine control Bobanac, Vedran; Jelavić, Mate; Perić, Nedjeljko
Proceedings of 14th International Power Electronics and Motion Control Conference EPE-PEMC 2010,
2010-Sept.
Conference Proceeding
Design of linear parameter varying control (LPV) for wind turbines is considered in this paper. Multivariable, robust control law, which can guarantee stability and desired performance in the whole ...operating region of the wind turbine, is obtained LPV controller is compared with a classical controller.
To enable further growth of wind turbine dimensions and rated power, it is essential to decrease structural loads that wind turbines experience. Therefore a great portion of research is focused on ...control algorithms for reduction of structural loads, but typically wind turbine rotor is considered to be perfectly symmetrical, and therefore such control algorithms cannot reduce structural loads caused by rotor asymmetries. In this paper, the reduction of wind turbine structural loads caused by rotor asymmetries is discussed. To this aim, suitable transformation of structural loads and control algorithm based on such transformation are proposed. Simulation results show that proposed control algorithm is capable of reducing structural loads caused by rotor asymmetries.
The use of wind energy for generating electricity has been constantly and rapidly increasing over last few decades and this growth is expected to continue. In order to enable even greater role of ...wind energy in power production wind turbinespsila sizes and rated powers must increase. As wind turbines grow in size they are subjected to extreme loads and fatigue caused by uniform turbulent winds. This prevents further growth of wind turbines. Therefore control methods that assure loads reduction become a necessity. In this paper methods for wind turbine loads reduction based on individual pitch control are explored. To overcome problems related to needed measurements of blade loads a method for their estimation based on loads measured on the fixed parts of the structure is proposed.
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