Coordinated pitch & torque control of large-scale wind turbine based on Pareto efficiency analysis

Abstract

For the existing pitch and torque control of the wind turbine generator system (WTGS), further development on coordinated control is necessary to improve effectiveness for practical applications. In this paper, the WTGS is modeled as a coupling combination of two subsystems: the generator torque control subsystem and blade pitch control subsystem. Then, the pole positions in each control subsystem are adjusted coordinately to evaluate the controller participation and used as the objective of optimization. A two-level parameters-controllers coordinated optimization scheme is proposed and applied to optimize the controller coordination based on the Pareto optimization theory. Three solutions are obtained through optimization, which includes the optimal torque solution, optimal power solution, and satisfactory solution. Detailed comparisons evaluate the performance of the three selected solutions and provide the optimized controller coordination suggestions according to different requirements.

Coordinated mechanical loads and power optimization of wind energy conversion systems with variable-weight model predictive control strategy

“…Firstly, the nonlinear wind turbine with the flexible drive-shaft is linearized into a three-order linear state-space model, where two control inputs (the references of generator torque and blade pitch angle) are considered in the same framework. The detailed linearization process and the wind turbine state-space model can be referred to [9]. Due to the strong effectiveness of MPC for industrial application, it is natural to discuss the MPC method for WECSs [7,25,26].…”

“…Once an appropriate parameter in the wind turbine model can be defined to characterize the blade loads, the related parameter can be optimized with the weight matrix in the model predictive controller. Motivated by this concept, several parameters within the wind turbine state-space model (the model can be referred to [9]) are calculated and compared with the blade bending moment parameters, which aims to find the correlation that the blade loads can be easily considered into the controller design and optimization. The analyzed parameters are normalized by the corresponding parameters obtained from an industrial baseline controller for the specific 5-MW wind turbine as in [29].…”

“…The tip speed ratio λ is defined as in (2). Detailed WECS models can be found in [2,8,9]. The wind power coefficient C p reflects the wind energy capture capability of the wind turbine, which is a nonlinear function of the blade pitch angle and tip speed ratio.…”

“…[27] has analyzed the effect of fixed pitch angle on the loads and moments as well as the aerodynamics of wind turbines. A coordination strategy was proposed in [9] through the Pareto optimization theory, while the controller participation is adjusted by the pole placement technique. Due to the actuator limiters or steady state errors, it is still difficult to implement the proposed state-feedback control for the industrial wind turbine.…”

Receding Horizon Optimization of Wind Farm Active Power Distribution with Power Tracking Error and Transmission Loss

“…From an energy conversion perspective, the wind turbine generator system (WTGS) is the device that converts wind energy into electrical energy, which takes the active power set-point as input and outputs the electric power to the grid. Controllers within the WTGS are working in coordination to guarantee the WTGS power output tracks the power demand [1]. Over the past few years, many achievements have been introduced in wind turbine control to improve the wind turbine load conditions and stabilize the power output.…”