Performance comparison of control schemes for variable-speed wind turbines

Abstract

We analyze the performance of different control schemes when applied to the regulation problem of a variable-speed representative wind turbine. In particular, we formulate and compare a wind-scheduled PID, a LQR controller and a novel adaptive non-linear model predictive controller, equipped with observers of the tower states and wind. The simulations include gusts and turbulent winds of varying intensity in nominal as well as off-design operating conditions. The experiments highlight the possible advantages of model-based non-linear control strategies.

A review on applications of model predictive control to wind turbines

“…In the past, the wind turbine control objectives in the industry focus on rotor speed regulation with a PI design. Many papers suggest that MIMO control and advanced control strategies can improve the wind turbine speed regulation performance and load mitigation [3], [4], [5].…”

“…Some publications [15] suggest that MPC controllers, due to their effective use of information about system constraints and predicted behaviour, can avoid unnecessary shutdowns due to overspeed limits. Other publications [4] and [16] suggest that MPC controllers improve upon the performance of alternative advanced control techniques such LQR and LQG; again this will be largely due to the effective handling of constraint information.…”

“…In the literature there are different methods used in estimating the wind information. Typically, inversion of static aerodynamic model [12], [21] and random walk model [4] are common choices for wind estimation. Recently, with the increased maturity of the LIDAR technology, some papers obtain the estimated future wind information via LIDAR [7], [15].…”

“…al. [4] design a NMPC controller with collective blade pitch and generator torque as control inputs and they compared the NMPC controller with scheduled LQR and wind-scheduled PID controllers. The hub wind speed model is built based on random walk model.…”

Control Design Methodologies for Vibration Mitigation on Wind Turbine Systems

“…A brief description of the theory behind the DAC will be given shortly, while an implementation and testing of DAC for the WT system will be done in Section 4. In addition to the above mentioned control schemes are methods as Model Predictive Control (MPC) (Henriksen, 2007) (Bottasso et al, 2007) for more on this).…”