LQ Optimal Control for Power Tracking Operation of Wind Turbines

TL;DR

This paper introduces an LQ optimal control method for wind turbine power tracking that improves reference tracking and reduces mechanical wear compared to traditional controllers, using a multivariable control approach in simulation.

Contribution

It presents a novel LQ optimal control strategy for wind turbines that integrates reference trajectory generation with multivariable control for improved power tracking.

Findings

Similar power tracking performance to state-of-the-art methods

Lower mechanical wear with the LQ controller

Good reference tracking demonstrated in simulations

Abstract

In this paper, an approach for active power control of individual wind turbines is presented. State-of-the-art controllers typically employ separate control loops for torque and pitch control. In contrast, we use a multivariable control approach. In detail, active power control is achieved by using reference trajectories for generator speed, generator torque, and pitch angle such that a desired power demand is met if weather conditions allow. Then, a linear quadratic (LQ) optimal controller is used for reference tracking. In an OpenFAST simulation environment, the controller is compared to a state-of-the-art approach. The simulations show a similar active power tracking performance, while the LQ optimal controller results in lower mechanical wear. Moreover, the presented approach exhibits good reference tracking and by improving the reference trajectory generation further performance increases can be expected.