Christian Tutivén

Hardware in the Loop Wind Turbine Simulator for Control System Testing

This chapter illustrates how to set up an inexpensive but effective Hardware-in-the-Loop (HIL) platform for the test of wind turbine (WT) controllers. The dynamics of the WT are simulated on the open-source National Renewable Energy Laboratory WT simulator called FAST (Fatigue, Aerodynamics, Structures, and Turbulence), which emulates all required input signals of the controller and reacts to the controller commands (almost) like an onshore real turbine of 5 MW. The dynamic torque control system runs on an open hardware Arduino microcontroller board, which is connected to the virtual WT via USB. In particular, the power generation control in the full load region for variable-speed variable-pitch wind turbines is considered through torque and pitch control. The HIL proposed platform is used to characterize the behavior of the WT in normal operation as well as in fault operation. In particular, a stuck/unstuck fault is modeled and the behavior of a proposed chattering torque controller is analyzed in comparison to a baseline torque controller.

Passive fault tolerant control strategy in controlled wind turbines

In wind turbines (WTs), some faults can induce saturation of the control signal, and these saturation nonlinearities might lead to instability. Therefore, a robust system against saturation can better deal with faults. In this work, an avoid saturation strategy is proposed for the torque control of WTs. The key idea is that the reference power and generator speed set-points are hysterically manipulated. Simulation results from a 5MW benchmark model show that the proposed strategy has a clear added value with respect to the baseline controller not only in healthy condition but also in presence of a realistic fault.

Variable structure strategy to avoid torque control saturation of a wind turbine in the presence of faults

Every physical actuator is subject to saturation. It has been well recognized that, when the actuator saturates, the performance of the closed-loop system (designed without considering actuator saturation) may seriously deteriorate. In extreme cases, the system stability may even be lost. This paper proposes an avoid saturation strategy for the torque controller of a wind turbine benchmark model. The simulation results show that the proposed strategy has a clear added value with respect to the baseline controller (well- accepted industrial controller) in the presence of faults. Another advantage of the contributed method is that conservative bounds for the actuator torque can be fixed in order to extend the service life of the wind turbine.

Active fault tolerant control for pitch actuators failures tested in a hardware-in-the-loop simulation for wind turbine controllers

The number and complexity of control systems in wind turbines (WT) is expanding rapidly, and their design can be the difference between an immensely profitable system or a damaged system. Designing a robust control system requires to test the control algorithms in the actual controller hardware. However, WT are large and expensive, thus we would like to perform this test virtually, without using prototypes of the WT.