Showing papers by "Ron J. Patton published in 2018"
TL;DR: In this article, a fault-tolerant control (FTC) scheme was proposed for wind turbine pitch actuator faults to recover the nominal pitch dynamics, which is based on estimation of pitch system states and fault indicator function using an adaptive step-by-step sliding mode observer.
120 citations
TL;DR: The FE/FTC decoupling and the perturbation compensation (in the control) together contribute to a new integrated FTC strategy with more design freedom, less complexity and higher robustness.
52 citations
TL;DR: In this paper, a 1/50 scale cylindrical heaving point absorber (PA) is used to model nonlinear fluid viscous and mechanical friction dynamics for wave energy conversion.
Abstract: Although the heaving point absorber (PA) concept is well known in wave energy conversion research, few studies focus on appropriate modeling of nonlinear fluid viscous and mechanical friction dynamics. Even though these concepts are known to have nonlinear effects on the hydrodynamic system, most research studies consider linearity as a starting point and in doing so have a weak approach toward modeling the true dynamic behavior, particularly close to resonance. The sole use of linear modeling leads to limited ability to develop control strategies capable of true power capture optimization and suitable device operation. Based on a 1/50 scale cylindrical heaving PA, this research focuses on a strategy for hydrodynamic model development and experimental verification. In this study, nonlinear dynamics are considered, including the lumped effect of the fluid viscous and mechanical friction forces. The excellent correspondence between the derived nonlinear model and wave tank tested PA behaviors provides a strong background for wave energy tuning and control system design.
49 citations
TL;DR: In this paper, three approaches are proposed to estimate the excitation force from wave elevation, measurement of pressure, acceleration, and displacement, and observing the force via an unknown input observer.
40 citations
TL;DR: In this paper, a non-linear state-space model (NSSM) considering a quadratic viscous term is used to simulate PAWEC hydrodynamics.
38 citations
TL;DR: Results indicate the feasibility of using the GP approach in a real application from the viewpoints of high forecasting accuracy and acceptable computational complexity and the overall outcome is that the GP outperforms its counterparts.
15 citations
TL;DR: A fault-tolerant control (FTC) strategy using adaptive sliding mode estimation is combined with a traditional IPC system based on two different control methods (Proportional-Integral and H∞ loop-shaping) that maintains the nominal pitch performance and removes the negative effects of pitch actuator faults on generator power and unbalanced blade loads perfectly.
12 citations
01 Sep 2018
TL;DR: This paper shows how accurate short-time wind speed data can be predicted from past measurements using a Gaussian Process (GP) model based on Matern class kernel and detailed simulations are carried out using the FAST NREL 5MW wind turbine model.
Abstract: An important control challenge for large wind turbines is to maximize the power capture whilst at the same time mitigating against potential fatigue damage. It is now quite well understood that this challenge may be beyond the capability of classical controllers, even when individual pitch actuation is considered. Recent research shows that preview controllers requiring future wind speed knowledge will offer an enhanced combination of good load mitigation and power capture performance. In this context, some preview control schemes use future wind speed prediction data generated by Light Detection and Ranging (LiDAR) systems. However, LiDAR devices tend to be expensive and may not always be available for individual wind turbines. This paper shows how accurate short-time wind speed data can be predicted from past measurements using a Gaussian Process (GP) model based on Matern class kernel. The short-time wind speed prediction is combined with model predictive control (MPC) and detailed simulations are carried out using the FAST NREL 5MW wind turbine model.
6 citations