Carla Solange Pires Correia Viveiros

Application of a discrete adaptive LQG and fuzzy control design to a wind turbine benchmark model

This paper deals with a wind turbine control simulation supported by the use of computational tools appropriate to simulate complex systems. High performance and reliability are required for wind turbines to be competitive within the energy market. A key challenge for control systems is the wind power which is an uncontrolled input and also acts as a disturbance. A discrete adaptive LQG (linear quadratic) as well as a fuzzy PI control design of publicly available wind turbine benchmark models are proposed and simulation results by Matlab/Simulink are shown in order to prove the effectiveness of the design.

Fuzzy, integer and fractional-order control: Application on a wind turbine benchmark model

This paper presents a comparison between proportional integral control approaches for variable speed wind turbines. Integer and fractional-order controllers are designed using linearized wind turbine model whilst fuzzy controller also takes into account system nonlinearities. These controllers operate in the full load region and the main objective is to extract maximum power from the wind turbine while ensuring the performance and reliability required to be integrated into an electric grid. The main contribution focuses on the use of fractional-order proportional integral (FOPI) controller which benefits from the introduction of one more tuning parameter, the integral fractional-order, taking advantage over integer order proportional integral (PI) controller. A comparison between proposed control approaches for the variable speed wind turbines is presented using a wind turbine benchmark model in the Matlab/Simulink environment. Results show that FOPI has improved system performance when compared with classical PI and fuzzy PI controller outperforms the integer and fractional-order control due to its capability to deal with system nonlinearities and uncertainties.

Control and Supervision of Wind Energy Conversion Systems

This paper is about a PhD thesis and includes the study and analysis of the performance of an onshore wind energy conversion system. First, mathematical models of a variable speed wind turbine with pitch control are studied, followed by the study of different controller types such as integer-order controllers, fractional-order controllers, fuzzy logic controllers, adaptive controllers and predictive controllers and the study of a supervisor based on finite state machines is also studied. The controllers are included in the lower level of a hierarchical structure composed by two levels whose objective is to control the electric output power around the rated power. The supervisor included at the higher level is based on finite state machines whose objective is to analyze the operational states according to the wind speed. The studied mathematical models are integrated into computer simulations for the wind energy conversion system and the obtained numerical results allow for the performance assessment of the system connected to the electric grid. The wind energy conversion system is composed by a variable speed wind turbine, a mechanical transmission system described by a two mass drive train, a gearbox, a doubly fed induction generator rotor and by a two level converter.

On Wind Turbine Model Predictive Pitch Control: An Event-Based Simulation Approach

This paper is about a hierarchical structure with an event-based supervisor in a higher level and a model predictive control (MPC) in a lower level applied to a wind turbine. The event-based supervisor analyzes the operation conditions to determine the state of the wind turbine. The objectives and constraints of the model predictive controller can also be adjusted by this supervisory controller. This hierarchical structure is able to ensure the performance and reliability required for a wind turbine to be integrated into an electric grid. Comparisons between model predictive pitch control and a default proportional integral pitch controller applied to a wind turbine benchmark are given and simulation results by Matlab/Simulink are shown in order to prove the effectiveness of the proposed approach.

Fractional order control on a wind turbine benchmark

This paper is about a hierarchical structure with an event-based supervisor in a higher level and a fractional-order proportional integral (FOPI) in a lower level applied to a wind turbine. The event-based supervisor analyzes the operation conditions to determine the state of the wind turbine. This controller operate in the full load region and the main objective is to capture maximum power generation while ensuring the performance and reliability required for a wind turbine to be integrated into an electric grid. The main contribution focus on the use of fractional-order proportional integral controller which benefits from the introduction of one more tuning parameter, the integral fractional-order, taking advantage over integer order proportional integral (PI) controller. Comparisons between fractional-order pitch control and a default proportional integral pitch controller applied to a wind turbine benchmark are given and simulation results by Matlab/Simulink are shown in order to prove the effectiveness of the proposed approach.

Wind energy conversion system under a supervisor deterministic finite state machine

This paper presents a simulation of an onshore energy conversion system connected to the electric grid and under a strategy of a supervisor control based on deterministic version of a finite state machine. The simulation is planned to address an analysis on performance due to the action of the supervisor. The supervisor is included at the higher level, having the objective of analyzing the operational states according to the wind speed. The energy conversion system is equipped with a doubly-fed induction generator and a variable speed variable pitch wind turbine. The analysis is carried by computer simulations and the obtained results allow assessment to the performance of the system. A comparison of the wind energy conversion system performance with or without the supervisor is carried out in order to access the influence of the strategy on the performance.

Wind energy conversion system control using distinct controllers for different operating regions

This paper presents a control strategy based on two distinct controllers for different operating regions applied to a wind turbine benchmark. In previous works, we proposed the control of a wind turbine using two distinct controllers for all operating regions. The contribution of this work focus on the use of two distinct controllers for two different operation regions, the fuzzy proportional integral controller in the partial load region, i.e., Region II, and the use of model predictive controller in the full load region, i.e., Region III. The distinct controllers applied on the different operation regions are compared to a standard controller and the simulation results show the efficacy of the proposed control approach.