Jose Carlos Teles Campos

Robustness and Performance Analysis for the Linear Quadratic Gaussian/Loop Transfer Recovery with Integral Action Controller Applied to Doubly Fed Induction Generators in Wind Energy Conversion Systems

Abstract This article presents a novel application of the multivariable robust controller linear quadratic Gaussian/loop transfer recovery with integral action to a doubly fed induction generator. Furthermore, this study investigates robustness and performance in the face of variations of internal parameters of the machine and speed. Experimental results obtained from a laboratory prototype that uses a 2-kW machine are presented to validate and demonstrate the robustness and performance of the proposed controller through the comparison with the proportional and integral controller employed in a wind energy conversion system with doubly fed induction generator machines.

Identification and adaptive speed control for switched reluctance motor using DSP

In this paper, a simple adaptive speed control for switched reluctance motor (SRM) is described and implemented using Digital Signal Processor (DSP). The controller structure design is based on PWM control scheme that have been used for the SRM current controller. To realize the speed control, the speed reference is calculated as function of current machine. From experimental results it is shown that the overall switched reluctance motor speed control gives good transient and steady state responses.

Modeling and controller performance assessment for a switched reluctance motor drive based on setpoint relay.

This paper considers the implementation of a current control method for switched reluctance motors (SRMs) and presents a novel approach to the accurate on-line modeling of an SRM drive. A simple autotuning technique for the SRM drives using a PWM controller is considered. Furthermore, conventional PI control and Internal Model Control (IMC) are considered to validate this method and present corresponding robust control analysis for the process. The control structures are comparatively analyzed using standard robustness measures for stability and performance. The proposed PWM controller is simulated and a hardware prototype is then implemented using digital signal processor control to evaluate the method using a 12/8, three-phase SRM. The experimental results of the SRM drive model validates the performance of the current loop.

Anti-windup predictive current controller applied to a DFIG-based wind turbine under low DC-link voltage

During unsymmetrical/symmetrical voltage sags, there is a drop in the DC-link voltage, thus it can lead to serious impacts, i.e. current and power oscillations, to a double fed induction generator (DFIG) with a simplified power converter (rotor side converter with three-phase passive diode rectifiers). Therefore, this paper deals with an anti-windup predictive current controller applied to a DFIG-based wind turbine under low DC-link voltage condition. In order to investigate the transient overshoots and ripples that appear in the rotors current and DC-link voltage, several experimental tests are carried out. The test results shows the effectiveness of the proposed anti-windup predictive controller when it is compared to the PI controller.

Robust analysis of a predictive controller of DFIG wind energy systems

This paper deals with the robustness analysis of an anti-windup predictive current controller applied to a DFIG-based wind turbine in the presence of parameter variation. Experimental results were carried out, under the changing of the rotor speed, power and voltage sags, for a 3.7kW DFIG to verify the robustness of the designed controller.

Robust Generalized Predictive Control applied to the mitigation of electromagnetic torque oscillations in a wind energy conversion system based on DFIG

In order to make wind power generation truly cost-effective and reliable, an advanced control technique must be used. This paper presents the development of a control strategy based on the rotor current loop using the Generalized Predictive Control (GPC) approach applied to a Doubly-Fed Induction Generator (DFIG)-based wind turbine. The controller is designed to minimize oscillations in the generator electromagnetic torque by filtering the control signal. Besides, a new methodology for tuning the controller is proposed based on a single parameter that allows good tradeoffs among noise attenuation of the control signal, disturbance rejection, and system robustness during operation. Simulation results are shown and discussed to demonstrate the merit of the proposal, as the performance and robustness of the algorithm are evaluated when applied to a DFIG-based wind energy conversion system (WECS).

Robust generalized predictive control applied to the rotor side converter of a wind power generator system based on DFIG

This paper presents the model and the control of the rotor current loop a double-fed induction generator based on a robust generalized predictive controller. The controller is designed to minimize the control signal and ensure the reference tracking quickly and with a minimum of overshoot. Furthermore, it is proposed a new methodology for controller tuning based on a single parameter that allows a balance between noise attenuation of the control signal, disturbance rejection and robustness of the system during operation. Through computer simulation, the relationship between the tuning parameter and the system dynamics is analyzed. The simulations results validate the performance of the proposed controller when applied to a DFIG-based wind generation system.

Simulation of converters using Scilab/Scicoslab

This paper demonstrates the potential application of free software Scilab/ScicosLab in the study of a DC-DC Cúk converter, while the advantages of such practice are clearly identified in this particular application. Scilab/ScicosLab is a free and open-source software (FOSS), developed for scientific and industrial use. Mathematical equations and the algorithm for solving them are developed and the results show that Scilab/ScicosLab can be used to analyze not only the chosen converter, but other topologies as well. The software is adequate for teaching laboratory power electronic experiments regarding both mathematical and physical analysis. Besides this software can be used in both Windows and Linux platforms.