Transient stability enhancement of a gridconnected wind farm using an adaptive neurofuzzy controlled-flywheel energy storage system

With the rapid growth of the wind energy systems in the past years and their interconnection with the existing power system networks, it has become very significant to analyse and enhance the transient stability of the wind energy conversion systems connected to the grid. This study investigates the transient stability enhancement of a grid-connected wind farm using doubly-fed induction machine-based flywheel energy storage system. A cascaded adaptive neuro-fuzzy controller (ANFC) is introduced to control the insulated gate bipolar transistor switches-based frequency converter to enhance the transient stability of the grid-connected wind farm. The performance of the proposed control strategy is analysed under a severe symmetrical fault condition on both a single-machine infinite bus model and the IEEE-39 bus New England test system. The transient performance of the system is investigated by comparing the results of the system using the proposed ANFCs with that of the black-box optimisation technique-based proportional-integral controllers. The validity of the system is verified by the simulation results which are carried out using PSCAD/EMTDC environment

ANT-colony optimization-direct torque control for a doubly fed induction motor: An experimental validation

Direct Torque Control (DTC) presents an optimal solution to control the behaviors of the alternative motors, compared to other controls, because of several advantages offered by this technique, the speed overshoots, fluxes, and torque ripples remain the major factors which minimize the DTC robustness. The regulation speed in DTC is carried out by the classic Proportional Integrator Derivative (PID), which is known for its higher robustness in linear systems, except that in the case of non-linear systems, the PID controller gives poor reactions to variations in the system's parameters. The best solutions adopted in this situation are often based on optimization algorithms that generate the controller's gains in each period where there is an internal or external perturbation, adapting the behaviors of the PID against the system's nonlinearity. For that reason, this work is focused on the theoretical studies and experimental validation on dSPACE Board DS1104 of the new proposed approach based on PID speed regulation, optimized by the Ant Colony Optimization algorithm (ACO) for DTC, applied to both sides of the Doubly Fed Induction Motor (DFIM), to overcome the previous drawbacks cited at the beginning. The new combined ACO-DTC strategy has been studied for optimizing the gains of the PID controller by using a cost function such as Integral Square Error (ISE). The proposed approach is implemented on Matlab/Simulink to validate the objectives adopted by this strategy. The simulation and experimental results extracted from Matlab and ControlDesk have proved the efficiency of the proposed ACO-DTC with the system's nonlinearity, which attribute different enhancements in the global system performance.This publication was made possible by Qatar University Collaborative Research grant # [ QUCG-CENG-21/22-1 ] from the Qatar University. The statements made herein are solely the responsibility of the authors. The APC is funded by the Qatar NAtional Library, QatarScopu

Modelling and simulation of a grid connected doubly fed induction generator for wind energy conversion system

The Doubly Fed Induction Generator (DFIG) based wind turbine with variable speed variable-pitch control scheme is the most popular wind power generator in the wind power industry. This machine can be operated either in grid connected or standalone mode. A thorough understanding of the modelling, control, and dynamic as well as the steady state analysis of this machine in both operation modes is necessary to optimally extract the power from the wind and accurately predict its performance. In this thesis, first a three phase PWM voltage source converter models expressed in the ABC and the DQO synchronous reference frame with its control schemes are developed and analysed. Then a DFIG-based wind turbine model connected to a constant voltage and frequency grid is developed in the Matlab/Simulink software in detail and its corresponding generator and turbine control structure is implemented. A thorough explanation of this control structure as well as the steady state behaviour of the overall wind energy conversion system which includes the aerodynamic models of the wind turbine, the DFIG models and the three-phase two-level PWM voltage source converter models are presented. A developed control schemes are also necessary to achieve useful output power from the WECS. These control schemes include the generator-side converter control, the grid-side converter control, the pitch angle control and the maximum power point tracking control. The grid-side converter controller is used to maintain the constant voltage across the capacitor and produce a unity power factor operation of the grid. The generator-side converter controller is used to regulating the torque, active power and reactive power

Contribution to the Control of Doubly Fed Induction Machine DFIM

-IIAbstract Currently, doubly fed induction generators (DFIGs) are widely used for wind turbines. Compared to other variable-speed generators; the main advantage of the DFIG is that the power electronic devices must deal with only about a third of the generator power, compared to full power converters used in synchronous generators . This difference reduces the costs and losses in the power electronic components, rather than other solutions, such as fully converting systems; finally, the overall efficiency is improved. Furthermore, among all the induction generator configurations for generation systems the use of (DFIG) configuration with back to back pulse width modulated voltage source converters (VSC) is one of the best topologies available and it is suitable for both grid connected systems as well as standalone systems. Here only stand-alone application of DFIG is considered. In this thesis, mathematical modelling of doubly fed induction machine is presented. Two control approaches are proposed to improve the control of the rotor side converter which give the best solution to overcome the drawbacks of the recent control methods and provide a high performance stator- voltage magnitude and frequency regulation for all possible operation scenarios (voltage magnitude, load, and rotor speed variations). Various aspects of standalone DFIG generation system such as stator-voltage magnitude and frequency regulation, computational requirement minimization, sensors number reduction, from rotor side converter control is carried out. All proposed control methods have been verified in both simulation and 3 kW DFIG laboratory experimental bench

SISTEM KENDALI ADAPTIF NEURO-FUZZY PID PADA KAPAL KATAMARAN TANPA AWAK

Kendali otomatis dibutuhkan oleh kapal katamaran tanpa awak dalam menavigasi menuju arah tertentu dan dapat menangani gangguan serta perubahan kondisi dengan efektif dan optimal. Kendali PID cocok untuk pengendalian kapal, namun mempunyai kelemahan dalam pencarian gain PID optimal untuk setiap kondisi. Fuzzy mampu menangani penjadawalan gain PID untuk setiap kondisi dan neural network mampu mengoptimasi desain fuzzy, sehinggadilakukan penggabungan menjadi kendali adaptif neuro fuzzy PID (N-F PID). N-F PID merupakan kendali PID dengan penjadawalan gain PID (Kp, Ki dan Kd) yang dinamis berdasarkan besarnya nilai error dan delta error oleh neuro fuzzy. Neuro fuzzy yang digunakan adalah adaptif neuro fuzzy inference system (ANFIS). ANFIS mampu melakukan pembelajaran dengan training data baru untuk memperbaiki performa. Training data baru didapatkan dari proses tuning dengan mengalikan output masing-masing fuzzy yang belum terlatih dengan konstanta tertentu hingga didapatkan settling time cepat dan persentase overshoot maksimum kecil.Simulasi N-F PID dengan Matlab dan ekperimen kapal katamaran menunjukkan N-F PID mempunyai performa yang lebih baik dari pada kendali fuzzy PID dan kendali PID, dilihat dari settling time dan persentase overshoot maksimum. N-F PID mempunyai tingkat presisi pengendalian yang lebih rendah daripada kendali fuzzy PID dan PID berdasarkan data eksperimen

Torque Control

This book is the result of inspirations and contributions from many researchers, a collection of 9 works, which are, in majority, focalised around the Direct Torque Control and may be comprised of three sections: different techniques for the control of asynchronous motors and double feed or double star induction machines, oriented approach of recent developments relating to the control of the Permanent Magnet Synchronous Motors, and special controller design and torque control of switched reluctance machine

Low-head pumped hydro storage: A review of applicable technologies for design, grid integration, control and modelling

To counteract a potential reduction in grid stability caused by a rapidly growing share of intermittent renewable energy sources within our electrical grids, large scale deployment of energy storage will become indispensable. Pumped hydro storage is widely regarded as the most cost-effective option for this. However, its application is traditionally limited to certain topographic features. Expanding its operating range to lowhead scenarios could unlock the potential of widespread deployment in regions where so far it has not yet been feasible. This review aims at giving a multi-disciplinary insight on technologies that are applicable for low-head (2-30 m) pumped hydro storage, in terms of design, grid integration, control, and modelling. A general overview and the historical development of pumped hydro storage are presented and trends for further innovation and a shift towards application in low-head scenarios are identified. Key drivers for future deployment and the technological and economic challenges to do so are discussed. Based on these challenges, technologies in the field of pumped hydro storage are reviewed and specifically analysed regarding their fitness for low-head application. This is done for pump and turbine design and configuration, electric machines and control, as well as modelling. Further aspects regarding grid integration are discussed. Among conventional machines, it is found that, for high-flow low-head application, axial flow pump-turbines with variable speed drives are the most suitable. Machines such as Archimedes screws, counter-rotating and rotary positive displacement reversible pump-turbines have potential to emerge as innovative solutions. Coupled axial flux permanent magnet synchronous motor-generators are the most promising electric machines. To ensure grid stability, grid-forming control alongside bulk energy storage with capabilities of providing synthetic inertia next to other ancillary services are required

Design of robust MPPT controller for grid-connected PMSG-Based wind turbine via perturbation observation based nonlinear adaptive control

This paper presents a robust maximum power point tracking (MPPT) control scheme for a grid-connected permanent magnet synchronous generator based wind turbine (PMSG-WT) using perturbation observation based nonlinear adaptive control. In the proposed control scheme, system nonlinearities, parameter uncertainties, and external disturbances of the PMSG-WT are represented as a lumped perturbation term, which is estimated by a high-gain perturbation observer. The estimate of the lumped perturbation is employed to compensate the actual perturbation and further achieve adaptive feedback linearizing control of the original nonlinear system, without requiring the detailed system model and full state measurements. The effectiveness of the proposed control scheme is verified through both simulation studies and experimental tests. The results show that, compared with the conventional vector controller and the standard feedback linearizing controller, the proposed control strategy provides higher power conversion efficiency and has better dynamic performances and robustness against parameter uncertainties and external disturbances