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The main objective of presented article is here to focus how efficiently minimise the deviations in frequency and area control error caused by load fluctuations and uncertainties in load under the deregulated power system. This wo...
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The main objective of presented article is here to focus how efficiently minimise the deviations in frequency and area control error caused by load fluctuations and uncertainties in load under the deregulated power system. This work is carried out to eliminate the frequency errors by using fractional order proportional integral (FOPI) controller under deregulated environment by considering the effect of one possible bilateral contract scenario. Because of system nonlinearities, uncertainties and continuously fluctuant load demand the design of these controllers is quite complicated in deregulated environment. The proposed work is to enhance the system parameters like transmitted line power, frequency deviation error, and area control error (ACE) using fractional order PI controller for hydro-thermal system and thermal-thermal system under deregulated environment. The results have been analysed with classical integer order PI controller and FOPI controller. It is observed that the efficacy of the results is satisfied and improved when compared with previous work.
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A simple method is proposed to design parallel cascade controllers for open loop unstable processes. A proportional (P)controller is considered for the secondary loop and a proportional integral (PI) controller is considered for t...
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A simple method is proposed to design parallel cascade controllers for open loop unstable processes. A proportional (P)controller is considered for the secondary loop and a proportional integral (PI) controller is considered for the primary loop (P/PI control configuration). Coefficients of the corresponding powers of s (Laplace variable), in the numerator is matched with the coefficients of the corresponding powers of s in the denominator of a closed loop transfer function for a servo problem. Three simulation case studies are considered in this paper. The first case involves a stable secondary loop process and an unstable primary process, the second case involves both unstable primary and secondary processes and the third one, a simulation application to a nonlinear bioreactor model equations. For comparison purposes, P/PI controller design is also carried out by improved simultaneous relay autotuning method, synthesis method and minimizing ISE criterion method. It is found that the proposed method gives a better performance. Robust stability analysis using the complimentary sensitivity function is carried out The present method is found to be more robust (C) 2016 Published by Elsevier Ltd. on behalf of ISA.
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Direct torque control (DTC) is the simplest method meant for torque control of a three-phase induction motor. The present study emphasizes speed control by using an external speed loop with DTC controller. The variable torque comm...
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Direct torque control (DTC) is the simplest method meant for torque control of a three-phase induction motor. The present study emphasizes speed control by using an external speed loop with DTC controller. The variable torque command is generated from the speed loop using a conventional PI controller which has been implemented in experimental work to validate the simulation results. A fuzzy rule-based speed controller has been developed in this study for comparison purpose. The speed response is faster using conventional PI controller, but fuzzy controller minimizes the ripple content in torque. The design of the speed controller has been made economical by using low-cost discrete electronic hardware components.
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Switched Reluctance Motor (SRM) suffers from current ripples and speed oscillations due to variations in loading conditions. Most of researches focus on enhancing the performance of SRM through speed and current controllers. This ...
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Switched Reluctance Motor (SRM) suffers from current ripples and speed oscillations due to variations in loading conditions. Most of researches focus on enhancing the performance of SRM through speed and current controllers. This paper proposes two relatively new strategies to enhance the performance of the SRM. First one is optimizing the gain of classical proportional integral (PI) controller using sine-cosine optimization (SCO). The other strategy is to use adaptive PI controller. The proposed techniques are evaluated under several loading conditions with the proposed strategies applied in the current control system. The results deduced the superiority of adaptive controller under all loading conditions presented.
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Direct current servo motors (DCSMs) are frequently used in the areas of industry which require different operating conditions. Traditional PI controllers with constant coefficients are not sufficient for the speed and torque contr...
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Direct current servo motors (DCSMs) are frequently used in the areas of industry which require different operating conditions. Traditional PI controllers with constant coefficients are not sufficient for the speed and torque control of these motors, because of that their dynamic characteristics change in different operating conditions. The speed and load changes cause positive and negative overshoots and oscillations. In this study, in order to overcome these problems, the speed and torque controls of DCSM were implemented by using the cascade fuzzy PI controller, where the torque control was carried out by the current control. For this aim, a cascade fuzzy PI controller was designed for controlling the speed and the current of DCSM. Here, the fuzzy logic controllers in cascade fuzzy PI controllers adjusted the proportional and integral coefficients according to the speed and the change of speed, and the current and the change of current. The experimental results showed that the performance of cascade fuzzy PI controller was better than that of traditional PI controller for different operating speed and load conditions.
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This paper presents the design, stability analysis and experimental validation of a computationally non-intensive, model-free, intelligent proportional-integral (iPI) controller for flexible joint manipulators. In order to show th...
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This paper presents the design, stability analysis and experimental validation of a computationally non-intensive, model-free, intelligent proportional-integral (iPI) controller for flexible joint manipulators. In order to show the performance of the iPI controller, it is compared with classical proportional-integral and proportional-integral-derivative controllers. Based on this comparison, the iPI-controlled system achieved a better than 60% tracking accuracy for both kane trajectory and sine input tracking. The iPI controller also significantly reduced transient swings in the flexible joint of the manipulator, when tracking a train of pulses. Moreover, the iPI controlled system successfully eliminated both disturbances and noise effects from the dynamics of the manipulator.
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This manuscript is part of a long-term research, aimed at establishing methodologically grounded relationships between model- and relay-based tuning of industrial regulators, and at consequently deriving synthesis procedures that ...
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This manuscript is part of a long-term research, aimed at establishing methodologically grounded relationships between model- and relay-based tuning of industrial regulators, and at consequently deriving synthesis procedures that couple the advantages of model-based tuning to the simplicity and clarity of relay-based identification. In this work, the addressed controller structure is the "PI+p", i.e., a PI augmented with an additional, stable pole. The advantages of using the combined model-relay-based approach on that structure are evidenced, by means of both simulation and experimental results.
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Direct-current (DC) microgrids have gained worldwide attention in recent decades due to their high system efficiency and simple control. In a self-sufficient energy system, voltage control is an important key to dealing with upcom...
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Direct-current (DC) microgrids have gained worldwide attention in recent decades due to their high system efficiency and simple control. In a self-sufficient energy system, voltage control is an important key to dealing with upcoming challenges of renewable energy integration into DC microgrids, and thus energy storage systems (ESSs) are often employed to suppress the power fluctuation and ensure the voltage stability. In this paper, the performances of three voltage control strategies for DC microgrids are compared, including the proportion integration (PI) control, the fuzzy PI control and particle swarm optimization (PSO) PI control. Particularly, two kinds of ESSs including battery and advanced adiabatic compressed air energy storage (AA-CAES) with different operational characteristics are installed in the microgrid, and their impacts on voltage control are investigated. The control performances are comprehensively compared under different control schemes, various scenarios of renewable energy fluctuations, participation in the control of the two ESSs or not, and different fault conditions. Additionally, the dynamic performances of the ESSs are exhibited. The results verify the validity of the control schemes and the feasibility of the configuration of the ESSs into the DC microgrid.
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A novel speed control design of 4WD electric vehicle (EV) to improve the comportment and stability under different road constraints condition is presented in this paper. The control circuit using intelligent adaptive fuzzy PI cont...
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A novel speed control design of 4WD electric vehicle (EV) to improve the comportment and stability under different road constraints condition is presented in this paper. The control circuit using intelligent adaptive fuzzy PI controller is proposed. Parameters which guide the functioning of PI controller are dynamically adjusted with the assistance of fuzzy control. The 4WD is powered by four motors of 15 kilowatts each one, delivering a 384 N.m total torque. Its high torque (338 N.m) is instantly available to ensure responsive acceleration performance in built-up areas. The electric drive canister of tow directing wheels and tow rear propulsion wheels equipped with tow induction motors thanks to their light weight simplicity and their height performance. Acceleration and steering are ensure by electronic differential, the latter control separately deriving wheels to turn at any curve. Electric vehicle are submitted different constraint of road using direct torque control. Electric vehicle are simulated in Matlab Simulink. The simulation results have proved that the intelligent fuzzy PI control method decreases the transient oscillations and assure efficiency comportment in all topologies road constraints, straight, curved road, descent.
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The article addresses the problem of developing low-cost controllers used in tracking control for mobile robots. A simplified dynamic model that can well characterize the wheeled mobile robots with two degrees of freedom is first ...
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The article addresses the problem of developing low-cost controllers used in tracking control for mobile robots. A simplified dynamic model that can well characterize the wheeled mobile robots with two degrees of freedom is first proposed. The control system-structure involved contains two control loops for controlling the forward velocity and the angle between the heading direction and the x-axis. The reference trajectory of the robot is obtained by employing the artificial potential field method used in obstacle avoidance, accompanied by some simple computations in terms of the tracking errors for the x- and y-axes and of the maximum accepted values for these errors. In addition, the authors present development methodologies for three types of tracking controllers: the PI controllers, a version of PI-fuzzy controllers, and a version of sliding mode-PI controllers, based on the Extended Symmetrical Optimum method applied to the basic linear' PI controllers and by adding nonlinear features of fuzzy- or sliding mode-type for obtaining control system performance enhancement. Simulation results are provided to validate the proposed dynamic model and navigation controllers.
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