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The main aim of this work was the maximization of the energy saving of balanced and unbalanced distribution power systems via system reconfiguration and the optimum capacitor’s bank choice, which were estimated by using a new algorithm: modified Tabu search and Harper sphere search (MTS-HSSA). The results demonstrated that the proposed method is appropriate for energy saving and improving performance compared with other methods reported in the literature for IEEE 33-bus adopted systems, including large scale systems such as IEEE 119 and the IEEE 123 unbalanced distribution system. Moreover, it can be used for unbalanced distribution systems distributed generators (DGs). The results demonstrated that the proposed method (the optimal choice of shunt capacitor (SC) banks and the optimal reconfiguration via the proposed algorithm) is appropriate for energy saving compared with different strategies for energy saving, which included distributed generation (DG) at different cost levels.
Mohamed Mohamed; Ziad Ali; Mahrous Ahmed; Saad Al-Gahtani. Energy Saving Maximization of Balanced and Unbalanced Distribution Power Systems via Network Reconfiguration and Optimum Capacitor Allocation Using a Hybrid Metaheuristic Algorithm. Energies 2021, 14, 3205 .
AMA StyleMohamed Mohamed, Ziad Ali, Mahrous Ahmed, Saad Al-Gahtani. Energy Saving Maximization of Balanced and Unbalanced Distribution Power Systems via Network Reconfiguration and Optimum Capacitor Allocation Using a Hybrid Metaheuristic Algorithm. Energies. 2021; 14 (11):3205.
Chicago/Turabian StyleMohamed Mohamed; Ziad Ali; Mahrous Ahmed; Saad Al-Gahtani. 2021. "Energy Saving Maximization of Balanced and Unbalanced Distribution Power Systems via Network Reconfiguration and Optimum Capacitor Allocation Using a Hybrid Metaheuristic Algorithm." Energies 14, no. 11: 3205.
The paper is concerned with designing an effective controller for a linear tubular homopolar (LT-H) motor type. The construction and operation of the LT-H motor are first described in detail. Then, the motor model is represented in the direct-quadrature (d-q) axes in order to facilitate the design of the control loops. The designed control system consists of two main loops: the current control loop and velocity adaptation loop. The determination of the regulator’s gains is accomplished through deriving and analyzing the transfer functions of the loops. To enhance the system’s robustness, a robust variable estimator is designed to observe the velocity and stator resistance. Different performance evaluation tests are performed using MATLAB/Simulink software to validate the controller’s robustness for variable-speed operation and load force changes as well. The obtained results reveal the appropriate dynamics of the motor thanks to the well-designed control system.
Mahmoud Mossa; Hamdi Echeikh; Ziad Ali; Mahrous Ahmed; Saad Al-Gahtani; Hamdy Sultan. Design and Modeling of a Robust Sensorless Control System for a Linear Permanent Magnet Synchronous Motor. Electronics 2021, 10, 966 .
AMA StyleMahmoud Mossa, Hamdi Echeikh, Ziad Ali, Mahrous Ahmed, Saad Al-Gahtani, Hamdy Sultan. Design and Modeling of a Robust Sensorless Control System for a Linear Permanent Magnet Synchronous Motor. Electronics. 2021; 10 (8):966.
Chicago/Turabian StyleMahmoud Mossa; Hamdi Echeikh; Ziad Ali; Mahrous Ahmed; Saad Al-Gahtani; Hamdy Sultan. 2021. "Design and Modeling of a Robust Sensorless Control System for a Linear Permanent Magnet Synchronous Motor." Electronics 10, no. 8: 966.
Shunt active power filters (APFs) are used to address power quality issues such as harmonic distortion and power system imbalance. Many control systems for shunt APFs demand measurements of voltages and currents for the determination of instantaneous real and reactive power signals. From these signals, the reference currents of the shunt APF are calculated. A method of control for the APF shunt that only measures currents is proposed in this paper. The control method includes a modified technique to extract the positive and negative sequence components in the time domain. The reference currents in the shunt APF are calculated by the negative sequence components of the measured currents. Simulation and experimental results confirm the efficiency of this control scheme under ideal and non-ideal conditions.
Saad F. Al-Gahtani; R. M. Nelms. Performance of a Shunt Active Power Filter for Unbalanced Conditions Using Only Current Measurements. Energies 2021, 14, 397 .
AMA StyleSaad F. Al-Gahtani, R. M. Nelms. Performance of a Shunt Active Power Filter for Unbalanced Conditions Using Only Current Measurements. Energies. 2021; 14 (2):397.
Chicago/Turabian StyleSaad F. Al-Gahtani; R. M. Nelms. 2021. "Performance of a Shunt Active Power Filter for Unbalanced Conditions Using Only Current Measurements." Energies 14, no. 2: 397.
The propagation of nonlinear loads and distributed power generation systems can cause power quality problems such as harmonic distortion, system imbalance, and resonance problems. Shunt active power filters are used to eliminate these power quality problems. A recently proposed control scheme for a shunt active power filter utilized a time-domain transformation to extract positive and negative sequence components of the system voltages and currents. These components are used in a modified version of instantaneous reactive power theory to calculate the reference currents for a three-phase inverter. Changes in the system operating conditions can cause the system frequency to vary, which can impact the performance of the time-domain transformation. Proposed in this paper is a frequency adaptive control scheme to compensate for frequency variations. Several simulation and experimental tests have been performed to validate the operation of the proposed frequency adaptive control scheme.
Saad F. Al-Gahtani; R. M. Nelms. A frequency adaptive control scheme for a three-phase shunt active power filter. Electrical Engineering 2020, 103, 595 -606.
AMA StyleSaad F. Al-Gahtani, R. M. Nelms. A frequency adaptive control scheme for a three-phase shunt active power filter. Electrical Engineering. 2020; 103 (1):595-606.
Chicago/Turabian StyleSaad F. Al-Gahtani; R. M. Nelms. 2020. "A frequency adaptive control scheme for a three-phase shunt active power filter." Electrical Engineering 103, no. 1: 595-606.
The presence of power electronics devices on the power grid can cause power quality problems such as harmonic distortion and power system unbalance. Shunt active power filters can be employed to eliminate these power quality problems. Some control systems for the filters do not operate effectively under unbalanced power system conditions. Traditional methods of extracting the signals utilized in instantaneous reactive power theory (IRPT) have weak performance under unbalanced conditions. Therefore, a new extraction method is introduced with improved performance under unbalanced conditions. An improved control method, based on the proposed extraction method, is also presented. Simulation and experimental results validate the improved performance of this control method.
Saad Al-Gahtani; R. M. Nelms. A Modified IRPT Control Method for a Shunt Active Power Filter for Unbalanced Conditions. 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE) 2019, 720 -727.
AMA StyleSaad Al-Gahtani, R. M. Nelms. A Modified IRPT Control Method for a Shunt Active Power Filter for Unbalanced Conditions. 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE). 2019; ():720-727.
Chicago/Turabian StyleSaad Al-Gahtani; R. M. Nelms. 2019. "A Modified IRPT Control Method for a Shunt Active Power Filter for Unbalanced Conditions." 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE) , no. : 720-727.
Shunt active power filters (APFs) are utilized to correct power quality problems such as harmonic distortion and power system unbalance. Many control schemes for shunt APFs require measurement of both voltages and currents for the calculation of the instantaneous real and reactive power signals. The reference currents for the inverter in the APF are determined from these signals. Proposed in this paper is a voltage sensorless control method for a shunt APF which requires that only currents be measured. The reference currents for the inverter in the shunt APF are determined from the negative sequence components of these measured currents. Simulation and experimental results validate the performance of this control method even in the presence of unbalanced conditions.
Saad Al-Gahtani; R. M. Nelms. A New Voltage Sensorless Control Method for a Shunt Active Power Filter for Unbalanced Conditions. 2019 IEEE International Conference on Environment and Electrical Engineering and 2019 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe) 2019, 1 -6.
AMA StyleSaad Al-Gahtani, R. M. Nelms. A New Voltage Sensorless Control Method for a Shunt Active Power Filter for Unbalanced Conditions. 2019 IEEE International Conference on Environment and Electrical Engineering and 2019 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe). 2019; ():1-6.
Chicago/Turabian StyleSaad Al-Gahtani; R. M. Nelms. 2019. "A New Voltage Sensorless Control Method for a Shunt Active Power Filter for Unbalanced Conditions." 2019 IEEE International Conference on Environment and Electrical Engineering and 2019 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe) , no. : 1-6.