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Tahir Khurshaid,Chang-Hwan Kim,Abdul Wadood,Sang-Bong Rhee 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.10
With the expanding size of the power system, there is a certain way of finding solutions to maximize the utilization of existing systems and to provide adequate voltage support. For this, power flexibility is needed. A flexible AC transmission system (FACTS), if located optimally, can be useful in providing voltage support and controlling power flow, which in turn results in lower losses in deregulated power system. This paper proposes a method of finding the optimal location of unified power flow controller (UPFC) to relieve congestion using a sensitivity analysis approach by the Fast de-coupled methodology. The impact of these gadgets on line flows and bus voltage profiles has been studied by placement at the line which is the most positive sensitive or more negative sensitive location and placing them optimally with optimal ratings dictated by sensitivity analysis, in order to reduce losses and improve the voltage profile. The effectiveness of the developed algorithm has been tested on an IEEE 14-bus system.
Tahir Khurshaid,Abdul Wadood,Saeid Gholami Farkoush,김창환,조남훈,이상봉 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1
The coordination of directional overcurrent relays (DOCR) plays a very important role for maintaining security and enhancing reliability in the electrical power system. This paper presents the coordination of directional overcurrent relay using the modified particle swarm optimization (MPSO) technique. In order to improve the quality of a solution a local search algorithm is embedded to the original particle swarm optimization (PSO). Time dial settings had been optimized for directional overcurrent relays. In PSO technique on implementing the DOCR, being a highly constrained optimization problem that takes into consideration the linear programming. To handle such constraints a modification to PSO algorithm has been introduced. MPSO has achieved a lot of relaxation to its easy implementation, modesty and robustness. The proposed algorithm had been tested on IEEE 6-bus, IEEE 15-bus system and IEEE 30-bus system using MATLAB computer programming.
Gholami Farkoush, Saeid,Khurshaid, Tahir,Wadood, Abdul,Kim, Chang-Hwan,Kharal, Kumail Hassan,Kim, Kyu-Ho,Cho, Namhun,Rhee, Sang-Bong Hindawi Limited 2018 Complexity Vol.2018 No.-
<P>A large number of electromagnetic transient studies have been analyzed for finding the overvoltage behavior of power system. A grounding grid of power system is so important for reducing the effect of overvoltage phenomena during a short-circuit event. Two sections are important in grounding system behavior: soil ionization and inductive behavior; this paper focuses on the inductive manner of grounding grid. The grounding grid is considered as a conductor segment; each conductor segment acts as a grounding unit. In this paper, the transient methodology is introduced to investigate the lightning effect on grounding body at each point of grounding grid in normal and optimized conditions. Genetic algorithm is applied for regular and irregular grounding grid to obtain best values of mesh size with the lower ground potential rise (GPR) as compared with the normal condition for more safety. The grounding grid is a combination of inductance, resistance, and capacitance. This model is suitable for practical applications related to fault diagnosis. Several voltages on different positions of grounding grid are described in this paper using ATP-EMTP and genetic algorithm. The computer simulation shows that the proposed scheme is highly feasible and technically attractive.</P>
Gray Wolf Optimizer for the Optimal Coordination of Directional Overcurrent Relay
Chang-Hwan Kim,Tahir Khurshaid,Abdul Wadood,Saeid Gholami Farkoush,Sang-Bong Rhee 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.3
The coordination of directional overcurrent relay (DOCR) is employed in this work, considering gray wolf optimizer (GWO), a recently designed optimizer that employs the hunting and leadership attitude of gray wolves for searching a global optimum. In power system protection coordination problem, the objective function to be optimized is the sum of operating time of all the main relays. The coordination of directional overcurrent relays is formulated as a linear programming problem. The proposed optimization technique aims to minimize the time dial settings (TDS) of the relays. The calculation of the Time Dial Setting (TDS) setting of the relays is the core of the coordination study. In this article two case studies of IEEE 6-bus system and IEEE 30-bus system are utilized to see the efficiency of this algorithm and the results had been compared with the other algorithms available in the reference and it was observed that the proposed scheme is quite competent for dealing with such problems. From analyzing the obtained results, it has been found that the GWO approach provides the most globally optimum solution at a faster convergence speed. GWO has achieved a lot of relaxation due to its easy implementation, modesty and robustness. MATLAB computer programming has been applied to see the effectiveness of this algorithm.
Gray Wolf Optimizer for the Optimal Coordination of Directional Overcurrent Relay
Kim, Chang-Hwan,Khurshaid, Tahir,Wadood, Abdul,Farkoush, Saeid Gholami,Rhee, Sang-Bong The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.3
The coordination of directional overcurrent relay (DOCR) is employed in this work, considering gray wolf optimizer (GWO), a recently designed optimizer that employs the hunting and leadership attitude of gray wolves for searching a global optimum. In power system protection coordination problem, the objective function to be optimized is the sum of operating time of all the main relays. The coordination of directional overcurrent relays is formulated as a linear programming problem. The proposed optimization technique aims to minimize the time dial settings (TDS) of the relays. The calculation of the Time Dial Setting (TDS) setting of the relays is the core of the coordination study. In this article two case studies of IEEE 6-bus system and IEEE 30-bus system are utilized to see the efficiency of this algorithm and the results had been compared with the other algorithms available in the reference and it was observed that the proposed scheme is quite competent for dealing with such problems. From analyzing the obtained results, it has been found that the GWO approach provides the most globally optimum solution at a faster convergence speed. GWO has achieved a lot of relaxation due to its easy implementation, modesty and robustness. MATLAB computer programming has been applied to see the effectiveness of this algorithm.
Distribution Side Load Monitoring, Control and Theft Detection
Kumail Hassan Kharal,Chang-Hwan Kim,Tahir Khurshaid,Sang-Bong Rhee 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.10
Load management and electricity theft on the distribution side are one of the major problems of electrical power systems. This paper presents a novel technique used to eradicate load management and electricity theft detection problems by designing a working model named “Distribution Side Load Monitoring, Control and Theft Detection”. This model consists of three modules: Main module, Consumer module and Relay module. A microcontroller ‘ATmega8’ is the main part of these modules. The Proteus Design Suite was used for the simulation and printed circuit board layout. The main module is installed in a substation and has voltage and current sensors that measure the voltage and current of the line that is connected to the consumer through relays. This limits the consumer’s power and detects theft. This module is also connected to a computer through parallel interface. A consumer module is installed in the energy meter. This module measures and monitors load power. A relay module is simply a switching circuit between the main module and consumer module that can turn on or off the consumer supply on main module instructions. The consumer system (consumer module) installed on the electric meter will send its consumption readings to the central server (substation module) for processing and bill computing. The central server (substation module) will also measure the total power being distributed to all consumers. The difference between the two readings must ideally be zero, when no illegal user is attempting to tap power lines assuming the line losses are known. An illegal load in the power line will cause a difference in the distribution and consumption readings. This difference in the two readings warns the power station of the theft status for that power line and accordingly a manual or auto control mechanism is implemented. The effectiveness of this work has been tested on Proteus Design Suite software.