• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.7
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• pp.839-846
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• 1999

This paper presents an efficient algorithm for determining the location, size and number of capacitors in unbalanced radial distribution system. The objective function formulated consists of two terms: cost for energy loss and cost related to capacitor purchase and capacitor installation. The cost function associated with capacitor placement is considered as step function due to banks of standard discrete capacities. Genetic algorithms(GA) are used to obtain the population is derived. The strings in each population consist of the bus number index and size of capacitors to be installed. In order to determine the number of capacitor placement, the length mutation operator is used. Its efficiency is proved through the application in unbalanced radial distribution systems made of 10 buses with 9 distribution lines and 25 buses with 24 distribution lines.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.748-754
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• 2008

The general capacitor placement problem is a combinatorial optimization problem having an objective function composed of power losses and capacitor installation costs subject to bus voltage constraints. In this paper, a global optimization technique, which employing the chaos search algorithm, is applied to solve optimal capacitor placement problem with reducing computational effort and enhancing global optimality of the solution. Chaos method in optimization problem searches the global optimal solution on the regularity of chaotic motions and easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos optimization method is tested on 9 buses and 69 buses system to illustrate the effectiveness of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.6
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• pp.316-324
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• 2003

This paper applied Elite-based Simplex-GA hybrid approach combined with Muptipop-GA (ESGA) to determining the location, size and number of capacitors to improve voltage profile and minimize power losses in unbalanced distribution systems. One of the main obstacles in applying GA to complex problems has been the high computational cost due to their slow convergence rate. To alleviate this difficulty, ESGA approach was developed that combines Elite-based Simplex-GA hybrid approach with Muptipop-GA. The objective function formulated consists of two terms: cost for energy losses and cost related to capacitor purchase and capacitor installation. The cost function associated with capacitor placement is considered as a step function due to banks of standard discrete capacities. Its efficiency was proved through the application in IEEE 13 bus and 34 bus test systems and was compared with several methods using GA.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.124-126
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• 2002

The general capacitor placement problem is a combinatorial optimization problem having an objective function composed of power losses and capacitor installation costs subject to bus voltage constraints. In this paper, the method employing the chaos search algorithm is proposed to solve optimal capacitor placement problem with reducing computational effort and enhancing optimality of the solution. Chaos method in optimization problem searches the global optimal solution on the regularity of chaotic motions and easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos optimization method is tested on 9 buses and 69 buses system to illustrate the effectiveness of the proposed method.

• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.786-792
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• 2011

The present paper presents an optimal capacitor placement (OCP) algorithm for voltagestability enhancement. The OCP issue is represented using a mixed-integer problem and a highly nonlinear problem. The hybrid particle swarm optimization (HPSO) algorithm is proposed to solve the OCP problem. The HPSO algorithm combines the optimal power flow (OPF) with the primal-dual interior-point method (PDIPM) and ordinary PSO. It takes advantage of the global search ability of PSO and the very fast simulation running time of the OPF algorithm with PDIPM. In addition, OPF gives intelligence to PSO through the information provided by the dual variable of the OPF. Numerical results illustrate that the HPSO algorithm can improve the accuracy and reduce the simulation running time. Test results evaluated with the three-bus, New England 39-bus, and Korea Electric Power Corporation systems show the applicability of the proposed algorithm.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.45-51
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• 2014

Distribution system is a critical link between customer and utility. The control of power loss is the main factor which decides the performance of the distribution system. There are two methods such as (i) distribution system reconfiguration and (ii) inclusion of capacitor banks, used for controlling the real power loss. Considering the improvement in voltage profile with the power loss reduction, later method produces better performance than former method. This paper presents an advanced evolutionary algorithm for capacitor inclusion for loss reduction. The conventional sensitivity analysis is used to find the optimal location for the capacitors. In order to achieve a better approximation for the current candidate solution, Opposition based Differential Evolution (ODE) is introduced. The effectiveness of the proposed technique is validated through 10, 33, 34 and85-bus radial distribution systems.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.1-6
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• 2022

The mobile device industry demands much higher levels of integration and lower costs coupled with a growing awareness of the complete system's configuration. A subsystem module package is similar to a board-level circuit that integrates a system function in a package beyond a System-in-Package (SiP) design. It is an advanced IC packaging solution to enhance the PDN and achieve a smaller form factor. Unlike a system-level design with a decoupling capacitor, a subsystem module package system needs to redefine the role of the capacitor and its configuration for PDN performance. Specifically, the design of package's form factor should include careful consideration of optimal PDN performance and the number of components, which need to define the decoupling capacitor's value and the placement strategy for a low impedance profile with associated cost benefits. This paper will focus on both the static case that addresses the voltage (IR) drop and AC analysis in the frequency domain with three specific topics. First, it will highlight the role of simulation in the subsystem module design for the PDN. Second, it will compare the performance of double-sided component placement (DSCP) motherboards with the subsystem module package and then prove the advantage of the subsystem module package. Finally, it will introduce three-terminal decoupling capacitor (decap) configurations of capacitor size, count and value for the subsystem module package to determine the optimum performance and package density based on the cost-effective model.

• Transactions on Electrical and Electronic Materials
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• v.18 no.6
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• pp.345-349
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• 2017

Reconfiguration is an important method to minimize power loss and load interruption by creating an optimal configuration of a system. Furthermore, by increasing demand and value of consumption, construction of new power plants can be postponed in networks by reconfiguration and proper arrangement of linkage switches. This method is feasible for radial networks, which create meshes of linkage switches. One convenient way to achieve a system with minimal power loss and interruption is to utilize capacitors. Optimal placement and sizing of capacitors in such applications is an important issue in the literature. In this paper, cat swarm optimization is introduced as a new metaheuristic algorithm to achieve this purpose. Simulation has been carried out in two feasible networks, 69-bus and 33-bus systems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.164-171
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• 2008

This paper proposes the planning method for placement of capacitors in a distribution system. The main objectives in the planning for capacitor allocation are the reduction of installation costs and electric power loss. In the proposed method, the life time of each device is considered in calculating installation costs, and the optimal operation status of devices is found by genetic algorithm. Then, the optimal numbers and locations are determined based on the optimal operation status. Simulation results in the 69-bus distribution system show that the proposed method performs better than conventional methods.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1009-1011
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• 1997

This paper presents an optimization method which determines locations and size of capacitors simultaneously while minimizing power losses and improving voltage profile in radial distribution systems. Especially, the cost function associated with capacitor placement is considered as step function due to banks of standard discrete capacities. Genetic algorithms(GA) are used to obtain efficiently the solution of the cost function associated with capacitors which is non-continuous and non-differentiable function. The strings in GA consist of the node number index and size of capacitors to be installed. The length mutation operator, which is able to change the length of strings in each generation, is used. The proposed method which determines locations and size of capacitors simultaneously can reduce power losses and improve' voltage profile with capacitors of minimum size. Its efficiency is proved through the application in radial distribution systems.