• Proceedings of the KIEE Conference
• /
• 1992.07a
• /
• pp.211-213
• /
• 1992

Fuzzy L. P. with Multi-criteria function is adopted in this VAR allocation algorithm to accomplish the optimization of co-conflicting objectives, such as the amount of the VAR Installed and power system loss, while keeping the bus voltage profile within an admissible range. fuzzy L. P., a powerful tool dealing with the fuzziness of satisfaction levels of the constraints and the goal of objective functions, enables us to search for the solutions which may contribute in VAR planning. This advantage Is not provided by traditional standardized L. P. The effectiveness of the proposed algorithm has been verified by the test on the IEEE-30 bus system.

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

• Journal of Computing Science and Engineering
• /
• v.7 no.1
• /
• pp.30-43
• /
• 2013

Multicore and multiprocessor systems with dynamic voltage scaling architectures are being used as one of the solutions to satisfy the growing needs of high performance applications with low power constraints. An important aspect that has propelled this solution is effective task/application scheduling and mapping algorithms for multiprocessor systems. This work proposes an energy aware, offline, probability-based unified scheduling and mapping algorithm for multiprocessor systems, to minimize the number of processors used, maximize the utilization of the processors, and optimize the energy consumption of the multiprocessor system. The proposed algorithm is implemented, simulated and evaluated with synthetic task graphs, and compared with classical scheduling algorithms for the number of processors required, utilization of processors, and energy consumed by the processors for execution of the application task graphs.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.485-488
• /
• 2002

DC-DC converter for KOMPSAT 2 has been designed to satisfy input current, and output voltage ripples constraints, in this paper. The converter has been simulated to analyze small signal characteristics. The resulted phase margin of the converter is above $60^{\circ}$. The DC-DC converter has been experimented for 93kHz, 90W output load.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.129-132
• /
• 1987

This paper presents an emergency control algorithms for viability crisis following abnormal condition as well as a sudden major supply outage and line outage. The algorithm considers the effect of voltage-reactive power control for determining the load shedding quantities and generation reallocation. The problem is decomposed into a P-problem and a Q-problem. The former minimizes system frequency deviation from nominal value and the latter minimizes voltages violation of load buses. The optimization problem is solved by a reduced gradient technique which can handle a great number of inequality constraints very efficiently. It has been found that the use of the proposed algorithm for 6-Bus system restore the abnormal system during the viability crisis to the normal state.

• Proceedings of the KIEE Conference
• /
• 2003.07a
• /
• pp.396-398
• /
• 2003

This paper presents the scheme for load model based dispersed generation system (DGs) installation and operation in unbalanced distribution systems. Groups of each individual load model consist of residential, industrial, commercial, official and agricultural load. The main idea of solving fuzzy nonlinear goal programming is to transform the original objective function and constraints into the equivalent multiple objective functions with fuzzy sets to evaluate their imprecise nature for the criterion of power loss minimization, the number or total capacity of DGs and the bus voltage deviation, and then solve the problem using genetic algorithms. The method proposed was applied to IEEE 13 bus test systems to demonstrate its effectiveness.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.51 no.3
• /
• pp.118-126
• /
• 2002

AVR parameter tuning for voltage control of generators has generally been done with the off-line open-circuit model of the synchronous generator. When the generator is connected on-line and operating with load the AVR operates in an entirely different environment from the open-circuit conditions. This paper describes a new method for AVR parameter tuning for on line conditions using SQP(Sequential Quadratic Programming) meshed with frequency response characteristics of linearized on-line system model. As the proposed method uses the un - line system model the tuned parameter sets show more optimal behavior in the on-line operating conditions. furthermore, as this method considers the performance indices that are needed for stable operation as constraints, AVR parameter sets that are tuned by this method could guarantee the stable performance, too.

• Proceedings of the KIEE Conference
• /
• 1998.07c
• /
• pp.911-914
• /
• 1998

This paper presents an algorithm that evaluates the transfer capability of composite power systems using probabilistic approaches. The reliability indices calculated by using probabilistic method are expected maximal flow, expected transfer capability margin, and expected power not supplied. In this paper, a successive linear programming technique is used to evaluate transfer capability named maximal flow. Physical constraints considered in the maximal flow problem are the limits of toad voltage, line overloading, and real & reactive power generation. Numerical results on IEEE RTS show that the proposed algorithm is effective and useful.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.500-502
• /
• 1995

Whenever faults(a fault) occur(s) in a particular section of a distribution system, some of loads get disconnected and are left unsupplied. Service should be restored to these affected load points as quickly as possible through network reconfiguration. An efficient technique is presented in this paper for this purpose. Network reduction and strategy testing the voltage and current constraints are the main contributions of this paper.

• Journal of the Korea Society of Computer and Information
• /
• v.3 no.4
• /
• pp.63-69
• /
• 1998

The area optimization of the power distribution network is an important problem in the layout design of VLSI systems. In this paper we propose noval methods to solve the problem of designing minimal area power distribution nets, while satisfying voltage drop and electromigration constraints. We propose two novel greedy heuristics for power net design-one based on bottom-up tree construction using greedy merging and the other based on top-down linearly separable partitioning.