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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Transactions of the Korean Institute of Electrical Engineers P
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Journal DOI :
The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 54, Issue 4 - Dec 2005
Volume 54, Issue 3 - Sep 2005
Volume 54, Issue 2 - Jun 2005
Volume 54, Issue 1 - Mar 2005
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Comparison of Evolutionary Computation for Power Flow Control in Power Systems
Lee, Sang-Keun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 54, issue 2, 2005, Pages 61~66
This paper presents an unified method which solves real and reactive power dispatch problems for the economic operation of power systems using evolutionary computation such as genetic algorithms(GA), evolutionary programming(EP), and evolution strategy(ES). Many conventional methods to this problem have been proposed in the past, but most of these approaches have the common defect of being caught to a local minimum solution. The proposed methods, applied to the IEEE 30-bus system, were run for 10 other exogenous parameters and composed of P-optimization module and Q-optimization module. Each simulation result, by which evolutionary computations are compared and analyzed, shows the possibility of applications of evolutionary computation to large scale power systems.
Contingency Severity Ranking Using Direct Method in Power Systems
Lee, Sang-Keun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 54, issue 2, 2005, Pages 67~72
This paper presents a method to select contingency ranking considering voltage security problems in power systems. Direct method which needs not the detailed knowledge of the post contingency voltage at each bus is used. Based on system operator's experience and knowledge, the membership functions for the MVAR mismatch and allowable voltage violation are justified describing linguistic representation with heuristic rules. Rule base is used for the computation of severity index for each contingency by fuzzy inference. Contingency ranking harmful to the system is formed by the index for security evaluation. Compared with 1P-1Q iteration, this algorithm using direct method and fuzzy inference shows higher computation speed and almost the same accuracy. The proposed method is applied to model system and KEPCO pratical system which consists of 311 buses and 609 lines to show its effectiveness.
Sensorless Vector Control of Induction Motor with HAI Controller
Lee, Jung-Chul ; Lee, Hong-Gyun ; Chung, Dong-Hwa ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 54, issue 2, 2005, Pages 73~79
This paper is proposed hybrid artificial intelligent (HAI) controller based on the vector controlled induction motor drive system. The hybrid combination of fuzzy control and neural network will produce a powerful representation flexibility and numerical processing capability. Also, this paper is proposed speed estimation of induction motor using a closed-loop state observer. The rotor position is calculated through the stator flux position and an estimated flux value of rotation reference frame. A closed-loop state observer is implemented to compute the speed feedback signal. The results of analysis prove that the proposed control system has strong robustness to rotor parameter variation, and has good steady-state accuracy and transitory response.
Design of Robust Adaptive Backstepping Controller for Speed Control of Separately Excited DC Motor
Hyun, Keun-Ho ; Son, In-Hwan ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 54, issue 2, 2005, Pages 80~88
In this paper, an robust adaptive backstepping controller is proposed for the speed control of separately excited DC motor with uncertainties and disturbances. Armature and field resistance, damping coefficient and load torque are considered as uncertainties and noise generated at applying load torque to motor is also considered. It shows that the backstepping algorithm can be used to solve the problems of nonlinear system very well and robust controller can be designed without the variation of adaptive law. Simulation and experiment results are provided to demonstrate the effectiveness of the proposed controller.
The Comparison Study for Voltage, Current and Load Unbalance Factor
Kim, Jong-Gyeum ; Park, Young-Jeen ; Lee, Eun-Woong ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 54, issue 2, 2005, Pages 88~93
Most of the LV customer have been applied the distribution system of 3-phase four wire system because of its advantage of supplying both of 1-phase & 3-phase loads simultaneously. Due to its structural simplicity, it is more convenient for use rather than the conventional separated scheme. But uneven load distribution or unclean voltage quality has occurred various problems such as de-rating, losses increase and vibration, etc. In this paper, voltage, current and power waveform in the actual fields have measured and analyzed in relation with internationally allowable voltage unbalance limits and compared the current unbalance factor with the load unbalance factor.
Analysis of the Data Reliability for the Preventive Diagnostic System
Kweon, Dong-Jin ; Chin, Sang-Bum ; Kwak, Joo-Sik ; Woo, Jung-Wook ; Choo, Jin-Boo ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 54, issue 2, 2005, Pages 94~100
Abnormal symptoms on operating conditions of power transformer are monitored by a preventive diagnostic system which prevents the sudden power failure in case of quick progress of abnormal situation. The preventive diagnostic system helps plan the proper maintenance method according to the transformer conditions via accumulated data. KEPCO has adopted the preventive diagnostic system at nine of 345kV substations since 1997. Application techniques of the diagnostic sensors were settled, but diagnostic algorithm and practical use of accumulated data are not yet established. To build up the diagnostic algorithm and effective use of the preventive diagnostic system, the reliability of the data which were accumulated in a server computer is very important. This paper describes the data analysis in the server in order to advance the reliability of the accumulated data of the preventive diagnostic system. The principles and data flows of the diagnostic sensors were analyzed, and the data discrepancy between sensors and server were calibrated.
Development of Power Supply Device for Load Characteristic Experimentation
Lee, Jong-Pil ; Ji, Pyeong-Shik ; Lim, Jae-Yoon ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 54, issue 2, 2005, Pages 101~107
The reduced power quality due to some of disturbances on power system has great influence on the efficient and life of load for bad with serious economic loss. The response of load about disturbance needs to analysis quantitatively in detail to improve load characteristics. In this research, a power supply device is developed to supply disturbed power similar to that of power system. The developed device can output a voltage and frequency from 180[V] to 240[V], 55[Hz] to 65[Hz] respectively. The most outstanding feature of this device is a function to be performed steady and dynamic state characteristic experiment on load or appliances. Also, this device is designed to include high accuracy ouput and simple measurement.