• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.11B no.3
• /
• pp.98-103
• /
• 2001

This paper presents the numerical analysis of piezoelectric devices using three-dimensional finite element analysis. The characteristic of piezoelectric transducer, such as mechanical displacement and electrical are analyzed and the validity is confirmed by experiments Applying the finite element routine to a piezoelectric transformer, the resonance features electrical impedance. the ratio of step-up voltage and vibration mode of piezoelectric transformer are calculated numerically By using three-dimensional finite element method effects of width variation to resonance features, electrical input impedance and the voltage step-up ratio for a piezoelectric transformer, can be considered in design procedure.

• Proceedings of the KIEE Conference
• /
• 2007.11b
• /
• pp.187-189
• /
• 2007

This paper presents the development method of educational simulator for Power System Analysis. The developed simulator can be made the students to model, analysis of power systems by drawing the system and performing the load flow, fault analysis by themselves under window environment. The simulator has developed by using the language based on XML(extensible Markup Language). Therefore, we determine that this simulator is useful to educate the load flow and fault analysis.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2060-2062
• /
• 1999

When the high voltage is applied on insulation materials that have voids and impurities inner one, then probability of electrical tree inception is increased at defects. Electrical tree gives a profit to degradation analysis, because it is possible to observe by eyes and provides electrical degradation step. And electrical tree is divided to three types in usual - tree type, bush type and chestnut type tree. But these three types are divided not by method of quantitative analysis but visual and experiential analysis. In this paper, three types of electrical tree were calculated by quantitative analysis using fractal mathematics and classified to fractal dimensions (FD). FD of tree types are 1.1$\sim$1.4, bush types are 1.4$\sim$1.6 and chestnut type trees have above 1.6 FD.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.68 no.1
• /
• pp.36-43
• /
• 2019

In this paper, the characteristics of the coaxial magnetic gear according to the shape of the same gear ratio are analyzed using the two - dimensional finite element analysis. The rotor shape is SMCMG, CPCMG and RCMG. After this we analyzed the characteristics according to three shapes. Also, the amount of permanent magnet used in each shape was compared. Next, characteristics analysis of the magnetic gear according to the shape at the same torque was performed. And the total weight and efficiency of the magnetic gears were compared and verified.

• Journal of Electrical Engineering and Technology
• /
• v.1 no.2
• /
• pp.145-152
• /
• 2006

This paper presents a windows application for voltage sag analysis and effective data visualization. The developed Voltage Sag Analysis Tool (VSAT) was designed by using the Object-Oriented Programming (OOP) concept and C++ programming language. The VSAT provides basic functions for voltage sag analysis such as power flow analysis, short circuit analysis and stochastic analysis. In particular, the VSAT provides effective data visualization through computer graphics and animation. Analysis results are expressed realistically and intuitively on geographical display. The Graphic User Interface (GUI) of VSAT was designed specifically for voltage sag analysis. In this paper, the development and implementation of VSAT is presented. In order to demonstrate the capabilities of VSAT, it is used to analyze the Jeju Island power system in South Korea.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.11
• /
• pp.1931-1936
• /
• 2016

In this paper, we analyzed causes of accidents that recently increased in the illegal and defective LED lamps. They were analyzed by the electrical characteristics calculation and reappearance experiments. The causes of the accidents were analyzed from the circuit affected by the variation of voltage, current and power by harmonics. We drew a conclusion for electrical safety in illegal or degraded LED lamps from the analysis result. The management factors for electrical safety in LED lamps were harmonics, reactive power and power factor. It is possible to secure the electrical safety through monitoring of power factor in failure products and available in smart meters or smart distribution boards.

• Proceedings of the KIEE Conference
• /
• 2009.04b
• /
• pp.58-60
• /
• 2009

This paper deals with force characteristic analysis of linear switched reluctance motor using dynamic simulation. First, we calculated flux density of linear switched reluctance motor according to position. Second, analyzed normal force from flux density of linear switched reluctance motor according to position. Also, analysis result compares with data that is derived through a finite element analysis, and proved validity. However, linear switched reluctance motor has non linear characteristic, hence, analysis of propulsion force do not easy using analytical method. Therefore, we presented dynamic characteristic analysis model which is consisted at motor and sensor signal part, etc., and substitute circuit constant that get using magnetic equivalent circuit method, we confirmed propulsion force.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1112-1114
• /
• 2004

In the year 2002, 11,202 cases of electrical fires caused 462 casualties and about 58 billion won of physical damages. The electrical accidents alone caused victimized 854 people, including 87 deaths. at present, no detailed statistics about electrical fires is available. Also, there is no statistics about electric shocks and electrical equipment accidents. the electrical accidents are on the increase, proportional to the increase of electrical use. Therefore, a statistical analysis of electrical accidents is required to understand the situation and take measures to prevent similar accidents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.615-618
• /
• 2003

To investigate the electrical fire identification due to conductor structure analysis of an electrical wire, we are studied by temperature heating test, over current test, short test and electric molten marks. And metal structure analysis of wire by short, we are found out increase in crystal grain with heating temperature. Structure of specimen at over current 300[%] occurred hardly structure formation and boundary of grain.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.12
• /
• pp.88-96
• /
• 2015

This paper describes a new method for enhancing the accuracy of network analysis applications in energy management systems. Topology processing, state estimation, power flow analysis, and contingency analysis play a key factor in the stable and reliable operation of power systems. In this respect, the aim of topology processing is to provide the electrical buses and the electrical islands with the actual state of the power system as input data. The results of topology processing is used to input of other applications. New method, which includes the topology error analysis based on inconsistency check, coherency check, bus mismatch check, and outaged device check is proposed to enhance the accuracy of network analysis. The proposed methodology is conducted by energy management systems and the Korean power systems have been utilized for the test systems.