• Journal of Electrical Engineering and Technology
• /
• v.12 no.1
• /
• pp.225-229
• /
• 2017

This paper describes the loss analysis based on load conditions of the air conditioning compressor motors using variable dc-link voltage. The losses of PMSM (Permanent Magnet Synchronous Motor) should be analyzed by the PWM (Pulse Width Modulation) output of inverter. The harmonic loss by the PWM cannot consider that using the current source analysis of the inverter. In addition, when the voltage of dc-link is variable with the condition of variable speed and load conditions in motor, the losses of motor are also changeable, however it is hard to analyze those losses by only electromagnetic finite element method (FEM). Therefore, this paper proposes the analysis method considering the carrier frequency of the inverter and the varying state of the dc-link voltage through the FEM-control coupled analysis. Using proposed analysis method, additional core loss and eddy current loss of permanent magnet caused by PWM could be analyzed. Finally, the validity of the proposed analysis method is verified through the comparison the result of coupled analysis with experiment.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.2
• /
• pp.349-352
• /
• 2015

This paper estimates electrical fire damage cost-effect to analyze electrical safety efficiency by applying a cost-benefit analysis method for analyzing the efficiency of a business public interest. Electrical fire loss statistics data was presented as direct costs and casualties, including deaths due to an electrical fire, this paper adds overhead "Incidental Cost of Accidents to the Employer" by W. H. Heinrich was applied to estimate the cost of economic loss. Also wounded, including the loss of human deaths by referring to the car accident insurance claims costs and human development estimated the losses caused by an electrical fire. And to perform a cost-benefit analysis of the electrical safety as a result of future work. In this paper, the economic effect of the electric field of safety and public interest work to systematically presented.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.8
• /
• pp.1317-1325
• /
• 2016

This paper identifies the issues of contingency analysis for restoration in distribution systems. Contingency analysis has been applied to transmission systems but not to distribution systems. The distribution system is different from transmission system. So it is hard to apply for existing contingency analysis to distribution system. In this paper, a new contingency analysis method for distribution systems is proposed. The proposed method is based on service restoration capability. It aims to minimize outage left after service restoration in case of a fault in advance. The method estimates the vulnerability which is represented by zone restoration index proposed in [1]. Applying the proposed method, operators could change the system so that it does not leave any outage left after restoration. Case study has been carried out on a five feeder system and its results show effectiveness of the method.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.5
• /
• pp.1282-1288
• /
• 2016

• Fire Science and Engineering
• /
• v.16 no.3
• /
• pp.56-60
• /
• 2002

Recently, with the growth of software for electro-thermal analysis, it has been studied the precise analysis and investigation of cause for the electrical fire using computer simulation on the basis of theory for electro-thermal analysis. But it is very lacking for the precise analysis and investigation of cause for the electrical fire. In this paper, we have simulated the thermal analysis for electrical wire according to the value of current in a overload and a short with the electrical wire of the L's company product(600 V VVF) using the electro-thermal finite element method(Flux2D).

• International Journal of Safety
• /
• v.6 no.2
• /
• pp.17-21
• /
• 2007

This paper aims at the statistical analysis of electrical fire and classification of electrical fire causes to collect electrical fires data efficiently. Electrical fire statistics are produced to monitor the number and characteristics of fires attended by fire fighters, including the causes and effects of fire so that action can be taken to reduce the human and financial cost of fire. Electrical fires make up the majority of fires in Korea(including nearly 30% of total fires according to recent figures), The incorrect and biased knowledge for electrical fires changed the classification of certain types of fires, from non-electrical to electrical. It is convenient and required to develop the standardized form that makes, in the assessment of the cause of electrical fires, the fire fighters directly ticking the appropriate box on the fire report form or making an assessment of a text description. Therefore, it is highly recommended to develop electrical fire cause classification and electrical fire assessment on the fire statistics in order to categorize and assess electrical fires exactly. In this paper newly developed electrical fire cause classification structure, which is well-defined hierarchical structure so that there are not any relationship or overlap between cause categories, is suggested. Also fire statistics systems of foreign countries are introduced and compared.

• Journal of the Korean Society of Safety
• /
• v.22 no.4
• /
• pp.26-31
• /
• 2007

According to the statistical analysis on the electrical fire of 2005 years, most of electrical fire is generated from short circuit(4,985 cases), overcurrent(755 cases) leakage current(391 cases), poor contact(378 cases), disconnection(36 cases) on the electrical wiring device. The researches for the fire hazard about normal electric wiring have already been progressing in the advanced country such as USA and Japan, but Comparative study of the disconnection has not been conducted. Therefore, in this paper, we have simulated the thermal analysis for electrical wire according to deteriorating time in a normal state and disconnection with electrical wire using the electrical-thermal finite element method(Flux 3D). This paper acquire basis data of electricity fire signal by disconnection and wish to help for electrical fire cause diagnosis business.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.5
• /
• pp.1116-1121
• /
• 2013

Mechanical imbalances are common mechanical faults in induction motors. Vibration monitoring techniques have been widely used for the diagnosis of mechanical faults in induction motors, but electrical detection methods have been preferred in recent years. For many years, researchers have concentrated on the Motor Current Signature Analysis (MCSA). This paper examines the effect of mechanical imbalances to induction machine electrical parameters. Instantaneous Power Signature Analysis (IPSA) technique used to detect these faults. In the paper, a full analysis of the proposed technique is presented, and experimental results for healthy and faulty motors have been shown and discussed.

• Proceedings of the KIEE Conference
• /
• 1997.07a
• /
• pp.168-170
• /
• 1997

This paper presents the dynamic analysis of a reciprocating actuation system based on moving magnet actuator for gas compression. For the analysis of the linear actuator, an axisymmetric finite element method (FEM) considering the saturation effect of the magnetic material is used, and electrical circuit equation, mechanical dynamic equation and pressure dynamics are coupled. In the FE analysis, we adopt a moving line technique. The pressure dynamics of the gas in the compressor is modeled by using the law of thermodynamics. The analysis results are compared fairly well with experimental ones.

• Proceedings of the KIEE Conference
• /
• 1999.07a
• /
• pp.164-166
• /
• 1999

In this study, dynamic analysis of Linear DC motor has been performed. Dynamic characteristic is carried out from coupling the electrical circuit equation and mechanical kinetic equation. Trust constant and circuit parameters are obtained by FE analysis and static characteristic experiment. From the previous results, dynamic analysis is performed and the appropriateness of analysed result is verified by comparing with experimental result.