• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.283-284
• /
• 2011

Generally, it is important to use the regenerative energy efficiently for decrease of inverter's consuming energy. From various industry sector (railroad, steel, crane etc), re-uses the regenerative energy which uses the regenerative converter unit, and gets a many profit from whole consuming energy. In this paper, we introduce development of the regenerative converter unit that supply the regenerative energy to power source and main drive inverter, and introduce the instance which is applied in the elevator.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2002.05a
• /
• pp.101-106
• /
• 2002

In the Refrigeration and air conditioning industrial circles, refrigerator is demands a high degree of efficiency due to the Environmental Preservation Law. Many researchers are working on factors to improve the efficiency of the refrigerator In this paper, a study of the factors on the decrease of electric power consumption, several experiments are performed to improve the fluid flow in the refrigerator machine room. As a results, average temperatures of compressor and condenser are reduced 3.1$^{\circ}C$, 2.$0^{\circ}C$. The consuming electric power rate is reduced 0.7kWh/month.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.8
• /
• pp.3086-3101
• /
• 2021

To supply precise marketing and differentiated service for the electric power service department, it is very important to predict the customers with high sensitivity of electric power failure. To solve this problem, we propose a novel grouped 𝑙_1/2 sparsity constrained logistic regression method for sensitivity assessment of electric power failure. Different from the 𝑙₁ norm and k-support norm, the proposed grouped 𝑙_1/2 sparsity constrained logistic regression method simultaneously imposes the inter-class information and tighter approximation to the nonconvex 𝑙₀ sparsity to exploit multiple correlated attributions for prediction. Firstly, the attributes or factors for predicting the customer sensitivity of power failure are selected from customer sheets, such as customer information, electric consuming information, electrical bill, 95598 work sheet, power failure events, etc. Secondly, all these samples with attributes are clustered into several categories, and samples in the same category are assumed to be sharing similar properties. Then, 𝑙_1/2 norm constrained logistic regression model is built to predict the customer's sensitivity of power failure. Alternating direction of multipliers (ADMM) algorithm is finally employed to solve the problem by splitting it into several sub-problems effectively. Experimental results on power electrical dataset with about one million customer data from a province validate that the proposed method has a good prediction accuracy.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.3365-3370
• /
• 2007

We developed micro power generation system using piezoelectric materials. In our system, the ambient vibrating energy is converting to electric energy by deflection of piezoelectric beams. The system consists of energy generating parts, converting enhancement parts, electric regulation and charging parts, and interface with small-energy-consuming mobile devices. The geometry of piezoelectric beams, the source of vibrating energy, and the electric load of target application determine the characteristics of generating electric power, such as impedance, voltage, current and power density. Therefore, we made a model for analysis of generating power with given information such as piezoelectric materials, geometry, vibration type, and mass. With this model, we can calculate capacitance of piezoelectric beams, generating voltage, current, and power. To obtain maximum energy transfer efficiency, we approached this study in the view of material, electrical, and mechanical engineering

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.57 no.4
• /
• pp.400-403
• /
• 2008

In this work, an individual trespassing detector using a PIR sensor to detect infrared rays only between the range of $9.4{\sim}10.4{\mu}m$ radiated from the body is proposed. This detector using FIR sensor detects not insect or object but human body, It doesn't restrict the inhabitant's behavior because the filter of pm sensor is designed to have face angle and the detector only detects the window area. The existing wide angle filter, RIR sensor, detects $30^{\circ}$ angle while the face angle filter sensor on this paper detects $11^{\circ}$ angle with 3cm of face angle filter from 2m of detecting distance. In case of interruption of electric power, 250mAh of lithium-ion battery has worked for 10 hours consuming 22mA in normal state. Meanwhile, in case of interruption of electric power, 250mAh of battery has worked for 4 hours consuming 60mA in trespassing detecting state. Projector, receptor, controller and alarm are put on one PCB in order to make it convenient to install without any special installation skill.

• Proceedings of the KIEE Conference
• /
• 1993.07a
• /
• pp.205-207
• /
• 1993

Distribution planning requires comprehensive knowledge about not only distribution but also transmission/subtransmission system expansion plan. At the same time, distribution planning is very time consuming and a series of routine job which involves a lot of experience and efforts of planning engineers. Since the quality of distribution planning depends upon the ability of planning engineers, the economy of investment should be taken into consideration. The object of this study is to establish a computerized distribution planning system which helps distribution engineers finding a new system expansion plan. It provides the engineers with at optimal system expansion plan which satisfies the condition of both reliability and economy.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.2
• /
• pp.568-579
• /
• 2018

Virtual power plants can be regarded as systems that have entered the network after restructure of power systems. In fact, these plants are a set of consumers capable of consuming and generating power. In response to widespread implementation of plug-in hybrid electric vehicles, further investigation of energy management in this type of power plants seems to be of great value. In effect, these vehicles are able to receive and inject power from/into the network. Hence, study of the effects of these vehicles on management of virtual power plants seems to be illuminative. In this paper, management of power consumption/generation in virtual power plants has been investigated in the presence of hybrid electric vehicles. The objective function of virtual power plants problem management is to minimize the overall costs including not only the costs of energy production in power generation units, fuels, and degradation of batteries of vehicles, but also the costs of purchasing electricity from the network. Furthermore, the constraints on the operational of plants, loads and hybrid vehicles, level of penalty for greenhouse gas emissions ($CO_2$ and $NO_x$) produced by power plants and vehicles, and demand response to the immediate price of market have all been attended to in the present study. GAMS/Cplex software system and sample power system have been employed to pursue computer implementation and simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.1
• /
• pp.70-77
• /
• 2011

Sewage treatment plants, consuming 1,756[GWh] which is 0.53[%] of national wide electricity consumption, is one of the electricity consuming facilites. At the research of electricity consumption and power quality analysis on sewage treatment plants, average utilization of transformer was less than 40[%] because peak load was very lower than its capacity due to excess capacity. So reduction of power loss can be achieved by transformer design optimization. The achievement in this research, is to meet reduction of power loss through optimizing the capacity and to improve as high efficiency-low loss transformer while the transformer is operating.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.05a
• /
• pp.378-384
• /
• 2005

This paper presents the prospects of today's situation of Korea Electric Power Industry and future's development direction at the sudden chin international environment Several paradigm,-Deregulated electric market Energy shortage, Green house effect due to $CO_2$, TBT(Technical Barrier to Trade), Digital society-will facilitate the glove to develope new technology based Power Industry. With respect to this change, Korea Power Industry needs to find new technology solutions for the smarter operation, higher efficiency and lower carbon consuming power system based on mid-long term plan.

• Journal of the Korean Data and Information Science Society
• /
• v.20 no.2
• /
• pp.283-292
• /
• 2009

Recently the stable electric power supply is threaten by the rapid development of all the industries consuming a lot of electric power, thus KEPCO is trying to establish the countermeasures to cope with this circumstance of uprising power consumption by running the efficient and flexible 12-month s price policy for the base price and raisin the electric power price remarkably in peak power consumption period to suppress the maximal power demand of consumers. To resolve these problems, this study propose the method calculating hourly CBL based on the hourly amount at non-event using the pattern of the amount of power consumption and propose the operation method of DR Program.