• 동력기계공학회지
• /
• 제19권4호
• /
• pp.43-49
• /
• 2015

This study has been analyzed and investigated the possibility for the substitution of a heat source with the application of PTC(Positive Temperature Coefficient Heater) in a food drying machine. And this experiment was conducted to measure temperatures at the upper part of the vessel and the heat sink. And the structure has the many holes plane connected with the external air in the upper part of similar volumetric vessel, and attached to the PTC heater (3sets) of total consumption electricity of 120[W] in Al radiant heat structure and the small fan (2sets) in the suitable space of the lower part. Consequently, it was found that at the most conditions of food drying test with the seven holes(5mm) under the control temperature $62^{\circ}C$, the optimum drying condition formatted and the optimum time range especially appeared from 6,500 second to 7,000 second in case of drying test on banana sample.

• 전기학회논문지
• /
• 제64권10호
• /
• pp.1508-1516
• /
• 2015

This paper proposes the optimal operation of ESS (Energy Storage System) in the substation of urban railway in an economical point of view. Since the load patterns of urban railway have different characteristics with the general power demand pattern, the characteristics motivate us to develop the optimal operation algorithm for ESS under Korean electricity billing system. We also introduce two different ESS operation strategies for peak load shaving and electricity consumption charge minimization respectively, and formulate each scheme. Historical data from Namgwangju substation are used for economical comparison of the strategies. The results show that the proposed algorithm is the most cost-effective ESS operation scheme among the strategies and reduces around 5 percent of electric charges compared to the charge without ESS operation.

• 에너지공학
• /
• 제18권3호
• /
• pp.191-202
• /
• 2009

2005년 2월 교토의정서가 효력을 발휘하게 됨에 따라 우리나라는 세계 10위의 이산화탄소 배출국으로서 2013년 이후에는 감축의무를 지어야 할 실정이다. 특히 온실가스 배출량의 약 30%가 발전부문에 의한 것이므로 전환부문의 에너지 소비 저감은 매우 중요하다. 이에 정부는 온실가스 감축환경에 대응하기 위하여 "제1차 국가에너지기본계획"을 발표하여 원전설비를 2030년까지 최대 41%까지 확대하고, 신재생에너지보급률 또한 11%로 높이겠다는 목표를 내세웠다. 이에 근거하여 원자력과 신재생에너지발전설비를 확대하였을 경우 온실가스 저감 잠재량과 그 유효성을 LEAP(Long-range Energy Alternative Planing system)을 이용하여 정량적으로 분석하였다. 분석결과 2030년 기준으로 총 $CO_2$ 발생 저감률은 28.8% 였다. 또한 BAU 시나리오 발전량을 토대로 하였을 때 유연탄발전 $0.85\;kgCO_2/kWh$, LNG발전 $0.51\;kgCO_2/kWh$의 단위 발전량당 온실가스 배출량을 보였다. 따라서 기존설비를 대체할 시, 유연탄발전을 대체할 경우에 온실가스 저감 효과가 크다는 결론을 보였다.

• 한국산학기술학회논문지
• /
• 제18권11호
• /
• pp.138-144
• /
• 2017

오늘날 전력수요 급증에 따른 전력소비량이 증가하고 있어 전력손실을 줄일 수 있는 에너지 저감을 위한 설계 또는 설비 대체로 전력의 고품질화가 필요하다. 배전반이란 한전의 발전설비로부터 전기를 공급받아 각 건물에 필요한 설비에 계통별 또는 용도별로 나누어 주는 기계장치이다. 배전반은 일반적으로 외함, 개폐기, 전력용 도체, 제어부분으로 구성된다. 본 연구는 배전반내의 메인 요소인 통전을 위한 전력용 도체에 관한 것이다. 실효교류저항 측정시험을 통해 기존방식 판상도체의 수직 배열구조가 비효율적 구조임을 입증해 본다. 실효교류저항이 많이 증가하면 표피효과로 인해 상대적으로 도체의 단면적이 커지게 된다. 본 연구는표피효과를 줄여 실효교류저항을 최소화시키는 애스터리스크(*) 배열구조를 기반으로 설계하여 에너지 절약과 원자재 절감을 연구하였다. 본 연구의 핵심기술 원리는 애스터리스크 배열구조를 적용하여 도체저항 감소기술 기반 에너지 절감 수배전반이다. 수배전반의 교류전력 공급용 판상도체 각각(rst 또는 abc)의 상에서 발생한 자기장이 상호작용으로 상쇄 소멸될 수 있도록 한 판상도체 배열구조에 관한 것으로 효과로는 판상도체에서 유도성 리액턴스의 발생량이 줄어들면서 유효단면적이 증가, 실효교류저항을 줄인다.

• 한국컴퓨터정보학회논문지
• /
• 제16권8호
• /
• pp.137-146
• /
• 2011

에너지 소모에 대한 증가되는 소비자의 관심을 지원하기 위하여 가전기기의 에너지 모니터링과 예측 방식을 제안한다. 제안한 시스템은 0.5초마다 전류 센서를 지나가는 전류량을 측정하는 스마트 플러그라는 일반 전기 콘센트로 설계하고, 신경회로망의 훈련과 시험 데이터를 얻기 위해 평균기온, 최저기온, 초고기온, 습도, 일조시간의 날씨 정보를 입력 데이터로 사용하고, 스마트 플러그를 통한 전기 사용량을 목표값으로 사용하였다. 훈련을 위한 실험데이터를 사용하여 역전파 알고리즘을 기반으로 한 신경회로망을 구성하였다. 입력과 출력 데이터의 비선형 매핑을 위해 다층신경회로망을 사용하였다. 제안한 신경회로망 모델은 상관관계 계수가 0.9965로 우수하게 전기 사용량을 예측할 수 있는 것을 확인하였으며, 예측의 평균 제곱 오차는 0.02033이다.

• Journal of Electrical Engineering and Technology
• /
• 제13권2호
• /
• 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.

• 조명전기설비학회논문지
• /
• 제15권6호
• /
• pp.27-34
• /
• 2001

There are several electricity applied sterilizers such as using high frequency, ozone, high voltage, and so on. Those sterilizers feature "because of no chemical process and no secondly environmental pollution". At the power conversion part, ZVS and ZCS methods have been used that it results in reduced switching loss, miniaturized size, and lightened weight. Besides, the current in the propose device is smaller than that of existing method. Thus, it is expected that the cost of sterilization process, when quality of the device is measured by power consumption, will be reduce. Therefore, the purpose of this research is to solve the sterilization problems of existing powder with high voltage and field to and more economical and effective way, and to suggest mere improved sterilizer.

• Current Photovoltaic Research
• /
• 제9권1호
• /
• pp.11-16
• /
• 2021

In the past, marine pollution caused by radioactivity and wastewater discharge caused mass destruction. As an alternative, the land farming system became common and operational. In recent years, safety and environmental problems caused by declining population due to aging of fishermen and underdeveloped facilities have always been lurking, so improvement is urgently needed. As part of the new renewable energy 3020 plan announced by the government in 2017, a new model was proposed to improve the environment as well as save energy when the roof of a water tank farm was remodeled into a solar power system. Study, when the existing roof was remodeled and replaced with a water tank farm in Busan as an empirical model, the energy saving rate was analyzed by comparing the actual electricity consumption and power generation.

• 한국태양에너지학회 논문집
• /
• 제31권5호
• /
• pp.99-104
• /
• 2011

It has to take quantitative energy usage of high school education facilities in nations to set goals of their energy reduction. Therefore, The purpose of this study is to present various analysis result of energy consumption that is a statistic alanalysis of high school education facilities in Korea to set the goal of energy saving. This study has enforced analysis and has provided used energy for the year 2008 and general information from 2022 high school education facilities in 16 cities in South Korea by the relevant agency. Used energy sources in high school education facilities are electricity, gas for heating, oil, coal, water, and this study has changed the various used energy sources as unit 'kWh' only for comparison and analysis them.

• Journal of Electrical Engineering and Technology
• /
• 제7권6호
• /
• pp.852-858
• /
• 2012

This paper describes evaluation results of the wind power penetration limit (WPPL) and the wind energy penetration (WEP) in the Mongolian central power system (MCPS). A wind power plant (WPP) in a power system possesses an output power limit because the power system must maintain a balance between the generation and consumption of electricity at all times in order to achieve an adequate level of quality. The instantaneous penetration limit (IPL) of wind generation at a load is determined as the minimum of the three technical constraints: the minimum output, the ramp rate capability, and the spinning reserve of the conventional generating units. In this paper, a WPPL is defined as the maximum IPL divided by the peak load. A maximal variation rate (VR) of wind power is a major factor in determining the IPL, WPPL, and WEP. This paper analyzes the effects of the maximal VR of wind power on the WPPL, WEP, and capacity factor (CF) in the MCPS. The results indicate that a small VR can facilitate a large amount of wind energy while maintaining a high CF with increased wind power penetration.