• 한국산학기술학회논문지
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• 제16권1호
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• pp.860-867
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• 2015

본 논문은 PSO 알고리즘을 이용하여 물 재이용 펌프 시스템의 에너지비용을 최소화 할 수 있는 방법을 제안한다. 1시간 단위의 시간대에서 펌프제어를 위해 계시별 요금제를 기반으로 하여 최적화 구간을 설정하고 PSO알고리즘을 이용하여 에너지 비용을 절감할 수 있도록 펌프동작을 제어한다. 물 재이용 펌프시스템에서 고정된 유량을 출력하는 펌프와 입력전력을 가변할 수 있는 펌프에 대해 TOU 기반에서 에너지 비용을 최대로 줄일 수 있도록 시스템을 동작시킨다. 시뮬레이션을 통해 제안한 에너지 비용 절감 방법이 기존 수위기반의 제어방법보다 비용을 절감할 수 있음을 확인할 수 있다.

• 전기학회논문지
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• 제56권1호
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• pp.18-27
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• 2007

Successful operation of power system under regulated as well as deregulated electricity markets is very important. This paper presents marginal power flow evaluation of KEPCO system in view point of physical and operation mode by using Physical and Operational Margins (POM Ver.2.2), which is developed by V&R Energy System Research. This paper introduces feature and operation mode of POM Ver.2.2 and then evaluates scenarios of 6 lines contingencies of 765kv of KEPCO system at peak load time on summer in 2006 you. The case study for actual 2006 year KEPCO system shows that this POM program is applicable sufficiently to KEPCO system. Futhermore, it demonstrates that it is helpful for operator's operating the system successfully by evaluating physical and operational margins quickly for various contingencies occurred in KEPCO system. Eventually, it will assist operators to operate more reliably the KEPCO system in future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.878-882
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• 1996

This paper discusses the definition and concepts, approach methodologies, capable application areas in electricity business, and tentative calculation of avoided generation costs based on the Korea's official long-term generation expansion plan. The objective to evaluate avoided costs of a resource is to supply decision makers with the breakeven cost of a targeting avoided resource. For the evaluation of avoided costs of the Korea's generation system, we consider the pseudo-DSM option which has 1,000MW peak savings, load factor with 70 percent, and life-time With 25 years as the avoided resource. The DSM resource can save the fuel and capacity additions of a electric utility during its life time. The capacity and fuel savings are evaluated from the two different cashflows with and Without the DSM option, which are generated on the basis of the generation system optimization model(WASP-II), independently. The breakeven kWh costs of the DSM option over this 25-year period is projected to be 34.1[won/kWh], which is composed of generation-capacity and fuel avoided costs with 101.139[won/kW] and 17.6[won/kWh], respectively.

• Advances in Energy Research
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• 제7권2호
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• pp.85-100
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• 2020

Distributed energy resources (DERs) are essential for coping with growing multiple energy demands. A microgrid (MG) is a small-scale version of the power system which makes possible the integration of DERs as well as achieving maximum demand-side management utilization. Hence, this study focuses on the analysis of optimal power dispatch considering economic aspects in a multi-carrier microgrid (MCMG) with price-responsive loads. This paper proposes a novel time-based demand-side management in order to reshape the load curve, as well as preventing the excessive use of energy in peak hours. In conventional studies, energy consumption is optimized from the perspective of each infrastructure user without considering the interactions. Here, the interaction of energy system infrastructures is considered in the presence of energy storage systems (ESSs), small-scale energy resources (SSERs), and responsive loads. Simulations are performed using GAMS (General Algebraic modeling system) to model MCMG, which are connected to the electricity, natural gas, and district heat networks for supplying multiple energy demands. Results show that the simultaneous operation of various energy carriers, as well as utilization of price-responsive loads, lead to better MCMG performance and decrease operating costs for smart distribution grids. This model is examined on a typical MCMG, and the effectiveness of the proposed model is proven.

• 한국산업융합학회 논문집
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• 제23권6_1호
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• pp.907-915
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• 2020

Specification selection, Layout, specifications and combinations of Power Drives, and Ship motions were studied for FGPP(Floating Gas-fired Power Plants), which are still needed in areas such as the Caribbean, Latin America, and Southeast Asia where electricity is not sufficiently supplied. From this study, the optimal equipment layout in ships was derived. In addition, the difference between engine and turbine was verified through LCOE(Levelized Cost of Energy) comparison according to the type and combination of Power Drives. Analysis of Hs(Significant Height of wave) and Tp(spectrum Peak Period of wave) for places where this FGPP will be tested or applied enables design according to wave characteristics in Brazil and Indonesia. Normalized Sloshing Pressures of FGPP and LNG Carrier are verified using a sloshing analysis program, which is CFD(Computational Fluid Dynamics) software developed by ABS(American Bureau of Shipping). Power Transmission System is studied with Double bus with one Circuit Breaker Topology. A nd the CFD analysis allowed us to calculate linear roll damping coefficients for more accurate full load conditions and ballast conditions. Through RAO(Response Amplitude Operator) analysis, we secured data that could minimize the movement of ships according to the direction of waves and ship placement by identifying the characteristics of large movements in the beam sea conditions. The FGPP has been granted an AIP(Approval in Principle) from a classification society, the ABS.

• 조명전기설비학회논문지
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• 제22권9호
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• pp.55-61
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• 2008

최근 전력수요의 높은 증가율로 인하여 전력계통에 가장 안정적으로 전력을 공급하기 위한 적정예비력을 얼마만큼을 가져야 할 것인가? 하는 필요성이 강조되고 있다. 본 연구에서는 연도별 계통규모와 예비력 및 예비율의 변화 풍향 분석을 통하여 계통규모가 증가할수록 적정 예비력은 증가하고 있는 반면에 예비율은 하락하는 추세를 보이고 있는 것을 분석하였다. 이 자료를 관계로 현재시점에서 단기 전력수급전망에 적용되는 공급예비력으로 산정한 600만[kW]는 적정수준이라 여겨진다. 또한 최대전력수요가 5,000만[kW]를 넘어서면서 적정수준인 $10{\sim}12[%]$ 예비율 보다는 적정수준의 예비력을 산정하여 적용하는 것이 전력계통을 경제적이고 안정적으로 운영할 수 있다고 분석되었다.

• 한국지열·수열에너지학회논문집
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• 제10권2호
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• pp.19-23
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• 2014

In the capital of Mongolia where the air quality is getting worse due to the coal consumption used for electricity generation and district heating, the application of geothermal systems in the housing sector is recently designed for high class resort. In this study, the case of applying a geothermal system in a house in Mongolia is examined. The effects of passive house design on the needed heat pump capacity, as well as the annual energy consumption are analyzed. Moreover, as the initial costs, except labor fee, are assumed similar to Korea, cost analysis for several cases is examined, too. From the results, if a house is designed according to passive house standard instead of ASHRAE standard, the heat pump capacity can be expected to be reduced from 16 to 5~6 RT. Furthermore, although the initial cost of architectural cost might increased by 29 M\, the total initial cost is reduced by 14 M\, while the annual energy consumption is reduced by 14%. This is mainly driven by the fact that the geothermal system which serves as the main system to cover the building needs, with a high initial cost for fulfilling the peak requirements.

• 전기학회논문지
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• 제63권5호
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• pp.713-718
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• 2014

DC urban railway power system consists of DC power network and AC power network. The DC power network supplies electric power to railway vehicles and the AC power network supplies electric power to station electric equipment. Recently, because of power consumption reduction and peak load shaving, intelligent measurement of regenerative energy and renewable energy adapted on DC urban railway is required. For this reason, DC smart metering system for DC power network shall be developed. Therefore, in this paper, DC voltage sensor, current sensor, and DC smart meter were developed and evaluated by performance test. DC voltage sensor was developed for measuring standard voltage range of DC urban railway, and DC current sensor was developed as hall effect split core type in order to install in existing system. DC smart meter possesses function of general intelligent electric power meter, such as measuring electricity and wireless communication etc. And, DC voltage sensor showed average 0.17% of measuring error for 2,000V/50mA, and current sensor showed average 0.21% of measuring error for ${\pm}2,000V/{\pm}4V$ in performance test. Also DC smart meter showed maximum 0.92% of measuring error for output of voltage sensor and current sensor. In similar environment for real DC power network, measuring error rate was under 0.5%. In conclusion, accuracy of DC smart metering system was confirmed by performance test, and more detailed performance will be verified by further real operation DC urban railway line test.

• 한국HCI학회논문지
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• 제12권4호
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• pp.65-73
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• 2017

전력 수요가 증가하고 재생 가능 에너지에 대한 관심이 증폭됨에 따라, 수요를 억제하여 필요한 공급량을 줄일 수 있는 '수요반응' 프로그램에 대한 관심이 증가하고 있다. 본 연구는 가정에 스마트미터를 구비한 국내 사용자들을 대상으로 진행된 에너지 수요반응 실증사업에 대한 실증분석으로, 사전심층 인터뷰, 설문 및 기술수용모델 분석을 통하여 가정 전력 사용자들이 수요반응 프로그램을 받아들이는 데 중요한 요인들을 살펴본다. 수요반응의 목표는 피크시간대에 미션이 발령되면 전력사용량을 평소보다 줄이는 것이며, 실험대상은 스마트미터 구입 경로와 에너지를 절감했을 때 보상받는 방식에 따라 2개의 상이한 집단으로 구성되었다. 집단 A는 주로 IoT플랫폼 서비스에 가입하는 과정에서 마케터와의 대화를 통해 전체 서비스 중 하나인 스마트미터 서비스에 함께 가입하는 경로로 수요반응 프로그램에 유입되었고, 보상으로는 통신비 할인을 받았다. 반면 집단 B는 스마트미터를 자발적으로 구매하거나 에너지 자립 마을 지역주민으로서 지자체 지원을 통해 스마트미터를 지원 받아 프로그램에 유입되었고, 미션 성공에 대한 보상은 사회적 기부를 통해 이루어졌다. 분석 결과 집단 A는 인지된 용이성과 인지된 유용성 외에 인지된 유희성도 포함된 확장된 기술수용모델이 적합함을 알 수 있었고,집단 B는 모델의 적합도가 떨어지기는 하지만 집단 A에 비해 인지된 유용성에 대한 중요도가 높음을 확인할 수 있었다. 이와 같은 결과는 집단 특성에 따른 프로그램 설계방향을 제시하여 향후 수요반응 프로그램을 효과적으로 운영하는 데에 도움을 줄 것으로 보인다.

• International Journal of Computer Science & Network Security
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• 제21권11호
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• pp.345-353
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• 2021

Cloud computing represent a new era of computing that's forms through the combination of service-oriented architecture (SOA), Internet and grid computing with virtualization technology. Virtualization is a concept through which every cloud is enable to provide on-demand services to the users. Most IT service provider adopt cloud based services for their users to meet the high demand of computation, as it is most flexible, reliable and scalable technology. Energy based performance tradeoff become the main challenge in cloud computing, as its acceptance and popularity increases day by day. Cloud data centers required a huge amount of power supply to the virtualization of servers for maintain on- demand high computing. High power demand increase the energy cost of service providers as well as it also harm the environment through the emission of CO₂. An optimization of cloud computing based on energy-performance tradeoff is required to obtain the balance between energy saving and QoS (quality of services) policies of cloud. A study about power usage of resources in cloud data centers based on workload assign to them, says that an idle server consume near about 50% of its peak utilization power [1]. Therefore, more number of underutilized servers in any cloud data center is responsible to reduce the energy performance tradeoff. To handle this issue, a lots of research proposed as energy efficient algorithms for minimize the consumption of energy and also maintain the SLA (service level agreement) at a satisfactory level. VM (virtual machine) consolidation is one such technique that ensured about the balance of energy based SLA. In the scope of this paper, we explore reinforcement with fuzzy logic (RFL) for VM consolidation to achieve energy based SLA. In this proposed RFL based active VM consolidation, the primary objective is to manage physical server (PS) nodes in order to avoid over-utilized and under-utilized, and to optimize the placement of VMs. A dynamic threshold (based on RFL) is proposed for over-utilized PS detection. For over-utilized PS, a VM selection policy based on fuzzy logic is proposed, which selects VM for migration to maintain the balance of SLA. Additionally, it incorporate VM placement policy through categorization of non-overutilized servers as- balanced, under-utilized and critical. CloudSim toolkit is used to simulate the proposed work on real-world work load traces of CoMon Project define by PlanetLab. Simulation results shows that the proposed policies is most energy efficient compared to others in terms of reduction in both electricity usage and SLA violation.