• IE interfaces
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• v.16 no.1
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• pp.16-26
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• 2003

In Korea, cooling power load, which occupies about 20% of peak load in 2000 and fluctuates depending on the popular usage of air conditioning systems, has been recently the focus of the load management. The first work of KEPCO (Korea Electric Power Corporation) to regulate cooling load as low as possible was to estimate its approximate scale and to develop the indirect methods to estimate it from the available time series data for the average hourly loads. However, KEPCO would like to have their methods improved both theoretically and practically. In this paper, we analyze their current indirect methods and detect their faults to design better indirect estimation methods. Under one of the assumptions of "no cooling load in April or May", the linear relationship between basic loads and GDP's, and the normalized seasonal factors of the Winters' multiplicative seasonal model, we provide ten indirect estimation methods in total and suggest the estimated cooling load(1988-1999) based on our various indirect methods.

• IE interfaces
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• v.11 no.1
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• pp.207-214
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• 1998

Since the natural gas air-conditioning not only increases the base load of the gas company but also decreases the summer peak load of the electricity company, it is considerded as an efficient demand-side management program. This paper suggests the economic evaluation method of the gas air-conditioning program from the perspectives of the participants, the pipeline gas company, the local distribution company, the electricity company, and the total resources. The absorption type gas air-conditioning/space-heating is selected as a case study to illustrate the economic analysis of the natural gas air-conditioning.

• Electronics and Telecommunications Trends
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• v.33 no.5
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• pp.42-50
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• 2018

UDN is expected to be a type of network capable of satisfying the requirements various 5G services, such as the peak data rate, connection density, and area traffic capacity. Technical challenges for 5G UDN, such as interference management, resource management, mobility management, load balancing, and energy efficiency are discussed. In addition, candidate technologies for solving these challenges, and their related standardization trends, are summarized in this article.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.3
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• pp.119-124
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• 2011

Electric night storage heater was introduced and disseminated for power grid balancing and efficient management of power generation facility. But fuel cost for heating has been increased rapidly while the cost of electricity increased slightly. This abnormal rate system caused peak load in winter at last. To solve this problem, application of an air source heat pump was suggested. In the study, the effect of replacing night heater by heat pump and the economics were analysed. In addition the expectation of prospect of heat pump penetration was simulated based on surveyed and investigated data. As a result, fund supporting as well as institutional backing was needed for effective propagation and return of investment.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.155-156
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• 2015

Recently, electricity consumption has rapidly increased along with economic growth. The operating strategy using emergency generator is aimed, to resolve a demand response management. For strategy of peak shedding using emergency generator, it is essential to introduce the fast transfer switching device. One of the most effective solutions is to use a static transfer switch (STS) based on thyristor. However, the characteristic of natural commutated SCR thyristor should anticipate short duration voltage sag. STS system thus requires more than a quarter cycle to successfully complete transfer process. This paper proposes the operation scheme of the STS system using the forced-commutation technique to mitigate instantaneous voltage sag during peak transfer process. Proposed STS system improved turn-off characteristic thus accomplishes the peak load shedding satisfied power quality. Performance of the proposed STS system is evaluated using electromagnetic transient program (EMTP) to confirm the effectiveness.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.64-74
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• 2015

Because of the burgeoning demand of the energy, the countries are finding sustainable solutions for these emerging challenges. Demand Side Management is playing a significant role in managing the demand with an aim to support the electrical grid during the peak hours. However, advancement in controls and communication technologies, the aggregators are appearing as a third party entity in implementing demand response program. In this paper, a detailed mathematical framework is discussed in which the aggregator acts as an energy service provider between the utility and the consumers, and facilitate the consumers to actively participate in demand side management by introducing the new concept of demand reduction bidding (DRB) under constrained direct load control. Paper also presented an algorithm for the proposed framework and demonstrated the efficacy of the algorithm by considering few case studies and concluded with simulation results and discussions.

• Journal of information and communication convergence engineering
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• v.14 no.2
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• pp.122-128
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• 2016

In the future, hybrid power management systems using fuel cells (FCs) and batteries will be used as the driving power systems of ships. These systems consist of an FC, a converter, an inverter, and a battery. In general, an FC provides steady-state energy; a battery provides the dynamic energy in the start state of a ship for enabling a smooth operation, and provides or absorbs the peak or dynamic power when the load varies and the FC cannot respond immediately. The FC voltage range is very wide and depends on the load; Therefore, the FC cannot directly connect to the inverter. In this paper, we propose a power management strategy and design process involving a unidirectional converter, a bidirectional converter, and an inverter, considering the ship's operating conditions and the power conditions of the FC and the battery. The presented experimental results were verified through a simulation.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.207-217
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• 2018

Recently, the importance of energy demand management, particularly peak load control, has been increasing due to the policy changes of the Second Energy Basic Plan. Even though the installation of distributed generation systems such as Photovoltaic and energy storage systems (ESS) are encouraged, high initial installation costs make it difficult to expand their supply. In this study, the power consumption of a university building was measured in real time and the measured power consumption data was used to calculate the optimal installation capacity of the Photovoltaic and ESS, respectively. In order to calculate the optimal capacity, it is necessary to analyze the operation methods of the Photovoltaic and ESS while considering the KEPCO electricity billing system, power consumption patterns of the building, installation costs of the Photovoltaic and ESS, estimated savings on electric charges, and life time. In this study, the power consumption of the university building with a daily power consumption of approximately 200kWh and a peak power of approximately 20kW was measured per minute. An economic analysis conducted using these measured data showed that the optimal capacity was approximately 30kW for Photovoltaic and approximately 7kWh for ESS.

• Smart Media Journal
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• v.7 no.2
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• pp.71-77
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• 2018

This paper proposes the components of the energy management system (EMS) for optimum operation of renewable energy and associated energy storage system (ESS), the functions to be considered in designing, the analysis of operational effects, and finally the reduction of electricity costs. To accomplish the objectives, a lithium-ion battery system and an energy management system have installed in a PV system, and it presents the results analyzed with operation data for a year. To increase the system operation efficiency, we propose the effect that EMS is used to replace the demand power at the peak time with the charge power at the light load time, which suggests the influence of contributing to the charge benefit and load leveling according to the ESS tariff.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.58-68
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• 2009

Low impact development (LID) technique is relatively new concept to reduce surface runoff and pollutant loading from land cover by attempting to match predevelopment condition with various integrated management practices (IMPs). In this study, computational model for designing and evaluating LID, named LIDMOD, was developed based on SCS-CN method and applied at Andong bus terminal to evaluate LID applicapability and design retention/detention area for volume or peak flow control. LIDMOD simulated with 21 years simulation period that yearly surface runoff by post-development without LID was significantly higher than that with LID showing about 2.8 times and LID could reduce efficiently yearly surface runoff with 75% reduction of increased runoff by conventional post development. LIDMOD designed detention area for volume/peak flow control with 20.2% of total area by hybrid design. LID can also efficiently reduce pollutant load from land cover. Pollutant loads from post-development without LID was much higher than those from pre-development with showing 37 times for BOD, 2 times for TN, and 9 times for TP. Pollutant loads from post-development with LID represented about 57% of those without LID. Increasing groundwater recharge reducing cooling and heating fee, creating green refuge at building area can be considered as additional benefits of LID. At the point of reducing runoff and pollutant load, LID might be important technique for Korean TMDL and LIDMOD can be useful tool to calculate unit load for the case of LID application.