• Journal of Digital Convergence
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• v.11 no.4
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• pp.279-284
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• 2013

Improve the global environment for low carbon emissions and green energy, and the growing interest in IT technology, combined with the existing power grid to achieve this, to achieve more efficient and environment-friendly smart grid smart grid projects around the world actively being deployed. A smart grid is expected to be a modernization of the legacy electricity network. Therefore, this research provides a secure smart grid model so that it provides better monitoring, protecting and optimizing automatically to operation of the interconnected elements.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4145-4164
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• 2016

Energy harvesting is an increasingly attractive source of power for cellular networks, and can be a promising solution for green networks. In this paper, we consider a cellular network with power beacons powering multiple mobile terminals with microwave power transfer in energy beamforming. In this network, the power beacons are powered by grid and renewable energy jointly. We adopt a dual-level control architecture, in which controllers collect information for a core controller, and the core controller has a real-time global view of the network. By implementing the water filling optimized power allocation strategy, the core controller optimizes the energy allocation among mobile terminals within the same cluster. In the proposed green energy cooperation paradigm, power beacons dynamically share their renewable energy by locally injecting/drawing renewable energy into/from other power beacons via the core controller. Then, we propose a new water filling optimized green energy cooperation management strategy, which jointly exploits water filling optimized power allocation strategy and green energy cooperation in cellular networks. Finally, we validate our works by simulations and show that the proposed water filling optimized green energy cooperation management strategy can achieve about 10% gains of MT's average rate and about 20% reduction of on-grid energy consumption.

• Bulletin of the Korea Photovoltaic Society
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• v.6 no.1
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• pp.86-91
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• 2020

Nepal is among the richest in terms of water resource availability and it is one of the most important natural resources of the country. Currently, 72% of the population is electrified through the national grid system. The power generation mix into the grid is hydro dominated with minor shares generated from solar and thermal (accounts for less than 1%). To achieve sustainable development in the power sector it is essential to diversify power generation mix into the grid. Knowing the facts, the government has a plan to achieve a 5-10% share of power generation from solar and mix it into the grid system. Solar is the second most abundant, prominent and free source of renewable in the context of Nepal. This study mainly focuses on the grid-connected solar system, its importance, present status, government efforts, and its need. It is based on the review of literature, news published in national newspaper online news and international organization's report.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.784-793
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• 2022

Grid-connected distributed power generation has been widely used in green energy generation. However, due to the distributed characteristics, distributed power generation is difficult to be dynamically allocated and monitored in the electrical control process. In order to solve this problem, this research combined the Internet of Things (IoT) with the automatic control system of electrical engineering to improve the control strategy of the power grid inverter according to the characteristics of the IoT system. In the research, a connection system of the power grid inverter and the IoT controller were designed, and the application effect was tested by simulation experiments. The results showed that the power grid inverter had strong tracking control ability for current and power control. Meanwhile, the electrical control system of the IoT could independently and dynamically control the three-phase current and power. The given value was reached within 50 ms after the step signal was input, which could protect the power grid from being affected by the current. The overall system could realize effective control, dynamic control and protective control.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2496-2512
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• 2021

The requirements for powerful computing capability, high capacity, low latency and low energy consumption of emerging services, pose severe challenges to the fifth-generation (5G) network. As a promising paradigm, mobile edge networks can provide services in proximity to users by deploying computing components and cache at the edge, which can effectively decrease service delay. However, the coexistence of heterogeneous services and the sharing of limited resources lead to the competition between various services for multiple resources. This paper considers two typical heterogeneous services: computing services and content delivery services, in order to properly configure resources, it is crucial to develop an effective offloading and caching strategies. Considering the high energy consumption of 5G base stations, this paper considers the hybrid energy supply model of traditional power grid and green energy. Therefore, it is necessary to design a reasonable association mechanism which can allocate more service load to base stations rich in green energy to improve the utilization of green energy. This paper formed the joint optimization problem of computing offloading, caching and resource allocation for heterogeneous services with the objective of minimizing the on-grid power consumption under the constraints of limited resources and QoS guarantee. Since the joint optimization problem is a mixed integer nonlinear programming problem that is impossible to solve, this paper uses deep reinforcement learning method to learn the optimal strategy through a lot of training. Extensive simulation experiments show that compared with other schemes, the proposed scheme can allocate resources to heterogeneous service according to the green energy distribution which can effectively reduce the traditional energy consumption.

• The Journal of Information Systems
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• v.22 no.1
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• pp.225-248
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• 2013

Korean government has been implementing a smart grid testbed in Jeju Island for the low-carbon green growth. As smart grids are in the early stage of their diffusion, strategic guidelines and related measures are needed to spread them successfully. In general, the successful diffusion of new technologies or new products are mostly determined in its early stages. With the introduction of smart grids, the electricity market paradigm will be transformed into user-oriented from provider-oriented. Thus, a study on the diffusion of smart grids from the perspective of users is necessary. This paper examines factors affecting the adoption and diffusion of smart grids from users' perspectives and provide strategic guidelines for diffusing the smart grid. Researchers conducted in-depth interviews with 41 people who have been already using smart grids in the Jeju testbed. Semi-structured interviews were used to collect data. The interviews were recorded on a digital voice recorder memory and subsequently transcribed verbatim. A total of 133 pages of transcripts were obtained from about 10 hours interviews. 97 concepts, 47 sub-categories and 19 categories were identified through open coding of grounded theory. We suggested a paradigm model for diffusing smart grids and total of seven propositions as strategic guidelines.

• KIEAE Journal
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• v.15 no.6
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• pp.5-10
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• 2015

Purpose: To evaluate the economic performance of grid-connected photovoltaic system in residential house, household electricity bill policy of Korea Electric Power Corporation (KEPCO) must be applied precisely, and market tendency and uncertainty of system also need to be considered. In this study, to evaluate the economic feasibility of PV system, we measured PV power generation and electricity consumption of six of Green home in Daejeon through web based remote monitoring system. Method: We applied Monte-Carlo simulation based on life cycle cost analysis, to reflect an uncertainty of main factor in economic feasibility evaluation of photovoltaic system. Result: First, with deterministic analysis, the difference of NPV of cumulative financial savings among households varied from -3,310 ~ 24,170 thousand won, portraying notably big range. Also the possibility of getting the same result was 50% when applying uncertainty. Second, the higher electricity consumption is, the more economic feasibility of photovoltaic system increases because KEPCO uses progressive taxation in household electricity bill policy. Third, The contribution to variance of electricity price increases in NPV varied from 98.5% to 99.9%. While the inflation rate and annual degradation contributed very little to none.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.12
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• pp.1192-1196
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• 2009

Recently, the environment contamination problem and energy saving are the social issues. So, the Green IT based Smart Grid was suggested. The smart grid will let rates fluctuate even more dynamically, depending on conditions using energy. Thus, green IT includes the dimensions of environmental sustainability and the economics of energy efficiency. The smart controller in which it is controlled by DR in order to manage the energy consumption by using AMI is needed in order to apply its technology to the real life. In this paper, DR_WTIM of the IEEE1451.5 base which has the DR function for connecting to AMI of the wireless base is developed. By using this apparatus for the power control system, the energy saving effect is shown. Moreover, by using the IEEE1451.5 technology, the problem of energy consumption is solved in order to apply to power controller designed for efficient use energy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4724-4747
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• 2016

To efficiently reduce on-grid energy consumption, the admission control algorithm in the hybrid energy powered cellular network (HybE-Net) with base stations (BSs) powered by on-grid energy and solar energy is studied. In HybE-Net, the fluctuation of solar energy harvesting and energy consumption may result in the imbalance of solar energy utilization among BSs, i.e., some BSs may be surplus in solar energy, while others may maintain operation with on-grid energy supply. Obviously, it makes solar energy not completely useable, and on-grid energy cannot be reduced at capacity. Thus, how to control user admission to improve solar energy utilization and to reduce on-grid energy consumption is a great challenge. Motivated by this, we first model the energy flow behavior by using stochastic queue model, and dynamic energy characteristics are analyzed mathematically. Then, fuzzy logic based admission control algorithm is proposed, which comprehensively considers admission judgment parameters, e.g., transmission rate, bandwidth, energy state of BSs. Moreover, the index of solar energy utilization balancing is proposed to improve the balance of energy utilization among different BSs in the proposed algorithm. Finally, simulation results demonstrate that the proposed algorithm performs excellently in improving solar energy utilization and reducing on-grid energy consumption of the HybE-Net.

• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.284-291
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• 2018

As environmental pollution has become worse green technologies to replace or reduce consumption of fossil fuel get spotlight from government, industry and academia globally. It is reported that 40% of carbon dioxide emission is caused by electricity power generation. And 37% of end user electricity power is used by residential costumer in US. Smart Grid is considered as one of promising technology to alleviate severe environmental problem. In residential environment, Home Energy Management System (HEMS) can play a key role for green smart home. The HEMS can give several benefits like aslowering electric utility bill, improvement of efficiency of electric power consumption and integration of generator using renewable energy resources. However just limited functions of HEMS can be used for residential customer in real life because of lack of smart function in home appliances and optimal managing software for HEMS. This study provides comprehensive analysis for Home Energy Management System for residential customer. Simple HEMS system with real products on the market are explained and limitation of current HEMS are also discussed.