• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.64 no.4
• /
• pp.246-250
• /
• 2015

Solar energy will be an increasingly important part of power generation because of its ubiquity abundance, and sustainability. To manage effectively solar energy to power system, it is essential part In this paper, we develop the PV power prediction algorithm using adaptive neuro-fuzzy model considering various input factors such as temperature, solar irradiance, sunshine hours, and cloudiness. To evaluate performance of the proposed model according to input factors, we performed various experiments by using real data.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.1324-1332
• /
• 2008

The change of the transportation circumstance related to the deep environmental pollution, escalation of the energy price, increasing social cost of the congestion and traffic accident, improving a income level, advanced social structure etc, is rapidly proceeded. For the corresponding this transportation circumstance, the role of the railway is being increased and that is friendly with environment, efficient for the energy, observed the time schedule and the transportation device which is high speed and safe mass transportation. In addition, government's R&D investment is being increased according to deeping a strength of the international competitiveness through the technical innovation. So railway's R&D investment is being increased. Accordingly, This study suggest improving a fruit of the R&D related to railway R&D system for a efficient R&D investment.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.67 no.1
• /
• pp.37-41
• /
• 2018

In this paper, the ESS(Energy Storage System) is interconnected in order to reduce the maximum load in the distribution system and the target location of the ESS is set to be close to the rated voltage. We also applied the weights to nodes with large capacity and number of customers in the system. In the future, the interconnected location of the ESS was determined until 2029 in consideration of the load increase rated of the system. We propose a cooperative decision algorithm of interconnected location of ESS for Power Distribution System.

• Journal of Korean Society on Water Environment
• /
• v.36 no.6
• /
• pp.535-545
• /
• 2020

This study aims to conserve and monitor energy use in public sewage treatment plants by utilizing data from the SCADA system and by controlling the aeration rate required for maintaining effluent water quality. Power consumption in the sewage treatment process was predicted using the equipment's uptime, efficiency, and inherent power consumption. The predicted energy consumption was calibrated by measured data. Additionally, energy efficiency indicators were proposed based on statistical data for energy use, capacity, and effluent quality. In one case study, a sewage treatment plant operated via the SBR process used ~30% of energy consumed in maintaining the bioreactors and treated water tanks (included decanting pump and cleaning systems). Energy consumption analysis with the K-ECO Tool-kit was conducted for unit processing. The results showed that about 58.7% of total energy consumed was used in the preliminary and biological treatment rotating equipment such as the blower and pump. In addition, the energy consumption rate was higher to the order of 19.2% in the phosphorus removal process, 16.0% during sludge treatment, and 6.1% during disinfection and discharge. In terms of equipment energy usage, feeding and decanting pumps accounted for 40% of total energy consumed following 27% for blowers. By controlling the aeration rate based on the proposed feedback control system, the DO concentration was reduced by 56% compared pre-controls and the aeration amount decreased by 28%. The overall power consumption of the plant was reduced by 6% via aeration control.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.67 no.3
• /
• pp.143-148
• /
• 2018

In this paper, the optimal fuzzy logic controller(FLC) for a hybrid renewable energy system(HRES) is proposed. Generally, hybrid renewable energy systems can consist of wind power, solar power, fuel cells and storage devices. The proposed FLC can effectively control the entire HRES by determining the output power of the fuel cell or the absorption power of the electrolyzer. In general, fuzzy logic controllers can be optimized by classical optimization algorithms such as genetic algorithms(GA) or particle swarm optimization(PSO). However, these FLC have a disadvantage in that their performance varies greatly depending on the control parameters of the optimization algorithms. Therefore, we propose a method to optimize the fuzzy logic controller using the teaching-learning based optimization(TLBO) algorithm which does not have the control parameters of the algorithm. The TLBO algorithm is an optimization algorithm that mimics the knowledge transfer mechanism in a class. To verify the performance of the proposed algorithm, we modeled the hybrid system using Matlab Tool and compare and analyze the performance with other classical optimization algorithms. The simulation results show that the proposed method shows better performance than the other methods.

• Transactions of the Korean hydrogen and new energy society
• /
• v.9 no.1
• /
• pp.38-45
• /
• 1998

An energy crisis is expected in near future. Fossil fuel such as oil and natural gas has been used and will be no longer supplied enough to demand in the beginning of coming century. The use of the fuel makes a lot of environmental pollution to threaten human being's health especially in big cities and produces a lot of $CO_2$ to make green house effect of the earth. It is the time to use clean fuel such as hydrogen to prevent the expected energy crisis and the pollution. A new engine such as fuel cell can be used instead of the conventional internal combustion engine with 2 to 3 times higher efficiency of the conventional engine. The fuel cell uses hydrogen and oxygen and produces electric energy and pure water, which is a calm engine without air pollution. In big cities the city buses and the taxies powered by hydrogen fuel cells are suggested to be operated for clean environment. A model of the total energy system for production, transportation and utilization of hydrogen is calculated.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.6
• /
• pp.2442-2447
• /
• 2015

Because an electric railway vehicle is a large scale moving load, it can cause various kinds of power quality problems in the railroad power system. The power quality impacts are considered as the strong instantaneous stresses to the related power systems and can cause an accelerating aging and a malfunction of the power supplying components. Therefore, it is necessary to detect the small and intermittent symptoms mixed in the voltage waveform. However, they cannot be detected by the triggering functions of the existing power analyzers installed in the railway systems. This paper will examine the drawback of some fast detection tools and propose an advanced detecting and analyzing method based on a combined TEO and STFT algorithm.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.20 no.5
• /
• pp.471-478
• /
• 2015

The new islanding detection method using wavelet energy is proposed in this paper. The proposed method is based on the autocorrelation of the wavelet energies, which is obtained from the high-frequency components of the grid voltage. It has the enhanced detection capabilities in the UV/OV/UF/OF region, which the conventional passive methods cannot obtain. The mathematical theories on the wavelet are presented, and the performance effectiveness is proved by the experimental results.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.2
• /
• pp.79-88
• /
• 2022

Recently, securing stable supply of fresh food is deemed as one of the important tasks. Accordingly, now the presence of cold chain along with the needs of a comfortable and healthy life is growing as the online market expands and the contactless industry grows, however, cold chain is being studied only in the aspect of ground and sea transportation. And, due to global warming and strengthening global environmental regulations, we believe that it is necessary to convert the existing road-centered logistics system into a railway-centered logistics system, a low-carbon transportation means. Therefore, in this paper we calculated the maximum energy required by the reefer container as a basic research necessary for constructing the low temperature distribution and cold chain based on the reefer container railway, and conducted a study on methods of supplying the reefer container power utilizing 1. tramline, 2. battery, 3. generator. The results of this paper can be utilized as a foundational study for building a cold chain based on a reefer container dedicated to freight trains in the future.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.66 no.3
• /
• pp.144-149
• /
• 2017

There is a little research on DC arc detection when compared to a large number of literature and patents on AC arc detection. However, as DC energy sources such as photovoltaic power generation facilities and fuel cells are introduced, research on DC arc has become as important as AC arc detection in terms of circuit protection and system reliability enhancement. In this paper, we have developed an arc detection method for photovoltaic system using frequency analysis. Through various experiments, it was confirmed that the proposed method effectively detects the arc.