• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.279-286
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• 2021

Recently, the effort of enterprises are visualized to correspond for 4th industrial revolution and climate change. Reaching the operation of industrial facilities are one of these efforts and is actively progressing under identical condition between real and virtual world through introduction of cyber-physical system (CPS). However, the problem on no unified definition for CPS still exists. Thus, in this paper, we review the previous concept of CPS. We propose new concept of CPS with four sections such as real world section, communication section, virtual world section and management section. We also propose definite concept by classifying the layer of each section. In order to confirm the possibility of application for proposed concept of CPS, we applied simple motor. We compare the result for torque between real motor and virtual motor. Finally we confirm that the applicability of proposed concept of CPS is very high.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.123-128
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• 2021

As the spread of DC power distribution systems increases, the occurrence of failures and fire accidents are also increasing. In particular, the ESS fire accident, which is a component of the smart grid, and the fire accident of the solar power system, which is a direct current system, are caused by problems in the electrical connection between system components as the supply of new and renewable energy rapidly increases and old facilities increase. An arc that can cause a direct fire by releasing the induced light and heat has been pointed out as one of the causes of fire. Therefore, the problem of such an arc defect is that it is impossible to block an arc accident in advance with the existing overcurrent circuit breaker and earth leakage circuit breaker. In this paper, we intend to develop a test equipment that satisfies international standardization and to develop a DC arc generator to protect against failure and fire caused by arcing.

• Journal of IKEEE
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• v.23 no.2
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• pp.495-501
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• 2019

This paper proposes a variable passive harmonic filter for reduction and improvement of harmonics and power factor of single-phase uninterruptible power supply(UPS) with full bridge rectifier. Recently, UPSs have excellent harmonic and power factor operation characteristics by applying 2-level or more levels of power conversion methods. On the other hand, the single-phase UPS of the full bridge rectifier seriously causes the third, fifth, and seventh harmonics, and the power factor reduction on the grid side. Therefore, we present a variable passive harmonic filter for eliminating (2n+1) order harmonics and improving the power factor generated by the full bridge rectifier operation. In order to evaluate the performance of the proposed variable harmonic filter, the its validity is verified by various simulations and experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.307-309
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• 2016

This paper present about the system for sensing and controlling a wireless power transfer system using bluetooth protocol in robot, healthcare, smart-grid, and autonomous car. Recently a variety of applications using the Internet of Things (Internet of Things) and machine to machine (Machine to Machine) have been raised in many industries. To do this, it requires the fusion technology which is constituted with control, computing and networking. Embedded system is centered existing control system and Cyber Physical System(CPS) is the systems which was converged of a computing technologies using a wired or wireless network. CPS was adopted in the future government-led technology in the United States and Europe and is being pursued in cooperation with institutes, industries, and academia. In this paper, we implement and describe a technique for controlling the system for transmitting power wirelessly by sensing method using the matching of CPS technology concepts.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.4
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• pp.431-437
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• 2019

PLC(Power Line Communication) is being used in various ways in smart grid system because of the advantages of low cost and high data throughput. However, power line channel has many problems due to impulse noise and various studies have been conducted to solve the problem. Recently, ACDL(Adaptive Cannonical Differential Limiter) which is based on an adaptive clipping with analog nonlinear filter, has been proposed and performs better than the others. In this paper, we show that ACDL is similar to the detection of slew rate with oversampled digital signal by simplification and analysis. Through the simulation under the PRIME standard it is shown that the proposed performs equal to or better than that of ACDL, but significantly reduce the complexity to implement. The BER performance is equal but the complexity is reduced to less than 10%.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.653-660
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• 2021

Renewable energy resources are rapidly becoming an integral part of electricity generation portfolios around the world due to declining costs, government subsidies, and corporate sustainability goal. Interacting wind, solar, and load forecast errors can create significant unpredictable impacts on the distribution system, feeder congestion, voltage standard and reactive power stability margins. These impacts will be increasing with the increasing penetration levels of variable renewable generation in the power systems. There is a limit to the maximum amount of renewable energy sources that can be connected in a distribution feeder by the connection rule of transmission & distribution facility in Korea. This study represents the decision plans of hosting capacity for distribution feeders without the need for significant upgrades to the existing transmission infrastructure. Especially, the paper suggests and discusses the hosting capacity standard of feeder cables and minimum load calculation of distribution feeders.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1624-1630
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• 2019

With the increase in there are smart devices penetration around the world, services related to exercise checks are attracting attention. However, there is existing exercise amount measurement service does not use the altitude information, or because the use of an algorithm that does not corrected the GPS altitude error is not accurate movement distance provided have a problem. Therefore, in this paper, to improve the existing problems, Kalman-filter-based user movement distance measurement algorithm is designed and implementation of improved by using the Kalman-filter based GPS and barometric altimeter sensor fusion algorithm to improve the altitude value the accuracy and of calculate the coordinate plane distance. As a result of comparing the designed and implementation of algorithm with the existing algorithms, it is confirmed that the proposed algorithm improves the accuracy by about 2.17%.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.21-28
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• 2021

In this study, we propose a deep learning-based NILM technique using actual measured power data for 5 kinds of home appliances and verify its effectiveness. For about 3 weeks, the active power of the central power measuring device and five kinds of home appliances (refrigerator, induction, TV, washing machine, air cleaner) was individually measured. The preprocessing method of the measured data was introduced, and characteristics of each household appliance were analyzed through spectogram analysis. The characteristics of each household appliance are organized into a learning data set. All the power data measured by the central power measuring device and 5 kinds of home appliances were time-series mapping, and training was performed using a LSTM neural network, which is excellent for time series data prediction. An algorithm that can disaggregate five types of energies using only the power data of the main central power measuring device is proposed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.109-116
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• 2021

In this paper, we propose a non-intrusive load monitoring(NILM) system which can find the power of each home appliance from the aggregated total power as the activation in the trading market of the distributed resource and the increasing importance of energy management. We transform the amount of appliances' power into a power on-off state by preprocessing. We use LSTM as a model for predicting states based on these data. Accuracy is measured by comparing predicted states with real ones after postprocessing. In this paper, the accuracy is measured with the different number of electronic products, data postprocessing method, and Time step size. When the number of electronic products is 6, the data postprocessing method using the Round function is used, and Time step size is set to 6, the maximum accuracy can be obtained.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.307-313
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• 2021

Most of the stores of small business owners are those that use a large number of electrical devices, and in particular, there are many stores that use a cold storage system. In severe cases, there is a lot of power load on the store, which can cause a loss to the assets in the store as the power supply is cut off. Accordingly, in this paper, an LSTM-based power load prediction system was designed to measure the energy demand rate of stores and to save energy. Since it can be used as a data-based power saving system for small and medium-sized stores, it is expected to be used as a data-based power demand prediction system for small businesses in the future, and to be used in the field of preventing damage due to power load.