• 한국정밀공학회지
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• 제13권9호
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• pp.149-155
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• 1996

Recent researches in the trouble monitoring system of grinding process have emphasized the use of deep knowledge. Such works include the monitoring and diagnostic systems for cylindrical grinding using sensors on chatter vibration and grinding burn during the process. But, since grinding operations are especially related with a lalrge amount of ambique parameters, it is effectively difficult to detect the grinding troubles occuring during the grinding process. In this paper, monitoring system for grinding utilizes the neural networks based on grinding power signatures. The monitoring system of grinding operations, which makes use of PDP neural networks, is presented. Then, the implementation results by computer simulations and experimental data with respect to chatter vibration and grinding burn are compared.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.101-108
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• 2007

State estimators are used to monitor the operating states of power systems in modern EMS. It iteratively calculates the voltage profile of the currently operating power system with voltage, current, and power measurements gathered from the entire system. All the measurements are usually assumed to be obtained simultaneously. It is practically impossible, however, to maintain the synchronism of the measurement data. Recently, phasor measurements synchronized via satellite are used for the operation of these power systems. This paper describes the modified state estimator used to support the processing of synchronized phasor measurements. Synchronized phasor measurements are found to provide synchronism of measurement data and improve the accuracy/redundancy of the measurement data for state estimation. The details of the developed state estimation program and some numerical results of operation are presented.

• 한국멀티미디어학회논문지
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• 제23권9호
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• pp.1171-1180
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• 2020

The number of the PV systems installed in south korea has been gradually increasing. Interest of operation & management of PV System is rising up as PV System installation trends to increase. The vital function of operation & management is the monitoring system. Most monitoring systems are only available for equipment of suppliers and manufacturers. In this study, a monitoring system was implemented to support multi-domain equipment (inverter, junction box, water distribution board, environmental sensors) that are not limited to specific manufacturers. Monitoring system includes a visualization function, which makes it easy for users to check the power generation and the operation status of the equipment of PV System. In the future, this monitoring system will be utilized as an operation & maintenance foundation element in the PV system industry.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1812-1824
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• 2019

The location and human activity are usually used as one of the important parameters to monitor the health status in healthcare devices. However, nearly all existing location and monitoring systems have the limitation of short-range communication and high power consumption. In this paper, we propose a new mechanism to collect and transmit monitoring information based on LoRa technology. The monitoring device with sensors can collect the real-time activity and location information and transmit them to the cloud server through LoRa gateway. The user can check all his history and current information through the specific designed mobile applications. Experiment was carried out to verify the communication, power consumption and monitoring performance of the entire system. Experimental results demonstrate that this system can collect monitoring and activity information accurately and provide the long rang coverage with low power consumption.

• 전력전자학회논문지
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• 제24권1호
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• pp.62-65
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• 2019

Wireless power transfer systems require an algorithm to determine the presence of the target object for mitigating standby power and safety issues. Although many schemes that sense various external objects have been actively proposed for inductive power transfer systems, not many studies on capacitive power transfer systems have been conducted compared with those on inductive power transfer systems. This study proposes a target object detection algorithm by monitoring the capacitance in transmitter-side electrodes without additional pressure sensors or distance sensors. The proposed algorithm determines the presence of a target object by monitoring the change in capacitance in transmitter-side electrodes using the step pulse of the microcontroller unit. The algorithm is verified by two step processes. First, the performance in capacitance measurement is compared with that of an LCR meter. Then, the verification is conducted in a 5-W capacitive power transfer hardware. Experimental result shows that the interelectrode capacitance increases by 6 times when the target object is fully aligned. Thus, the proposed scheme can successfully detect the presence of the target object.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.127-130
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• 2002

Recently, with the increasing use of power semiconductors and microprocessors which are very sensitive to little change of power quality and for coping positively with anticipating power quality disputes between power providers and consumers which are possible to occur by of power market being formed, the power quality problem has gained preponderance among the contemporary research areas. To serve these purposes, the integrated system has been researched and developed for power quality analysis and monitoring, which provides speedy and powerful functions by the growth of computer hardware and information technology. But the advent of fast and lower price hardware make little difference in an application on many systems. As a result, the key issues of constructing power quality monitoring system are in the management of data obtained, accurate algorithms, graphic representation and user-friendly-environment for easy and clear analysis results. So, in this paper it will be introduced that the standard of user-friendly-GUI(Graphic User Interface) and analysis graphic representation for intuitive understanding of results from power quality analysis based on consideration of several systems currently being in use.

• 전기학회논문지
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• 제59권3호
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• pp.506-514
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• 2010

Defense systems are needed to prevent catastrophic failures of a power grid due to cascaded events. Cascaded events can be occurred by power flow overload. Especially, it is the most dangerous problem that overload line is outage, because it can make the power system face danger of cascaded. In this paper, vulnerability evaluation for monitoring wide are outage is proposed using by configuration information of transmission systems. This method of vulnerability evaluation is considered direct effect and indirect effect of power flow, especially overload. What is more, it can be used when the configuration of power system changes, as simple fault occurs or maintenance of facility. In the case studies, the estimation and simulation network have been testified and analysed in PSSE and C programming.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.103-105
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• 2008

In, this paper, we consider the relation between on-line monitoring and diagnostics on the one hand and high-voltage (HV) withstand and partial discharge (PO) on-site testing on the other. HV testing supplies the basic data (fingerprints) for diagnostics. In case of warnings by on-line diagnostic systems, off-line withstand and PO testing delivers the best possible information about defects and enables the classification of the risk. Because alternating voltage (AC) is the most important test voltage, the AC generation on site is considered. Frequency tuned resonant (ACRF) test systems are best adapted to on-site conditions. They can be simply combined with PO measuring equipment. The available ACRF test systems and their application to electric power equipment -from cable systems to power transformers - is described.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.111-114
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• 2008

The paper considers the relation between on-line monitoring and diagnostics on the one hand and high-voltage (HV) withstand and partial discharge (PD) on-site testing on the other. HV testing supplies the basic data (fingerprints) for diagnostics. In case of warnings by on-line diagnostic systems, off-line withstand and PD testing delivers the best possible information about defects and enables the classification of the risk. Because alternating voltage (AC) is the most important test voltage, the AC generation on site is considered. Frequency tuned resonant (ACRF) test systems are best adapted to on-site conditions. They can be simply combined with PD measuring equipment. The available ACRF test systems and their application to electric power equipment -from cable systems to power transformers - is described.

• Advances in Energy Research
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• 제7권2호
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• pp.123-134
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• 2020

Photovoltaic systems are progressively attached importance and their installed capacity increases day by day because of their reliability, decremented installation and operating cost and simple construction structure. Generated power obtained from a photovoltaic system changes depending upon regional distinctness, and It can be estimated approximately by taking into consideration mean global radiation amount, temperature and humidity. However, there may be different regional negative or positive factors like dust, air pollution, desert powder which affect generated power. The best reliable data for a region can be obtained from the existing photovoltaic system in the region. For this purpose, a monitoring system for 1000W monocrystalline photovoltaic system constructed at Kocaeli University Uzunciftlik Nuh Cimento Vocational High Scholl is prepared. The installed monitoring system shows and records real values generated from the photovoltaic system and environmental data. In the study, Instantaneous data obtained from the monitoring system for October 2018 and 7th October 2018 is given within figures. Additionally, daily and monthly total energy productions of the photovoltaic system are given for October 2018 and date interval between July 2018 and March 2018, respectively.