• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.982-996
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• 2016

In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.498-503
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• 2010

Recently, the industrial electric customers require a digital switchgear which can improve the safety and reliability of the power supply, and the quality of electric power by on-line monitoring the electric power information based on the internet under the ubiquitous environments. Accordingly, in this paper, a industrial switch-gear prototype is designed based on the power supply method of three phase, four-line type, and then a three-phase electric management module of the digital switchgear is made for industrial electric customer system. Finally, the three-phase voltage and current measuring function of the prototype is verified from real power load test.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.663-665
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• 2000

For the control system of thermal turbine in fuel and nuclear power plant, as high reliability and availability are required, redundant control system is generally applied. This paper presents the configuration and design of such a redundant control system that can be suitable for control and monitoring of the turbine. System components such as I/O system, communication networks, voting system are designed, and especially the new intelligent voter using serial communication are proposed. The characteristics of the implemented control system is independence of the control, protection and monitoring functions, and discrimination of the redundancies, and high availability. The control functions such as speed control, load control, valve control and protective functions such as overspeed and PLU are designed in detail.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.543-544
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• 2007

This paper introduce methods and analysis of a simple wireless sensor concept for detecting and locating faults as well as for load monitoring are presented. The concept is based on distributed wireless sensors that are attached to the incoming and outgoing power lines of secondary substations. A sensor measures only phase current characteristics of the wire it is attached to, is not synchronized to other sensors and does not need configuration of triggering levels. The main novelty of the concept is in detecting and locating faults by combining power distribution network characteristics on system level with low power sampling methods for individual sensors. This concept enables the sensor design to be simple, energy efficient and thus applicable in new installations and for retrofit purposes in both overhead and underground electrical distribution systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.896-899
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• 2016

Server management and power management are important to operate a data center stably and efficiently. By this paper, we introduce an web based application that is able to monitor and visualize energy consumption, help to energy consumption analysis of a data center due to provide server monitoring information such as temperatures for server, status of each device, power status using server management interfaces and power management modules in data center, also suggest the methods to implement them. This application takes advantage of IPMI which is server management standard interfaces and server management technology in manufacturer's individual way so it can do integrated monitoring for heterogeneous severs, and there is little monitoring load inside of server system because it doesn't need to install agent program for monitoring target system, and it can be used successfully to energy consumption analysis, server management in a data center due to realtime provided energy consumption and monitoring information.

• Journal of Wind Energy
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• v.2 no.1
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• pp.90-96
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• 2011

The purpose of this paper is to describe the control system for optimal performance of 2MW gearless PMSG wind turbine system, and to afford some techniques of the algorithm selection and design optimization of the wind turbine control system through analysis of load calculation and control characteristic. Wind turbine control system is composed of the main control system and remote control and monitoring system. The main control system is industrial PC based controller, and the remote control and monitoring system is a server based computer system. The main control system has a supervisory control of the wind turbine with operation procedures and power-speed control through the torque control by pitch angle. There are some applications to optimize the wind turbine system at the starting mode with increasing of rotor speed, and cut-in operating mode to prevent trundling cut-in and cut-out, a gain scheduling of pitch PID controller, torque scheduling and limitation of generation power by temperature limitation or remote command by remote control and monitoring system. Also, the server operation program of the remote control and monitoring system and the design of graphical display are described in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.992-995
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• 1996

The major roles of Power SCADA System are continuous monitoring of electrical equipments state, real-time data processing and dispatching. Especially, SCADA system demands fast response time in heavy load condition, high reliability, fault tolerance, expansion capacity for the future. According to developing computer system technology, SCADA system is changing system configuration from centralized processing system to distributed processing system. This paper describes operational benefits, problems and improvement (which is studying in theory) in the application of Open System Architecture SCADA which has been installed since 1994, Seoul regional control center in KEPCO.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.155-163
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• 2013

As the increasing HIF(High Impedance Fault) with the arc cannot be easily detected for the low fault current magnitude compared to actual load in distribution line. However, the arcing current shows that the magnitude varies with time and the signal is asymmetric. In addition, discontinuous changes occur at starting point of arc. Considering these characteristics, wavelet transformation of actual current data shows difference between before and after the fault. Althogh raw data(detail coefficient) of wavelet transform may not be directly applied to HIF detection logic in a device, there are several developing methods of HIF monitoring data using the original wavelet coefficients. In this paper, a simple and effective developing methods of HIF monitoring data were analized by using the signal data through an actual HIF experiment to apply them to economic devices. The methods using the sumation of the wavelet coefficient squares in one cycle of the fundamental frequency as the energies of the wavelet coefficeits and the sumation of the absolute values were compared. Besides, the improved method which less occupies H/W resouces and can be applied to field detection devices was proposed. and also Verification of this HIF detection method through field test on distribution system in KEPCO power testing center was performed.

• Journal of Information Processing Systems
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• v.16 no.3
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• pp.733-741
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• 2020

A smart dust monitoring system is useful for obtaining information on rough terrain that is difficult for humans to access. One of ways to deploy sensors to gather information in smart dust environment is to use an aircraft in the Amazon rainforest to scatter an enormous amount of small and cheap sensors (or smart dust devices), or to use an unmanned spacecraft to throw the sensors on the moon's surface. However, scattering an enormous amount of smart dust devices creates the difficulty of managing such devices as they can be scattered into inaccessible areas, and also causes problems such as bottlenecks, device failure, and high/low density of devices. Of the various problems that may occur in the smart dust environment, this paper is focused on solving the bottleneck problem. To address this, we propose and construct a three-layered hierarchical smart dust monitoring system that includes relay dust devices (RDDs). An RDD is a smart dust device with relatively higher computing/communicating power than a normal smart dust device. RDDs play a crucial role in reducing traffic load for the system. To validate the proposed system, we use climate data obtained from authorized portals to compare the system with other systems (i.e., non-hierarchical system and simple hierarchical system). Through this comparison, we determined that the transmission processing time is reduced by 49%-50% compared to other systems, and the maximum number of connectable devices can be increased by 16-32 times without compromising the system's operations.

• International Journal of Advanced Culture Technology
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• v.2 no.2
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• pp.11-14
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• 2014

In the smart grid, it will be possible to communicate with the consumers for the purposes of monitoring and controlling their power consumption without disturbing their business or comfort. This will bring easier administration capabilities for the utilities. On the other hand, consumers will require more advanced home automation tools which can be implemented by using advanced sensor technologies. For instance, consumers may need to adapt their consumption according to the dynamically varying electricity prices which necessitates home automation tools. This paper tries to combine neural network and nonlinear autoregressive with exogenous variable (NARX) class for next week electric load forecasting. The suitability of the proposed approach is illustrated through an application to electric load consumption data. The suggested system provides a useful and suitable tool especially for the load forecasting.