• Journal of Institute of Control, Robotics and Systems
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• v.15 no.2
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• pp.169-175
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• 2009

A new wire detection algorithm for power line inspection by a mobile robot has been proposed in this paper. There have been a lot of studies in order to support the high-quality electric power. For the high-quality power supply, it is necessary to investigate the power lines and insulators before the lines or insulators were disconnected or damaged. Although Korea Electric power Corp. has made many efforts for the quality improvement, it is not enough to inspect all the power lines by human inspectors. According to this problem, it is decided to replace the human operators by the power line inspection robot. When the robots are used for the inspection, there could be several advantages, for example, the working efficiency and the prevention of accident. And also the shortage of human power for dangerous jobs can be resolved. In this paper, as a part of the development of power line inspection robot, DICRO, the sensor fusion and fuzzy control algorithms are developed to detect the wire and slope of the wire. The effectiveness of the proposed algorithms is proved by the real experiments with DICRO which is under development so far.

• New & Renewable Energy
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• v.8 no.4
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• pp.13-20
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• 2012

This paper describes a transformerless static synchronous campensator (STATCOM) system based on cascade H-bridge multilevel inverter with star configuration. It is designed not only for the dynamic and continuous compensation of the reactive power but also for the improvement of power quality of existing wind power plant. Especially, when the induction generator of wind turbine is directly connected to the grid, reactive power are occurred by exiting current. so a reactive power compensation system based on the cascade H-bridge multilevel STATCOM is proposed because the output power quality and controllability of reactive power are required by grid code in many different countries. Using various The proposed reactive power control strategy using a STATCOM is compared with the conventional scheme using fixed-size of capacitor bank through various simulation results.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.774-775
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• 2011

Recently, by increasing of devices which are sensitive to power quality, microprocessor and power electronics, the deterioration of power quality is accelerated. Accordingly, various methods for analysis, detection, compensation and countermeasure on power quality are proposed. For this, the study of distinction of various disturbances and fault which is occurred in power system is necessary to prior. Therefore, in this paper, the classification algorithm among steady state and single line to ground fault which is commonly occurred fault is proposed using S-Transform.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2190-2194
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• 2010

Wind power generation system (WPGS) of Ulleung Island causes frequency and voltage fluctuation due to wind speed variation during night time. Superconducting magnetic energy storage (SMES) system can overcome the fluctuations through the fast response time of energy charging and discharging. The SMES system should be connected to the terminal of the WPGS for frequency stabilization. To demonstrated the effectiveness of SMES system for power quality improvement, Ulleung Island power network was modeled in a real time digital simulator (RTDS). The RTDS-based simulation results of power quality improvement with SMES are investigated and discussed in detail.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1523-1529
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• 2010

This paper describes the distribution power system econimical PQMS(Power quality monitoring system) of Utility. Recently, the korea power quality standard has been established based on the IEC Std. By IEC Std., the power quality assessment point is measured in PCC(Point of common coupling). In this case, the utility has to construct PQM system in all customer PCC point and the PQ meter cost would be very high in order to acquire the suitable data. Also the distribution system would be encounter the communication overload problem due to the huge data. Accordingly the utilities could not apply to PQM system in the distribution power system by the cost and communication problem. In this paper, the proposed economical PQMS has the voltage and current signal reiteration function and FFT operation function is transferred the server. Also the voltage and current measurement channels are minimized by a classified substation construction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1744-1751
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• 2008

This paper presents a monitor positioning algorithm to identify the power quality event source in the distribution system with distributed generations. This algorithm determines the appropriate number of monitors and their locations considering power system topology together with distributed generation. This paper summarizes the guidelines of monitor positioning into five principles and defines the weighting factors according to the principles. To evaluate the adequacy of monitor positioning results, ambiguity indices considering monitor location and system topology are proposed. The optimal number and locations of monitors are determined from optimization routine using the weighting factors and the monitor positioning results are evaluated in terms of ambiguity indices. The algorithm is applied to IEEE 13 bus test feeder and suggests the optimal number and locations of power quality monitors. The proposed approach can realize the expert's knowledge on monitor positioning into a sophisticated automatic computing algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.6
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• pp.63-69
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• 2015

Energy Storage Systems (ESSs) are essential in the future power systems because they can improve power usage efficiency. In this paper, we propose the countermeasure for improving the power quality using coordinated control of BESS(Battery Energy Storage System) on EV connected system. To verify the performance of proposed scheme, we simulate on the actual power system of KEPCO and compare the results of voltage variation, frequency variation, and load factor with those of uncoordinated control. From the simulation results, we confirm that frequency and voltage deviation are significantly reduced with proposed coordinated control of BESS.

• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.272-277
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• 2013

Power quality is a term that is now extensively used in power systems applications, and in this context the voltage, current, and phase angle are discussed widely. In particular, different algorithms that are capable of detecting the voltage sag and swell information in a real time environment have been proposed and developed. Voltage sag and swell play an important role in determining the stability, quality, and operation of a power system. This paper presents ANFIS (Adaptive Network based Fuzzy Inference System) models with different membership functions to build the voltage shape with the knowledge of known system parameters, and detect voltage sag and swell accurately. The performance of each method has been compared with each other/other methods to determine the effectiveness of the different models, and the results are presented.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.770-771
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• 2007

Wind power plant is based on the wind energy so the active power is frequently changed and connected to grid according with wind condition. These characteristics are bed effect to distribution line. On this reserch, we want to analyze the quality of electric power synchro/asynchronous generation system in Dae Kwan Ryung wind farm. The contents of analysis are active/reactive power variation and total demand distortion and transiency and sag/swell phenomena. we hope this research can contribute to the power quality improvement.

• Journal of Electrical Engineering and Technology
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• v.5 no.1
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• pp.103-115
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• 2010

This paper discusses a DC distribution system which has been supplied by external AC systems as well as local microturbine distributed generation system in order to demonstrate an overall solution to power quality issue. Based on the dynamic model of the converter, a design procedure has been presented. In this paper, the power flow control in DC distribution system has been achieved by network converters. A suitable control strategy for these converters has been proposed, too. They have DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control system has been proposed for MT converter. Several case studies have been studied and the simulation results show that DC distribution system including microturbine unit can provide the premium power quality using proposed methods.