• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.1-8
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• 2016

The characteristics of Korean power systems are large capacity of generation sites and concentrated load in Seoul metropolitan area. According to the national generation facility plan, more generation facilities are needed to be constructed as the electrical demands are forecasted to increase. Moreover, the size of generation sites are expected to increase, too. Therefore transient stability problems become worse and worse. Recently, the necessity of HVDC has been raised to overcome the difficulty of constructing HVAC transmission lines. This paper shows the analysis of transient stability when HVDC transmission system is added to the power system consisting of large generation sites.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.23-28
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• 2015

Two old synchronous condensers in Jeju are being replaced by new machines to operate Jeju AC network with Haenam-Jeju HVDC system stably. Before new synchronous condensers operate on site, voltage stability analysis is conducted to verify stable operation of jeju AC network. Through impedance analysis of the synchronous machine, transformer and ac network, the equivalent circuit is constructed and the voltage drop during start-up is calculated. Then, PSS/E fault analysis is performed to acquire short-circuit capacity according to the generator operation scenarios. Voltage variation when starting synchronous condenser is simulated in PSCAD/EMTDC and satisfies the operating condition of jeju AC network and HVDC #1 system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.4
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• pp.682-693
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• 1988

In this paper, a method of dynamic modeling is proposed for a hydraulic power transmission with Merrite-Wilson gear train and a computer simulation program for dynamic analysis of the power transmission is developed. Using this computer program the transient characteristics during the gear change are observed and the influence of transmission design parameters and hydraulic control parameters are analysed. Through this result of study a criteria for the good shift quality is derived.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.353.2-353
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• 2002

The attenuation of waves transmitted through non-conservative joints that are shown in many practical structures, is affected by the impedance and the orientation of the joint. In this paper, the joints between plate structures are assumed to be modeled as linear spring-dashpot systems and the transmission and reflection of vibration energy in the medium to high frequency ranges are investigated. (omitted)

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.31-39
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• 2013

Proper installation of Flexible AC Transmission Systems (FACTS) devices in existing transmission networks can enable power systems to accommodate more power transfer with less network expansion cost. The problem to maximize transmission system loadability by determining optimal locations and settings for installations of two types of FACTS devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), is formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). For solving the MDCP, in the paper, the proposed method with fitness sharing technique involved in the updating process of the particle swarm optimization (PSO) algorithm, can diversify the particles over the search regions as much as possible, making it possible to achieve the optimal solution with a big probability. The modified IEEE-14 bus network and a practical power system are used to validate the proposed method.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.696-701
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• 2000

In this study, a mathematical model fur analyzing the shift characteristics is proposed. The proposed model comprises power transmission system and vehicle system, which are coupled. And On-road car test is carried out in order to extract model parameters. Tile model is composed of a detailed powertrain, an engine/AT housing, a simplified suspension system. tires and a vehicle body model. On the test, the vehicle accelerations and pitch ratio are measured by using accelerometers and gyro sensor. The other data, for example speeds, a throttle position and a brake signal, are taken from sensors which already exist in the vehicle. Using natural frequency and characteristic equation, vehicle model parameters are extracted from experimental data.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.228-230
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• 2006

This paper describes the information transmission method using communication networks between the devices in Photovoltaic Power System, and also represents the test result which carried out in the field. In this test, transmission signal waveform, polling time, response time and request/response frame were measured between the devices. The measured results show the excellent transmission characteristics.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.10
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• pp.593-601
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• 2003

Distance realy is tripped by the line impedance calculated at the relay point. Accordingly the accurate operation depends on the precise calculation of line impedance. Impedance can be accurately calculated in case of overhead line. However, in case of power cables or combined transmission lines, impedance can not be accurately calculated because cable systems have the sheath, grounding resistance, and sheath voltage limiters(SVLs). There are also several grounding systems in cable systems. Therefore, if there is a fault in cable systems, these terms will severely be caused much error to calculation of impedance. Accordingly the proper compensation should be developed for the correct operation of the distance relay. This paper presents the distance calculating algorithm in combined transmission line with power cable using wavelet transform. In order to achieve such purpose, judgement method to discriminate the fault section in both sections was proposed using D1 coefficient summation in db4. And also, error compensation value was proposed for correct calculation of impedance in power cables section.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.44-47
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• 2001

In a competitive environment of electric power industy, the level of uncertainty increase due to generation investment decisions creating new challenge to transmission system planner. The use of a locational signal and the provision of a indicative plan to control the generation investment reasonably is very important in the viewpoint of a regulator. The main target of this stuty is to emphasize on the necessity for considering simultaneously both generation and transmission expansion plan. This paper demonstrate the many case studies to make certain of the necessity for the interconnection between generation and transmission planning. In addition to, the planning in Korea power industry is considerd.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1810-1812
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• 1997

This paper describes the results of ground fault analysis on HVDC Transmission Line using TNA (Transient Network Analyzer). The maximum overvoltage is about 1.7 p.u. in the case of single line to ground fault on the overhead transmission line. When the cable is linked to the end of the overhead transmission line, the maximum overvoltage is about 1.58 p.u..