• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.29 no.3
• /
• pp.69-80
• /
• 2015

This paper is writing about developing magnet power supply. It is very important for power supply to obtain output current in high precision and high stability. As a switching noise and a power noise are the cause of disrupting the stability of output current, to remove these at the front end, low pass filter with 300Hz cutoff frequency is designed and placed. And also to minimize switching noise of the current into magnet and to stop abrupt fluctuations, output filter should be designed, when doing this, we design it by considering load has high value inductance. As power supply demands the stability of less than 5ppm, high precision 24bit(300nV/bit) analog digital converter is needed. As resolving power of 24bit(300nV/bit) analog digital converter is high, it is also very important to design the input stage of analog digital converter. To remove input noise, 4th order low pass filter is composed. Due to the limitation of clock, to minimize quantization error between 15bit DPWM and output of ADC having 24bit resolving power, ${\Sigma}-{\Delta}$ modulation is used and bit contracted DPWM is constituted. And before implementing, to maximize efficiency, simulink is used.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.9
• /
• pp.64-72
• /
• 2012

The interest in wind power generation area such as developing and operating wind-diesel pilot complex in remote and island regions that have difficulty in having power plant and connecting to power system is growing rapidly in the world. We have installed and researched the hybrid system in Sekgok Pilot Complex to meet the new generation system. From the monitored data of the system, the performance of each diesel power plant is outstanding. However, step out problem was detected with respect to load sharing and synchronization with decentralized power supply. An advanced controller design having better response time and stability is needed to solve such problem. In this paper, we proposed the algorithm, through digital controller of Governor, which is applied to hybrid system. As a result, we obtained the stable frequency value in variable loading conditions. Also, we proved the advanced response time and stability through the simulation and experiment by applying additional current signal to the control algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.2
• /
• pp.148-154
• /
• 2008

The power transfer capability has been recently highlighted as a key issue in many utilities. The total transfer capability in the KEPCO power system is determined mainly by the voltage stability limit and an enormous number of contingencies should be analyzed to determine the total transfer capability. In this paper, a new ranking index for determining the total transfer capability from voltage stability point of view is presented. This index is applied to the practical system of KEPCO and the effects of ranking the contingencies are analyzed by use of PSS/E package and a developed IPLAN program.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.10
• /
• pp.41-49
• /
• 2013

There is a wide variety of system and applications in the power system. However, they have compatibility issues because they use different data standard and communication method. With the introduction of the smart grid, power system has been grow and diversified. Therefore power system need to be compatible with each other and the interoperability between applications is increasingly important. Thus, the IEC established IEC61970 and CIM Standard data exchange model for interoperability and system integration. Server-Client system was constructed which using CIM HSDA(Part4), a standard communication model, presented in IEC 619710. Also, self-developed real-time voltage stability analysis application and contingency analysis application was used. CIM HSDA was used for data input and real-time analysis. Tolerance of result which is in the range of allowable derived by Perform real-time voltage stability and contingency analysis of Jeju power system, and then compare it's result with PSS/E result.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.10
• /
• pp.1728-1737
• /
• 2003

The vertical lathe is a very popular machine tool in modem manufacturing industries because of its small area of installation. The small installation area is highly desirable for the flexibility improvement of the manufacturing systems such as FMS, CIM, and IMS. The vertical lathe, however, has much taller height compared to the traditional horizontal lathe, and consequently more severe vibrations. In this study, the structure of a vertical lathe is analyzed to investigate the dynamic properties and further to establish some ideas of the design alteration for the improved dynamic stability even at the higher operating speed. The simulation model is implemented to apply those design alterations for the optimization. The result of this study is not only prosperous but also ready to be applied to the optimum design of various machine tool structures for the improved stability.

• International Journal of Highway Engineering
• /
• v.2 no.4 s.6
• /
• pp.123-131
• /
• 2000

The compaction equipment and the Marshall stability head are the two important testing equipment for the Marshall test. The compaction equipment is closely related to the air void, VMA and compactability of the mixtures, and the stability head is related to the Marshall stability and the flow, therefore the size and the shape of the equipment is essential for finding the accurate optimum asphalt content for the asphalt mix design. However, the size and the shape of the equipment currently used and the condition of the installation of compaction pedestal in this country are different from each agency and manufacturer. The national inspection of the Marshall equipment is necessary because the difference can affect the test results and also the performance of the asphalt pavement.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.3
• /
• pp.18-24
• /
• 2003

This paper presents a power transfer capability calculation algorithm considering voltage stability margin. In this method, voltage stability margin constraints are incorporated into a power transfer capability formulation to guarantee adequate voltage security levels in an interconnected power system The proposed method is applied to IEEE-24 reliability test systems and the results show the effectiveness of the method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.5
• /
• pp.83-89
• /
• 2002

The purpose of this paper is to assess experimentally system stability of the 154［㎸］transmission system due to the current of the forthcoming AC High-Speed Railway (HSR) era. It introduces a simple method to evaluate the system stability. The proposed method also shows the relationship between stability and power losses, and the stability indices made by the numerical process proposed in this paper will be used to assess whether a system can be stabilized or not. This paper also presents the improvement of the stability via loss reduction using a shunt compensator. Reactive power compensation is often the most effective way to improve both power transfer capability and system stability. The suitable modeling of the traction power system should be applicable to the PSS/E. The proposed method is tested on a practical system which will be expected to accommodate the heavy HSR load.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.4
• /
• pp.17-24
• /
• 2010

The power transfer capability has been recently highlighted as a key issue in many utilities with the power system more stressed and heavy loaded. The total transfer capability in the KEPCO power system is determined mainly by the voltage stability limit and many approaches for enhancement of the total transfer capability has been consistently performed. In this paper, a new transfer capability index to locate the STATCOM(Static Synchronous Compensator) effectively for enhancing the total transfer capability from a static voltage stability viewpoint is presented and it is applied to a small scale power system of IEEE 39-bus test system in order to show the effects of this index. In addition, the effect of transient stability as well as voltage stability to the total transfer capability when loads are increased is analyzed using this small scale power system.

• Proceedings of the KIEE Conference
• /
• 1992.07b
• /
• pp.775-778
• /
• 1992

In 1980, 154kV OF cable was installed at the Cheong-Pyeong pumped-storage power station. Effective head of this pumped-storage station is 250m between upper and lower re-servior and length of cable route is 750m. However, several failures have happened owing to steep slope during the operation. 154 kV XLPE cable was applied for this power station to eliminate a lack of stability on account of steep slope and successfully installed in 1991. Meanwhile, installation procedure brings about many problem to be solved. In this paper, we describe the counter measure of cable sliding phenomena caused by heat shrinkage as well as the method of installation of cable under the steep slope condition. And hereafter, we think this paper will be a good reference to design and installation of 154kV XLPE cables in steep slope turnnel at urban areas.