• Title, Summary, Keyword: maximum permissible power

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Analysis of Safety Distance and Maximum Permissible Power of Resonant Wireless Power Transfer Systems with Regard to Magnetic Field Exposure

  • Park, Young-Min;Byun, Jin-Kyu
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.450-459
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    • 2015
  • In this paper, the safety distances and maximum permissible power (MPP) of resonant wireless power transfer systems are defined and derived with regard to human exposure to electromagnetic field (EMF). The definition is based on the calculated induced current density and electric field in the standard human model located between the transmitting and receiving coil. In order to avoid the adverse health effects such as stimulation of nerve tissues, the induced current and electric field must not exceed the basic restriction values specified in EMF safety guidelines. The different combinations of diameters of the coils and the distance between the two coils are investigated and their effects are analyzed. Two versions of EMF safety guidelines (ICNIRP 1998 and ICNIRP 2010) are used as bases for safety distance calculation and the difference between the two guidelines are discussed.

A Study on the Calculation of Transmission Current-Carrying Capacity by Horizontal Arrangement Type in the Installation Methods of 154kV XLPE 600㎟ Power Cable Buried Ducts in Ground (154kV XLPE 600㎟ 지중관로 수평배열 형태별 허용전류용량 산정에 관한 연구)

  • Kim, Se-Dong;Yoo, Sang-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.30 no.3
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    • pp.53-58
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    • 2016
  • The underground transmission lines which have been built to expand the suppling facilities will be continuously accompanying with high growth of the increase of power demand in the metropolitan area in recent years. So, it is necessary to maximize the ability and reliability of power supply with the current-carrying capability of the underground transmission lines. Design criteria of KEPCO is to be presented and used frequently. But it has to be studied about the installation methods of power cable buried in ground. In this study, we used the program for calculating the current-carrying capability of underground transmission power cables. We estimated the maximum permissible current values by the horizontal arrangement in the installation methods of power cable(154kV XLPE $600mm^2$) buried ducts in ground. To see the general tendency of the analysis, we researched a statistical analysis with such parameters as the maximum permissible current values. Through the regression analysis, we analyze the most highly values of the maximum permissible current on the Ra type duct arrangement.

Calculation of the Harmonic Emission Limit for low-Voltage Electrical Equipment (국내 저압 전기기기의 고조파 유출 제한값 산정)

  • Kang, Moon-Ho;Song, Yang-Hoi;Lee, Heung-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.10
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    • pp.56-61
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    • 2008
  • Because the harmonic disturbance characteristic which makes voltage drop and the deterioration of instantaneous power quality in electrical power system overheats the NGR and the customer capacitor and malfunctions the OCGR and AMR, it is necessary for electric power company to take active measures to reduce this disturbance. International Electrotechnical Commission(IEC) 61000-3-2 specifies limits for harmonic current emissions generated by low voltage(LV) electrical equipment whose input current $\leq$ 16(A) per phase. Analysis shows that limits for Class A equipment in IEC are calculated using the reference impedance of LV system and maximum permissible voltage and limits for other Classes are also calculated based on limits for Class A. Therefore we have calculated four(4) internal limits for LV electrical equipment using the korea reference impedance and maximum permissible voltage in this paper.

Determination of Derived Release Limits by the Concentration Factor Method (농축인자법에 의한 유도방출 기준 설정)

  • Byung Woo Kim;Byeung Kyu Kim;Jeong Ho Lee
    • Nuclear Engineering and Technology
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    • v.17 no.4
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    • pp.267-278
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    • 1985
  • Some kinds of methods have been applied to regulate the exposure doses by the radioactive effluents from nuclear power plants. The essential one is primary dose equivalent limit recommended by the ICRP. When the primary limit cannot be applied directly for regulation, there have been dose equivalent index in case of external exposure, or maximum permissible concentration, annual limit on intake, derived air concentration and maximum permissible body burden in case of internal exposure. But the derived limit is required from the viewpoint of discharge, for those values are inadequate to control discharge rate directly. This study was carried out to derive the release limit for the Wolsung nuclear power plant by the concentration factor method. This method is based on the assumption of steady state transfer between environment compartments.

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Measurement of Electrophysiological Changes Caused by Electromagnetic Radiation Absorbed in Biobody (전자파에 노출된 생체의 전기 생리적 변화의 측정)

  • Ju-Tae Park
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.4
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    • pp.353-362
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    • 1996
  • In this paper, SAR distribution is calculated according to the rabbit's head using approximation of its medium three layers model. Our experiment was classified 5 groups dependent on the power intensity of 2,450MHz microwave to measure EEG(Electroencephalograph) of rabbit, which was checked in left frontal lobe before and after irradiation of microwave. In results, mean total power of EEG was slightly decreased and mean composition percentages of $\theta$, $\delta$ and $\beta$ wave were increased after irradiation in observation. It means to decrease of elect- rophysiologic activity and trend of fast wave in brain after irradiation of its microwave. We analyzed the electrophysiological effect of the biobody quantitatively using measured EEG and estimated MPE (Maximum Permissible Exposure).

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Evaluation on the radio influence voltage of ${7^1/2}$ pin type domestic insulators (국산 핀애자의 라디오 방해 전압(RIV) 평가)

  • 양배덕
    • 전기의세계
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    • v.25 no.6
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    • pp.65-68
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    • 1976
  • For the RIV characteristics test of power apparatus, an indoor measuring system of radio influence voltage was set up and by means of this measuring unit SIV characteristics on the 7$^{1}$2/" pin-type domestic insulators were examined. According to the test data, RIV values of all the test pieces exceeded the maximum permissible level at 10kV applied voltage. The electrical resistivity of domestic semi-conductive glaze as good as importedone but un-uniformity of coating is turned out to be a main cause of failure.lure.

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System-Level Vulnerability Analysis for Commutation Failure Mitigation in Multi-infeed HVDC Systems

  • Yoon, Minhan;Jang, Gilsoo
    • Journal of Electrical Engineering and Technology
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    • v.13 no.3
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    • pp.1052-1059
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    • 2018
  • This paper deals with commutation failure of the line-commutated converter high voltage direct current (LCC HVDC) system caused by a three phase fault in the ac power system. An analytic calculation method is proposed to estimate the maximum permissible voltage drop at the LCC HVDC station on various operating point and to assess the area of vulnerability for commutation failure (AOV-CF) in the power system based on the residual phase voltage equation. The concept is extended to multi-infeed HVDC power system as the area of severity for simultaneous commutation failure (AOS-CF). In addition, this paper presents the implementation of a shunt compensator applying to the proposed method. An analysis and simulation have been performed with the IEEE 57 bus sample power system and the Jeju island power system in Korea.

Application a Loop Compensation type 2-DOF PID Controller tuned by Neural Network to Gas Turbine Control Loop (가스터빈 제어 루프에 대한 신경망 튜닝 루프 보상형 2-자유도 PID 제어기의 응용)

  • Kim, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • pp.781-786
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    • 1998
  • Since a gas turbine is still a significant contributor to peak time, it is very important to tune the gains of P. I. D to get a maximum power and stability within permissible limits. In the gas turbine, the main control loop must adjust the fuel flow to ensure the correct output power and frequency. but it is not easy, because the control loop is composed of many subsystems. In this paper we acquire a transfer function based on the operations data of Gun-san gas turbine and study to apply a loop compensation type 2-DOF PID controller tuning by neural-network to control loop of gas turbine to reduce phenomena caused by integral and derivative actions through simulation. We obtained satisfactory results to disturbances of subcontrol loop such as, fuel flow, air flow, turbine extraction temperature.

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Improved driving characteristics of PMSM with field-weakening region based on DSP (DSP에 의한 약계자영역 영구자석 동기전동기의 개선된 운전특)

  • Yoon, Byung-Do;Lee, Byung-Song;Kim, Choon-Sam
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.1
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    • pp.74-80
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    • 1996
  • This paper describes current controlled PWM technique of PM synchronous motors for a wide variety of speed control applications. They are however limited in their ability to operate in the power limited regime where the available torque is reduced as the speed is increased above its base value. This paper reviews the operation of the PMSM drives when they are constrained to be within the permissible envelope of maximum inverter voltage and current to produce the rated power and to provide this with the highest attainable rotor speed. The optimal field-weakening control algorithm is the use of phase current and d-axis current feedback to reduce of error between the d-axis current command and real current and to improve the torque characteristics. The improved torque characteristics of speed control strategy with optimal field weakening control algorithm is analyzed and the performance is investigated by the computer simulation and experimental results. (author). refs., figs.

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Behavior of Single Pole Foundation using Experimental Study (실증시험을 통한 강관주기초의 거동특성)

  • Kim, Dae-Hong;Oh, Gi-Dae
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.598-604
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    • 2010
  • The drilled pier foundation is widely used to support transmission line structures due to its simplicity of construction. When this foundation type is used in conjunction with a single shaft or H-frame structure, it is subjected to a high overturning moment, combined with modest vertical and shear loads. Since the length and diameter of drilled piers are often governed by a maximum permissible deflection, many drilled piers being installed today are very conservatively designed. In this study, Nine prototype field-tests (1/8 scale) have been conducted in order to determine the vertical and lateral resistance of drilled pier foundation for single pole structures. These test results reveal the test piers behaved essentially as rigid bodies in soil (6D) and the center of rotation of the pier were typically 0.6~0.4 of the pier depth below ground surface. Test results also show the relationship between the applied load and the deflection at the top of the pier is highly nonlinear.

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