• Journal of the Korean Institute of Navigation
• /
• v.21 no.2
• /
• pp.69-75
• /
• 1997

A modern electric system located at a certain distance from the discharge may respond with unexpected sensitivity, when an electrostatic discharge (ESD) phenomenon occurs heteronomously between metallic objects. For analyzing the transient electromagnetic fields caused by ESD, two resistance formulas - Toepler and Rompe-Weizel -are introduced. The experimental result given by Wilson-Ma are used to compare which of these resistance formulas is proper.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.34D no.12
• /
• pp.1-7
• /
• 1997

Serious troubles may occur in electromagnetic equipments due to electrostatic discharge (ESD). The number of the damaging incidents are significantly increasing with the increased use of integrated semiconductor elements with loer operation pwoer. In order to examine the phenomena theoretically, this paper anlyzes properties of the transient electromagnetic fields rdiated by ESD. A new model is presented using the Rompe-weizel formula for the spark resistance. The numerical results of ESD fields are compared with the experimental data that were given by wilson-Ma.

• Journal of Electrical Engineering and Technology
• /
• v.2 no.3
• /
• pp.306-311
• /
• 2007

The transient fields generated during switching operations in a Gas Insulated Substation (GIS) are associated with high frequency components in the order of few tens of MHz. These transient fields leak into the external environment of the gas-insulated equipment and can interfere with the nearby electronics. Measurements of the transient fields are thus required to characterise the interference caused by switching phenomena in such substations. In view of the above, E-field emission measurement during a switching operation has been carried out for a 245 kV GIS model, using a resonant dipole antenna and D-dot sensor. The characteristics of the E-fields i.e., frequency spectra and their levels have been analysed and are reported in the paper. Suitability of the measurements has been confirmed by comparing frequency spectra of the measured and computed transient fields.

• Proceedings of the KIEE Conference
• /
• 2004.11a
• /
• pp.255-257
• /
• 2004

This paper was studied electromagnetic field distribution and damping of PD(Partial Discharge) signal in GIS(Gas Insulated Switchgear). Cut-off frequency of electromagnetic wave propagation modes were computed, electromagnetic field distribution of propagation modes in GIS by FEM(Finite Element Method) were simulated and simulated damping characteristic of electromagnetic waves in GIS by EMTP(Electromagnetic Transient Program) when generated PD pulse. Frequency band of $TE_{mn}/TM_{mn}$ modes were determinated by simulation results of electromagnetic field distribution and were discussed optimal position of UHF sensor from this results. Equivalent circuit was used to simulate signal damping of PD pulse in GIS by EMTP and compared with measured results in laboratory of KERI.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.4
• /
• pp.185-191
• /
• 2003

In this Paper, we propose an accurate and stable solution of the transient electromagnetic response from three-dimensional arbitrarily shaped conducting objects by using a time domain magnetic field integral equation. This method does not utilize the conventional marching-on in time (MOT) solution. Instead we solve the time domain integral equation by expressing the transient behavior of the induced current in terms of temporal expansion functions with decaying exponential functions and Laguerre·polynomials. Since these temporal expansion functions converge to zero as time progresses, the transient response of the induced current does not have a late time oscillation and converges to zero unconditionally. To show the validity of the proposed method, we solve a time domain magnetic field integral equation for three closed conducting objects and compare the results of Mie solution and the inverse discrete Fourier transform (IDFT) of the solution obtained in the frequency domain.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2001.11a
• /
• pp.59-64
• /
• 2001

Transient in an electrical system are generated by lightning and switching. This paper presents analysis of switching and lightning surge, and means of limiting the voltage magnification transient for high voltage power systems by using EDSA's EMTAP software package. One means of limiting the voltage magnification transient is to convert the end-user power factor correction banks to harmonic filters. An inductance in series with the power factor correction bank was used to decrease the transient voltage at the customer bus to acceptable levees. The interception of the impulse from the phase wire is fairly straight forward by properly installed surge arresters. The simulation shows that the addition of the surge arrester at the customer location can achieve a substantial reduction of the transient magnitude.

• 전기의세계
• /
• v.21 no.4
• /
• pp.15-21
• /
• 1972

For the conventional DC machine, the armature MMF is negligible compared with field MMF except when the machine is under heavy load or transient conditions. During the motor starting or reversal, the transient armature current and corresponding MMF effect the flux density of each pole in the machine magnetic circuit. However, the circuit flux density is restored to normal values by the field winding MMF after the transient armature current dies in an electromagnetic DC motor. Permanent magnet servomotor have no field windings about the circuit poles to restore circuit flux density through the demagnetized part of each pole after the transient armature MMF dies, and portions of the magnetic circuit stay permanently demagnetized. Thus the problem of stabilizing a magnet pole piece under the influence of the transient armature current need attentions. This work present the recoil operation of the servomotor with PM poles in conjunctions with the influence of the armature reaction effect. The development of an analytical and quantatative study is presented for predicting the regime of the recoil operation under this condition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.14 no.6
• /
• pp.18-25
• /
• 2000

This paper describes the design and fabrication of a home-panel board for electromagnetic compatibility which can protect home-electric appliances from transient voltages and power line noise. The proposed panel board include a transient voltage blocking device and a EMI filter which consisted of varistors, capacitors, and bus line inductance.A performance test of the prototype panel board, blocking characteristics to transient voltages and reduction characteristics to power line noise, are carried out by using a combination surge generator standardized in IEC and a network analyzer.The results showed that the proposed panel board is satisfied with the surge immunity level of IEC 61000-4-5, and has an over 20[dB] noise reduction performance in ranges from 150[kHz]∼30[MHz].

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.24 no.8
• /
• pp.860-872
• /
• 2013

In this paper, reasonable and effective building strategies of PPDR network is presented through investigating and analysing current policies for PPDR network of Korea and foreign countries. The research result shows that it is necessary PPDR network is designed and implemented considering currently transient status in aspects of PPDR-related technical roadmaps and existing PPDR networks. Also, in the transient period of more than 5 years, mobile broadband- based private PPDR network should be builded and it should be complemented by some commercial networks such as TRS or other mobile broadband networks.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.927-932
• /
• 2001

It is intended to develope an algorithm for dynamic simulation of fast-acting solenoid valves. The coupled equations of the electric, magnetic, and mechanical systems should be solved simultaneously in a transient nonlinear manner. The transient nonlinear electromagnetic field is analyzed by the Finite Element Method (FEM), which is coupled with nonlinear electronic circuitry. The dynamic movement of the solenoid valve is analyzed at every time step from the force balances acting on the plunger, which include the electromagnetic force calculated from the Finite Element analysis as well as the elastic force by a spring and the hydrodynamic pressure force along the flow passage. Dynamic responses of the solenoid valves predicted by this algorithm agree well with the experimental results including bouncing effects.