• Proceedings of the KIPE Conference
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• 1998.11a
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• pp.18-22
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• 1998

A PWM inverter with an induction motor often has a problem with a high frequency leakage current that flows through stray capacitor between stator windings and a motor frame to ground. This paper presents an equivalent circuit for high frequency leakage currents in PWM inverter feeding an induction motor, which forms an LCR series resonant circuit. A conventional common mode ckoke or reactor in series between the ac terminals of a PWM inverter and those of an ac motor is not effective to reduce the rms and average values of the leakage current, but effective to reduce the peak value. Furthermore, this paper proposes a leakage current damper which is different in damping principle from the conventional common mode choke. It is shown theoretically and experimentally that the leakage current damper is able to reduce the rms value of the leakage current to 25%, where the core used in the leakage current damper is smaller than that of the conventional common-mode choke

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.379-382
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• 2002

GaAs has wide band gap, Therefore that malarial can used high Temperature application. in this paper explain to current-voltage characteristics of thermal effect. we experiment on thermal test of current-voltage characteristics and gate leakage current with real device. As a result, we propose a current-volatage characteristics model. that model base on gate leakage current, and gate leakage current influence gate source voltage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.918-923
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• 1998

Poly-silicon thin film transistors were fabricated on quartz substrates by high temperature processes. Electrical characteristics were measured and compared for 3 transistor structures of Standard Inverted Gate(SIG), Lightly Doped Drain(LDD), and Dual Gate(DG). Leakage currents of DG and LDD TFT's were smaller that od SIG transistor, while ON-current of LDD transistor is much smaller than that of SIG and DG transistors. Temperature dependence of the leakage currents showed that SIG and DG TFT's had thermal generation current at small drian bias and Frenkel-Poole emission current at hight gate and drain biases, respectively. In case of LDD transistor, thermal generation was the dominant mechanism of leakage current at all bias conditions. It was found that the leakage current was closely related to the reduction of the electric field in the drain depletion region.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.828-833
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• 2014

Grid connected transformerless solar power generation system is frequently used with the benefits of cost and efficiency. However, significant DC leakage current can flow from the DC line into the ground with dielectric breakdown in the transformerless solar power generation system. The leakage current occurred in the DC line causes accidents such as fire and electric shock on human. To resolve this problem, high sensitivity DC leakage current sensor is needed. But recently the studies on safety of DC line are not performed. In this paper, a high sensitivity DC leakage current sensor that can detect DC leakage current in solar power generation system, is proposed. Based on the studies, DC leakage current sensor is fabricated and characteristic tests are carried out. Finally, the accuracy of sensor performance is verified by leakage current experiments in solar power generation system.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1069-1071
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• 1995

The electrical properties of Al/TiN/Ti contact are investigated at submicron contacts. The contact resistance and contact leakage current are dependent on metallization, surface dopant concentration, semiconductor surface treatment and contact plug ion implantation. In this paper, the contact resistance and contact leakage current are studied according to surface dopant concentration, semiconductor surface treatment and contact plug ion implantation at 0.8 micron contact. The contact resistance and contact leakage current increases with increasing substrate ion concentration. HF cleaning represents high contact resistance but low contact leakage current while CDE cleaning represents low contact resistance but high contact leakage current. Contact plug ion implantation decreases contact resistance but increases contact leakage current. Specially, RTA represents good electrical properties.

• Journal of Power Electronics
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• v.16 no.3
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• pp.970-981
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• 2016

Leakage currents occur in pulse-width-modulated voltage source inverter (PWM-VSI)-fed permanent magnet synchronous motor (PMSM) drives for air-conditioners, which seriously affect system safety and operation performance. High accuracy modeling and prediction of leakage currents are key issues for the design and implementation of air-conditioning products. In this study, the generation mechanism of leakage currents is discussed. A systematic modeling approach of leakage currents is proposed, including the modeling of leakage current sources and leakage current paths. By using the proposed approach, the complete model of leakage currents in PWM-VSI-fed PMSM drives for air-conditioners has been developed based on the extraction of all parameters. A comparison between the simulated leakage currents based on the developed model and measured leakage currents in the outdoor unit of an air-conditioning product is conducted. The comparison verifies the effectiveness of the proposed modeling approach, and the developed model exhibits high accuracy within a wide frequency range.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.392-396
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• 2004

Experimental equipments for long-term outdoor tests of EHV insulators in outdoor were constructed. The testing insulators have been energized with 89 [kV] phase-to-ground AC voltage under identical condition at station, and the investigation was carried out for leakage current and various environments such as temperature, relative humidity and wind velocity. The test results of leakage current wave trends have forms on distorted waves including harmonics. The porcelain and glass insulators have low leakage current in case of daytime because moisture and humidity have relative low values. In comparison with these conditions, high leakage current was shown at dawn and rainy day due to high humidity. However, leakage current of polymer insulators was shown approximately $129[{\mu}m]$ without relation to the weather due to hydrophobicity on their surface.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.373-376
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• 1999

This paper propose a "common mode voltage damper" that is capable of reducing the common mode voltage produced in the PWM VSI. An push-pull circuits and high frequency leakage current damper[1] are incorporated into the "common mode voltage damper", the design method of which is presented. Effect of "common mode voltage damper" is simulated in this paper verifies the viability and effectiveness in 2.2kW induction motor drive using IGBT inverter. Simulated results show that "common mode voltage damper" makes significant contributions to reducing a high frequency leakage current.ducing a high frequency leakage current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.428-431
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• 2003

In this paper, the stress induced leakage currents of thin silicon oxides is investigated in the ULSI implementation with nano structure transistors. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The transient current was caused by the tunnel charging and discharging of the stress generated traps nearby two interfaces. The stress induced leakage current will affect data retention in electrically erasable programmable read only memories. The oxide current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between $113.4{\AA}$ and $814{\AA}$, which have the gate area 10-3cm2. The stress induced leakage currents will affect data retention and the stress current, transient current is used to estimate to fundamental limitations on oxide thicknesses.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.76-81
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• 2004

This paper presents the results of spectral analysis of leakage current waveforms on contaminated insulators under various fog and environment conditions(salt fog, clean fog, rain) The larger the leakage current during 200ms, the higer the power spectrum at 60Hz. For almost equal maximum current during 200ms, however, the spectrum at 60hz and the odd order harmonics increase emphatically when discharges occur continuously for several half-waves. If contaminated insulators suffers from high salt-density fog, the leakage current occurs with high crest value intermittently, results in the low spectrum. Analysis of leakage current data showed that this electrical activity was characterized by transient arcing behavior contaminants are deposited on the insulator surface during salt fog tests. This provides a path for the leakage current to flow along the surface of the insulator. It is important to have an indication of the pollution accumulation in order to evulate the test performance of a particular insulator. If the drop in surface resistivity is severe enough, then the leakage current may escalate into s service interrupting flashover that degrade power quality.