• Journal of Power Electronics
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• v.13 no.3
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• pp.329-338
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• 2013

In this paper, the charging characteristics of series resonant type high voltage capacitor chargers considering the transformer stray capacitance have been studied. The principles of operation for the four operational modes and the mode changes for the four different switching frequency sections are explained and analyzed in the range of switching frequency below the resonant frequency. It is confirmed that the average charging currents derived from the above analysis results have non-linear characteristics in each of the four modes. The resonant current, resonant voltage, charging current, and charging time of this capacitor charger as variations of the switching frequency, series parallel capacitance ratio ($k=C_p/C_s$), and output voltage are calculated. From the calculation results, the advantages and disadvantages arising from the parallel connection of this stray capacitance are described. Some methods to minimize charging time of this capacitor charger are suggested. In addition, the results of a comparative test using two transformers whose stray capacitances are different are described. A 1.8 kJ/s prototype capacitor charger is assembled with a TI28335 DSP controller and a 40 kJ, 7 kV capacitor. The analysis results are verified by the experiment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1877-1879
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• 2012

Generally, stray capacitance is unnecessary element of designing circuit, because it can not be predicted by a designer. But we propose LC Resonant Circuit using stray capacitance of transformer. This method proposes miniaturization of circuit, because LC Resonant Circuit can be make simply to using stray capacitance instead of capacitor and size of transformer is reduced. Finally, we research aspect of dielectric heating by change of frequency and output voltage using developed converter.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.3
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• pp.302-307
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• 1988

A noble interconnection line capacitance measurement method to be able to remove the measurement errors from the probe pad to substrate stray capacitance has been proposed and verified. The measurement errors in the capacitance measurement, which usually be involved from the probe pad to substrate stray capacitance, can easily be removed by isolating the metal probe pad from the substrate with a grounded shield plate between the probe pad the substrate. The measurement results by using this improved capacitance measurement method were compared with the calculations by two-dimensional computer simulations.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1122-1132
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• 2019

In this paper, aiming at high-voltage applications, transformer windings schemes of multiple-output two-transistor flyback converters are investigated, which are mainly based on the stray capacitances effect. First, based on a transformer model including equivalent stray capacitors, the operational principle of the converter is presented, and the main influence of its stay capacitors is determined. Second, the windings structures of the transformer are analyzed and designed based on the stray capacitances effect. Third, the windings arrangements of the transformer are analyzed and designed through a coupling analysis of the secondary windings and a stray capacitance analysis between the primary and secondary windings. Finally, the analysis and design conclusions are verified by experimental results obtained from a 60W laboratory prototype of a multiple-output two-transistor flyback converter.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1206-1213
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• 1994

This paper presents the operation principle and design rule of the Rogowski coil which can measure the transient current and describes the calibration and application experimental results for performance evaluation. It is obtained that the response curves of the Robowski coil with the turns of 300 and the passive integrator to sinusoidal input give a good linearity up to the frequency of 500 [kHz] and the current measurement system gaving the Rogowski coil is the frequency bandwidth of 40 [Hz]~700 [kHz]. As an application experiment for the fabricated modeling power transmission line, the impulse current, which limitates the direct lightning return stroke to overhead ground wire, is measured by the Rogowski coil and its fast Fourier transformation is carried out. The equivalent circuit of the Rogowski coil considering the stray capacitances is proposed, and the theoretical analysis is in good agreement with the measurement results. Also, it is found that for high frequency domain the stray capacitance such as a distributed capacitance to the shield and the capacitance between windings of coil should be considered in designing the Rogowski coils since the resonance originates from the stray capacitance and the self-inductance of the Rogowski coil.

• Journal of Power Electronics
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• v.10 no.2
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• pp.107-114
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• 2010

This paper presents the operational characteristics of a high voltage flyback converter with resonant elements. In high voltage low power applications, the effect of a transformer’s stray capacitance might be the most important factor that influences the overall performance of the circuit. A detailed mode analysis and the design procedure are presented in designing the high voltage flyback converter. To verify and confirm the validities of the presented analysis and design procedure, a computer simulation and experiments have been performed.

• Journal of IKEEE
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• v.18 no.1
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• pp.31-36
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• 2014

In this paper, self-resonant characteristics of transformers were analyzed in accordance with changes of characteristics regarding to the stray capacitance, the volume of winding and the winding ratio were organized by formulas. Generally, the stray capacitance is considered as an unnecessary factor in processing transformers design as well as one of the inherent characteristics. In particular, these characteristics can be appeared clearly in the high frequency driving and Electrical resonance occurs in transformer, according to coupling with a magnetic factor at a particular frequency. In the case of high-voltage output applications, such as medical equipments, It is required to output high-voltage gain. Therefor, If Self-Resonant Characteristic is applied to High-Voltage transformer design, Not only the transformer and circuit but also related the system size can be reduced. So we propose it as one of additional high voltage transformer design methods.

• Transactions on Electrical and Electronic Materials
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• v.2 no.1
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• pp.16-21
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• 2001

A new technique to measure low level capacitance variations of a gyroscope is proposed. It is based on the improved CVC(capacitance to voltage converter) biased by a d.c. current source and the peak detector without any low pass filter. This setup of the measurement system makes it possible to provide higher speed of measurement and wide operation range. The d,c, drift of the conventional CVC and stray capacitances are automatically compensated. Key parameters that affect the performance of the measurement system are illustrated and computer simulation results are presented. The demonstrated measurement system for micromachined gyroscope applications shows a linearity of 0.99972 and a resolution of 0.67fF from 10 fF to 120 fF at 10 kHz.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.13-16
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• 1990

코로나 예비전리를 이용한 KrF 레이저의 장펄스화를 위해 동축형 4단 펄스정형회로 (PFN)를 구성해서 용량이행형의 회로에 인덕턴스가 부가된 방식의 전류, 전압을 비교하여 PFN을 동축형으로 제작함으로 인한 Stray Capacitance (Cs)의 존재로 인해 좋은 효율의 장펄스화를 이루어짐을 밝혔다. 구성된 PFN을 절연유에 넣어 충전전압 15kV, N2 55Torr에서 330ns 펄스폭의 전류파형을 측정했다.

• Journal of Power Electronics
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• v.17 no.1
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• pp.305-313
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• 2017

A novel interference isolation method is proposed by using several designed coils in capacitive power transfer systems as isolation impedances. For each designed coil, its stray parameters such as the inter-turn capacitance, coil resistance and capacitance between the coil and the core, etc. are taken into account. An equivalent circuit model of the designed coil is established. According to this equivalent circuit, the impedance characteristic of the coil is calculated. In addition, the maximum impedance point and the corresponding excitation frequency of the coil are obtained. Based on this analysis, six designed coils are adopted to isolate the interference from power delivery. The proposed method is verified through experiments with a power carrier frequency of 1MHz and a data carrier frequency of 8.7MHz. The power and data are transferred parrallelly with a data carrier attenuation lower than -5dB and a power attenuation on the sensing resistor higher than -45dB.