• Journal of Power Electronics
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• v.2 no.2
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• pp.88-94
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• 2002

The demand for protection of power electronic application has during the last couple of vears increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight inductance over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection of adding inductance of existing High-speed and new Typower Fuse protection. First, the problem of adding inductance of exiting High-speed and new Typower Fuse DC-link circuit is treated, second a short discussion of protection of the IGBT module is done, and finally, the impect of the high frwquency loading on the currying capability of the fuses is presented.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.703-707
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• 2001

The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight increase the over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection. First, the problem of adding inductance of existing High-Speed and new Typower fuses in DC-link circuit is treated, second a short discussion of the protection of the IGBT module is done, and finally, the impact of the high frequency loading on the current carrying capability of the fuses is presented.

• Journal of Power Electronics
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• v.13 no.3
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• pp.349-361
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• 2013

As a result of the advantages such as high efficiency, continuous current and high stability margin, push-pull converter with continuous current (PPCWCC) is competitive for battery discharge regulator (BDR) which plays an important role in power conditioning unit (PCU). Leakage inductance yields current spike in low-ripple current of PPCWCCs. The operating modes are added due to leakage inductance. Therefore the steady state performance is affected, which is embodied in the spike of low-ripple current. PPCWCCs which are suitable for BDR can be separated into three types by current spike characteristics. Three representative topologies IIs1, IIcb2 and Is3 are analyzed in order to investigate the factors on the magnitude and duration of spike. Equivalent current sampling method (ECSM) which eliminates the sampling time delay and achieves excellent dynamic performance is adopted to prevent the spike disturbance on current sampling. However, ECSM reduces the sampling accuracy and telemetry accuracy due to neglecting the spike. In this paper, ECSM used in PPCWCCs is summarized. The current sampling error is analyzed in quality and quantity, which provides the foundation for offsetting and enhancing the telemetry accuracy. Finally, current sampling error rate of three topologies is compared by experiment results, which verify the theoretical analysis.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.693-696
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• 2011

The SRM (Switched Reluctance Motor) is composed of silicon steel plates where the rotor structure is simple and laminated without coil winding or permanent magnet, making it mechanically robust and its maintenance and repair excellent. Applying SRM as traction motor for railway vehicle is given consideration because of its ruggedness capability in severe loading condition and its compact structure. Optimal design of SRM is needed to reduce torque ripple to apply SRM for railway traction drive because SRM has high torque ripple. In this paper, switched reluctance motor with three different stator pole shapes is taken for magnetic analysis using 3d finite element method to apply SRM as traction drive for railway vehicle. It is observed that the model 3 added Tooth Tang Depth and Slot Round to stator shape gives the improved inductance and torque characteristic.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.80-82
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• 2004

The single phase switched reluctance motor(SRM) is more simpler and robust in the structure than poly phase SRM. It has the merits that it reduces the switching elements and the energy density per volume is very high. Recently, it has been researched and developed in various types and starting method due to the technique of power electronics and the computer added design. This paper presents a analytical representation of the phase inductance of a single phase SRM, as function of position and current, taking into account the non-linearity of the magnetic circuit. the method is based on Fourier series expansion. Analytical expressions for the calculation of instantaneous phase inductance, flux linkage, coenergy and electromagnetic torque as a function of rotor position and winding currents are derived.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.188-189
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• 2010

This paper proposed a new zero-voltage switching(ZVS) Two-Inductor boost converter. The conventional Two-Inductor boost converter has defect. When the switch is turned off, the high voltage spike is occurred in the switch by leakage inductance and switch parasitic capacitor. To solve this problem, the parallel resonant capacitor is added to the conventional Two-Inductor boost converter. Using quasi-resonant between parallel resonant capacitance and leakage inductance, the switches is operated soft switching. A reduction of transformer turn ratio is achieved by the voltage doubler rectifier.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.873-879
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• 2007

We have implemented a highly efficient 2.14-GHz class-F amplifier using Freescale 4-W peak envelope power(PEP) RF Si lateral diffusion metal-oxide-semiconductor field effect transistor(LDMOSFET). Because the control of the all harmonic contents is very difficult, we have managed only the $2^{nd}\;and\;3^{rd}$ harmonics to obtain the high efficiency with simple harmonic control circuit. In order to design the harmonic control circuit accurately, we extracted the bonding wire inductance and drain-source capacitance which are dominant parasitic and package effect components of the device. And then, we have fabricated the class-F amplifier. The measured drain and power-added efficiency are 65.1 % and 60,3 %, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.265-272
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• 2007

In this paper, a frequency changeable antenna using dual half wavelength loaded line structure is proposed for multiband mobile handset applications. The proposed antenna has a capability of independent frequency shift by controlling two added inductance values in two different bands. Experimental results indicate that the proposed antenna provides enough effective bandwidth to cover $CELLULAR(824\sim894\;MHz)$, $EGSM(880\sim960\;MHz)$, $DCS1800(1,710\sim1,880\;MHz)$, $PCS1900(1,850\sim1,990\;MHz)$ and $WCDMA(1,920\sim2,170\;MHz)$ bands and peak gain variation is only 0.54 dB.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.588-590
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• 1994

This paper describes current controlled PWM technique of IPM synchronous motors for a wide variety of speed control applications. The IPM synchronous motors have a saliency, in which the q-axis inductance is larger than the d-axis inductance. As a consequence, there exists a reluctance torque component Thus when this component is added to the torque component produced by the stator currents and the air-gap flux, IPM motor drives are readily applicable where full torque Is required up to full or base speed. 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 IPMSM 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 wide variety of speed control strategy is analyzed and the performance is investigated by the computer simulation using actual parameters of a drive system. Simulation results are given and discussed.

• Journal of the Korean Ceramic Society
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• v.28 no.9
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• pp.675-682
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• 1991

Among many problems that need to be solved in the process of preparing multilayer chip LC filters, we studied the control of shrinkage in order to prevent the crack, warpage, and/or delamination which occurs at the interface between the inductance (L part) and the capacitance (C part). Shrinkage was controlled by compositions, powder size, calcining temperature and amount of organic binder. Capacitance sheet was prepared by mixing 65 wt% binder with the composition of 96 wt% TiO2 having an average particle size of 0.5 $\mu\textrm{m}$, 3 wt% CuO. After small amount of MnO2 and SiO2 added, it was calcined at 750$^{\circ}C$ for 2 hr. Inductance sheet was prepared by mixing 60 wt% binder with the composition of 49.5% mol% Fe2O3, 20.5 mol% ZnO, 20 mol% NiO and 10 mol% CuO which was calcined at 775$^{\circ}C$ for 2 hr. These sheets was laminated at 250 kg/$\textrm{cm}^2$, and cofired at 900$^{\circ}C$ for 2 hr to give rise to a multilayer chip LC filter without any warpage.