• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1356-1361
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• 2008

A switched reluctance generator(SRG) has simple magnetic structure, and needs simple power electronic driving circuit. But, a SRG are no windings or permanent magnets on the rotor, and there are concentrated windings placed around each salient pole on the stator. Because of the characteristics of time-sharing excitation, the control of SRG is very flexible. And there are several parameters for controlling SRG, such as switch turn-on angle, switch turn-off angle, and exciting voltage and controlling mode, all these will affect the generation greatly. A SRG has positive torque at increasing inductance region and negative torque at decreasing inductance region. In this paper, we studied characteristics about the switch turn-on and off angles according to switch method for constant output voltage of the fixed speed SRG. It is the acoustic noise and torque ripple characteristics. Characteristics for a switch angle and method are presented by experiment using a 50W SRG with 12/8 poles.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.4
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• pp.334-341
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• 2011

This paper presents a design and implementation of DC/DC converter with very wide input voltage ranges for EPBS whose input voltage is from 30V to 400V and output voltage is 48V. This converter is comprised of two stages that one is for control and the other is for only galvanic isolation. The proposed converter uses the hard-switched buck-boost topology for control purpose and soft-switched LLC resonant converter for isolation. The proposed converter has been verified with 300W design.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.1
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• pp.15-24
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• 2012

In this paper, we suggest the dynamic-response-free SMPS using a new high-resolution DPWM generator based on switched-capacitor delay technique. In the proposed system, duty ratio of DPWM is controlled by voltage slope of an internal capacitor using switched-capacitor delay technique. In the proposed circuit, it is possible to track output voltage by controlling current of the internal capacitor of the DPWM generator through comparison between the feedback voltage and the reference voltage. Therefore the proposed circuit is not restricted by the dynamic-response characteristic which is a problem in the existing SMPS using the closed-loop control method. In addition, it has great advantage that ringing phenomenon due to overshoot/undershoot does not appear on output voltage. The proposed circuit can operate at switching frequencies of 1MHz~10MHz using internal operating frequency of 100 MHz. The maximum current of the core circuit is 2.7 mA and the total current of the entire circuit including output buffer is 15 mA at the switching frequency of 10 MHz. The proposed circuit has DPWM duty ratio resolution of 0.125 %. It can accommodate load current up to 1 A. The maximum ripple of output voltage is 8 mV. To verify operation of the proposed circuit, we carried out simulation with Dongbu Hitek BCD $0.35{\mu}m$ technology parameter.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.169-171
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• 1994

This paper suggests a SRM control scheme driven by a variable voltage source. This scheme shows that it is unnecessary to introduce a switch to control dc-link voltage and to limit a phase current. And its vary easy to build-up flat-topped phase current which is advantageous to the high torque and efficiency drive of a SRM. Experimental tests are shown to verify this suggestion.

• The Transactions of the Korean Institute of Power Electronics
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• v.2 no.2
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• pp.49-56
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• 1997

Switched Reluctance Motors(SRMs) have a considerable inherent torque ripple due to the driving characteristics of pulse current waveform and the nonlinear variation inductance profile. This paper describes a current shape characteristics to effect a torque ripple reduction, and one pulse mode switching control method is proposed to minimize torque ripple of a switched reluctance motor regardless of speed and load condition by regulating tow parameters, such as, advance angle and exciting voltage. The experiments are performed to verify the capability of proposed switching method on 6/4 salient type SRM.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.19-22
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• 2001

A Switched Reluctance Generator attracts much attention in the generator because of high efficiency, simplicity, and ruggedness. However, they require rotor position information to operate. In many systems, the rotor position sensor is expensive, limited and undesirable. This paper describes a new approach to estimating the rotor position of the SRG from the measured terminal voltage and current for rotor position sensorless control. The proposed method is based on the instantaneous flux of the SRG. The proposed technique is very simple. The proposed method is verified by computer simulation and experiments.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.370-376
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• 1993

In this paper, we present the voltage source algorithm for high speed and low torque ripple operation of a switched reluctance motor (SRM). The SRM has simpler structure than the traditional dc or ac motor. It has a high starting torque and can be operated in the wide range of speed. So it can be applied to various areas. But the SRM has some difficulties in driving circuit and controller due to the large inductance variations. In this study, in order to produce the low torque ripple and the high speed operation, a voltage source algorithm is proposed. We showed the good performance of the proposed controller through simulation and experiment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.523-525
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• 2004

This paper describes a new method of detecting rotor position in switched reluctance motor(SRM). Some strategies of position sensorless control methods for the motor include the measurement of phase current and applied pulse voltage in an unexcited phase. The principle of the estimation of a rotor position is based on the detection of inductance by pulse currents. Suggested method is verified by some experimental tests.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.850-852
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• 1993

A buck-boost zero current switched(ZCS) series resonant AC to DC converter for the DC output voltage regulation together with high power factor is proposed. A dynamic model for this AC to DC converter is developed and an analysis for the internal operational characteristics is explored. With the proposed control technique, the unity power factor and the DC output voltage regulation without a current overshoot can be obtained.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.3
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• pp.265-272
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• 2001

The traditional 60[Hz] power supply for during magnetron in microwave oven has disadvantages of heavy weight and low efficiency due to 60[Hz] High Voltage Transformer(HVT), capacitor and th phase control of thyristors. To alleviate these disadvantages, this paper proposes a 20[kHz] phase-shifted Full-Bridge(FB) Zero-Voltage-Switched(ZVS) PWM converter for driving a 600[W] magnetron in an 1[kW] microwave oven. The proposed converter has advantages of light weight and high power density.