• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1149-1151
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• 2002

In this paper, an auxiliary winding driving system of single-phase induction motors is described. Starting charateristics variations are obtained by controlling the auxiliary winding voltage magnitude and phase angle, while the motor's main winding is directly connected to the local utility. A variable auxiliary winding voltage phase angle is shown to yield significant torque control, providing starting and braking torque. The analysis includes the determination of the relationship between the auxiliary winding voltage phase angle and the phase angle difference between the main and auxiliary winding current. The paper proposed for adjusting an auxiliary winding voltage magnitude and phase angle. Experimental results of motor's starting characteristics with using the DC-AMP and PWM inverter for auxiliary winding power supply are shown. The drive is tested using a dynamometer to experimentally verify the results of the theory.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.7
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• pp.22-27
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• 2008

A new excitation strategy for a Switched Reluctance Motor with Auxiliary Winding(SRMAW) is described and tested. The proposed scheme has auxiliary winding with one diode which is wound over all poles in one winding. In this scheme, auxiliary winding is used to reduce magnetic stress during commutations. The abrupt change of a phase excitation produces mechanical stresses resulting in vibration and noise. The acoustic noise is reduced remarkably through the 2-stage commutation. The operational principle and a characteristic comparison of the conventional SRM show that this scheme has some advantages including noise reduction as well as high drive efficiency.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.4
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• pp.175-179
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• 2001

The switched reluctance drive exhibits higher levels of vibration and acoustic noise than that of most competing drives. The main source of vibration in the switched reluctance drive is generated by rapid change of radial force when phase current is extinguished by commutation action. A new excitation strategy for a Switched Reluctance Motor with Auxiliary Winding (SRMAW) is described and tested. This scheme has auxiliary winding with one diode which is sound to all th poles in one winding. In this scheme, auxiliary winding is used to reduce magnetic stress during commutations. The abrupt change of a phase excitation produces mechanical stresses and it results in vibration and noise. The acoustic noise is reduced remarkably through 2-stage commutation. The operational principle and a characteristic comparison to that of the conventional SRM show that this scheme has some advantages including noise reduction as well as high efficiency drive.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.5
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• pp.41-50
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• 1995

Single-phase induction motors are widely used in many light duty applications, especially in home and office. many applications which use these motors require adjustable speed control continuously. In general, the speed control of single-phase induction motor is accomplished at a few discrete speeds by using tapped-windings, pole switching or gear. These techniques are inefficient and complicated. In this paper, Torque controller which adjusts a generating torque using phase difference between main winding voltage and auxiliary winding voltage is proposed. The analysis includes the determination of the relationship between the auxiliary winding voltage is proposed. The analysis includes the determination of the relationship between the auxiliary winding voltage phase angle and torque. Simulation results of the torque-speed characteristics using the controlled auxiliary winding supply are shown and discussed. and the drive is tested experimentally to verify the results of the theory by using a dynamometer.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.763-767
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• 1998

In this paper, we analyzed the characteristics and source of vibration and acoustic noise in SRM drives. The paper study the reduction technique of those by new SRM which has auxiliary field winding. The operating mechanism and vibration and acoustic noise characteristics is examined. This paper suggests the control strategies of auxiliary field winding in order to reduce vibration and acoustic noise.

• Journal of the Semiconductor & Display Technology
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• v.17 no.4
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• pp.56-61
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• 2018

In this paper, a new type of active snubber was proposed to lower the excessive rated voltage of the clamp capacitor which was a problem in the conventional circuit by applying auxiliary winding into the active snubber. A simplified equivalent circuit of the proposed snubber was derived by applying it to QR flyback converter, and the equivalent circuits for each switch state was shown under the steady-state condition. In addition, the maximum voltage of the clamp capacitor as well as the main switch was found by using the steady-state equations. In particular, it was found that the clamp capacitor voltage could be controlled by the auxiliary winding ratio. In order to verify the utility and practicality of the proposed converter with auxiliary winding type active snubber circuit, a prototype with an output voltage of 19V and a maximum load current of 6A was produced and the results were reported.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.11
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• pp.548-556
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• 2003

Switched reluctance motor(SRM) has simple magnetic structure, and needs simple power electronic driving circuit. It is very useful for wide range adjustable speed drive system. But, SRM drive generates large vibration and acoustic noise because it is commutated individually by step pulse m.m.f of each phase. In the vibration and acoustic noise characteristics. the considerable vibration and noise is induced by radial deforming of stator, so the frequency of dominant vibration and noise is coincident with the frequency of natural frequency of mechanical structure. This radial vibration force is generated by abrupt change of radial magnetic force in the phase commutation region. This paper studied about simple electromagnetic structure of SRM using auxiliary compensating winding for the reduction of noise and vibration. This auxiliary winding is coupled with all phase windings electromagnetically and absorb and transfer magnetic energy variation from phase to other phase. By this interaction of phase windings and compensating winding can reduce abrupt radial force change and vibration and acoustic noise. In this paper the improvement effect is examined by the test of prototype machine.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.5
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• pp.350-354
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• 2003

This study proposes a new self-driven active clamp forward converter eliminating the extra drive circuit for the active clamp switch. The converter used the auxiliary winding of the power transformer to drive the active clamp switch and a simple R-C circuit to get the dead time between the two switches. The operation principle was presented and experimental results were used to verify theoretical predictions. A 100-W (5V/20A) prototype converter built that only exhibited 1.5-turn winding number in the auxiliary winding was sufficient to drive the active clamp switch on the input of 50V. Finally, the measured efficiency of the converter was presented and the maximum efficiency of 91% was obtained.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.331-336
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• 2005

With increasing emphasis on non-conventional energy systems and autonomous power generation, development of improved and appropriate generating systems has recently taken on greater significance. This paper describes the performance analysis of a single phase self-excited induction generator (SEIG), suitable for autonomous/standby power systems. The system is also appropriate for wind energy systems and small portable systems. Both windings of the induction machine, the main and the auxiliary, are utilized. One winding will be devoted to the supply excitation current only, by being connected to the excitation capacitor, while the load is connected across the other winding. As the design of excitation, the minimum of self-excited capacitor connected auxiliary winding is determined as the suitable value using a circuit equation of auxiliary winding. For the steady state analysis, the equivalent circuit of the single-phase induction generators is used as a basis for modeling using the double-revolving field theory. The validity of the designed generator system is confirmed by experimental and computed results.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.350-352
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• 1995

The starting characteristics of single phase induction motor(SPIM) is described by control of phase and voltage. Auxiliary winding voltage is controlled by DC amplifier and phase is integrator. These processes enable comparison of torque with slip in each voltage and phase angle variations. Simulation and experimentation results of the motor's torque-slip characteristics using the controlled auxiliary winding voltage and phase angle arc shown and discussed. As a results, starting time is fast and main winding current is small when auxiliary winding voltage is low than rating voltage and starting characteristics is good in phase angle $90^{\circ}$.