• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.2
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• pp.125-134
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• 1992

This paper presents a cycloconverter with an LC resonant circuit for an induction motor drive. The cycloconverter can keep input displacement factor at 1.0 by independently controlling real and reactive power under any load conditions. Furthermore it can keep power factor at about 1.0 since input and output current waveforms are nearly sinusoidal. Since it uses high frequency resonant circuit for commutation source, it can produce an output voltage of hundreds of hertz. Since it is also possible to make a system of high capacity using the cycloconverter, it is appropriate to drive motors with high speed and high capacity as well as general purpose motors, In this paper, we describe the operating principles of the cycloconverter and power control algorithms, and analyze its waveforms and present its characteristics. Expermental results are shown for the volts/hertz control of the induction motor and the validity of the proposed model is verified.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.800-802
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• 1993

This paper presents a new current control method of the six-pulse cycloconverter for a variable speed drive system of a large capacity ac mortor. It is necessary for a high performance control as a vector control that the output current scheme of the cycloconverter has a good charistic in transient state. A new proposed current control method is that the output current of the cycloconverter is followed after the current reference directly as fast as possible under any condition. Simulation resualts with the proposed new current control method are shown. As a result the validity of the proposed method is confirmed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.45-50
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• 1998

In recent year, inverters and cycloconverters system are widely used for fed induction motor drives. Motor drives by cycloconverter is possible to frequency have been directly changed without AC/DC converter, so that circuits is simpler than inverter. A aims of this paper is the control strategy and hardware design for vector control system by cycloconverter fed induction motor drives. In this paper, Algorithm of vector control is derivlid from the model of controlled current source-fed induction motor. Vector control system is implemented using these algorithm and a pulse width controled cycloconverter using a SCR. Cycloconverter of vector control system is controlled by pulse width of SCR's trigger signal. pulse width is controlled primary command current $li_1l$ and frequency TEX>$\omega_1$..

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.121-126
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• 2013

Cycloconverter used as a power conversion device in the speed and torque control system of AC machines has the advantage of a simple control and a large torque at low speed. In addition, because a rectifier, a DC link, and an inverter are not installed, this system is simple and suitable for large power system. If a power conversion device, which is currently used as a propulsion motor of large vessel, is changed into cycloconverter, the system is simplified and then the installation costs can be significantly reduced. However, conventional cycloconverter has the increased harmonics because the power loss is large and the waveform of output voltage is distorted, due to the high-speed switching of power semiconductor devices. In order to improve these shortcomings, this paper describes a phase shifting filter which is composed of two inputs with different phases in the primary side and one output in the secondary one. As the voltage waveforms with two different phases are added and transformed into the secondary side, these outputs are close to sinusoidal waves. Thereby the voltage waveforms, which are applied to the propulsion motors, are improved and total harmonic distortions (THDs) are significantly reduced.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.573-578
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• 1991

This paper presents a study on the cycloconverter with a LC resonant circuit for a induction motor drive which keeps the Input displacement factor at 1.0 by controlling real and reactive power independently under any load conditions. The input and the output current waveforms are sinusoid, and consequently Input power factor is nealy 1.0. In this paper, the operating principles of this cycloconverter, the control algorithms, the waveform analyses, and the characteristics of the system are described. The volts/hertz control of the induction motor is experimented, and the reasonability of this proposal is verified.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.403-405
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• 1994

The dynamic behavior of circulating current cycloconverter and flywheel energy storage unit is the subject of this investigation. The system of this type can control of real and reactive power flow between flywheel-cycloconverter and power three phase network. In this paper, waveform level simulation indicates that power flow control of is possible and this system can be used to varible application.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1002-1004
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• 1992

This paper presents a study of the partial circulating current type cycloconverter with a resonant circuit for induction heating. A method of input power factor improvement is proposed. Since the circulating currents flow through the circulating current reactors, the out-put currents are continuous and sinusoid. The proposed cycloconverter can keep the displacement factor at 1.0 by PWM control method regardless of load. The control functions are derived, the operational principles are described and the simulation and experimental results are presented.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.185-192
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• 1998

This paper presentsa new currnet control method ofthe six-pulse cycloconverter which is used as a variable speed drive system of a large capacity ac mortor. For a high performance control as a vector control, it is necessary that the output current control ofthe power converter has a good characteristic in transient state. A new proposed current control method is that the output current of a cycloconverter is followed after the current reference directly as fast as possible under any condition. Simultion results for the proposed new current control method are shown and its validity of the proposed method is confired.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.9
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• pp.1239-1246
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• 1995

A forced commutated cycloconverter (FCC) is a direct ac-ac converter capable of providing simultaneous voltage and frequency transformations. In this paper, vector control of an induction motor controlling stator current with forced commutated cycloconverter is presented. The advantage of current control is that the stator dynamics are eliminated and high performance vector control can be achieved. A novel modulation method based on dq transformation techniques is presented. Proposed modulation strategy generates the low frequency modulation function by the instantaneous value of the desired output voltages not by the steady state values of output magnitude and output frequency. PI control and predictive control algorithm for current control are applied, and the validity of proposed method is confirmed through digital simulations. Simulation results of step response and torque distubance and current control are presented.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.332-333
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• 2019

본 논문에서는 전기자동차용 단상 양방향 온보드 충전기를 위한 Cycloconverter-type high frequency link 컨버터에 Si-IGBT와 SiC-FET을 적용하여 전력반도체의 전력 손실을 예측하고 비교하고 분석한다. 와이드밴드갭 전력반도체 중 하나인 SiC-FET은 기존 Si기반의 IGBT를 대신하여 사용될 전력반도체로써 각광 받고 있다. 또한, 낮은 온-저항으로 인해 적은 전력손실과 고주파 스위칭을 통한 직류단 필터의 크기감소를 통해 높은 전력밀도를 달성할 수 있다. 이에 Si-IGBT와 SiC-FET을 Cycloconverter-type high frequency link 컨버터에 적용하여 전력손실을 PSIM thermal module을 통해 시뮬레이션하고 비교 분석한다.