• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.318-320
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• 2007

Single-phase cycloconverters are widely used for ac-ac power conversion especially for speed control of ac drives. In this paper, a new single-phase to single-phase Z-source cycloconverter topology is proposed. The proposed single-phase Z-source cycloconverter can boost to a desired voltage with various frequency. Thus, it is called a frequency step-down and amplitude voltage step-up converter. The operating principle of the proposed topology is presented. Analysis and simulation for this single-phase Z-source cycloconverter are also presented.

• 전기의세계
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• v.28 no.3
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• pp.51-56
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• 1979

The purpose of this paper is to study the conversion of single phase to three phase. In the proceeding of phase conversion, it is very convinence to convert two-phase from single phase using cycloconverter before and then two to three phase by scott connection transformer. There are also systematized zero-crossing, mono vibrator and ring counter circuit for the gate trigger circuits of cycloconverter. The wave forms of three phase by experimental results are analyzed and discussed the relation of phase difference among them.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.5
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• pp.71-85
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• 1993

The Cycloconverter that the author is going to treat in this paper, has strong advantages over the D.C. Link Inverter in points of chattering torque problem and natural commutation. Thus, the Cycloconverter is expected to be well applied to large and low-speed machines which require better speed control at low frequency. But the control circuit of Cycloconverter has two weak points described as follows. 1) Because of its rather complicated control circuit, it is likely to be illoperating due to unexpected noise signals, thus the higher the accuracy and reliability of the circuit is required to be, the more the circuit may cost. 2) Because the load current is not purely sinusoidal, the Cycloconverter may possibly be destroyed in case of inaccurate convert switching resulted from the difficulties in detecting the load current-zero and the current direction at the moment. In this paper, the author first of all intends to design and build a modified VVVF-type Noncirculating Current Cycloconverter to which recently proposed control methods are applied for improving the circuit simplicity, the control performance, and the system reliability. And then, experiments for observing the output waveforms of the Cycloconverter which is controlled by Singled-Board Computer using 8086 16-bit microprocesser are carried out. Finally the author concludes the result of this study as follows. 1) By replacing the conventional analog control circuits such as Reference Wave Generator, Cosine Timing Wave Generator, and Comparator with softwares, a great circuit simplicity is achieved. 2) The output of the designed Cycloconverter changes its frequency very fast without showing discontinuity of its waveform, and this waveform characteristics enables the smooth speed control of Induction Motor. 3) The design control circuit of Cycloconverter can be applied to the systems of 12 or 24 pulses because of its short processing period.

• 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.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.5
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• pp.352-359
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• 1987

The cycloconverter operating on a circulating current-free mode has many zero crossing points. If an exact zero crossing points are not detected, the three phase-unbalanced currents will flow in a motor. In this paper, the current feedback using a current reference wave is proposed to improve the problems of zero crossing detection, three phase-unbalanced voltages, currents, and torgue ripples. To prevent the saturation of the air gap flux and keep the torque constant, the constant voltage / hertz control with IR compensation is adopted. The PI-controller is designed using the linearized model of the cycloconverterinduction motor system. Alsi, Z-80A single board computer has been used to implement the proposed scheme which results in the performance improvement of cycloconterter-fed induction motor speed control system.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.328-329
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• 2018

본 논문에서는 전기자동차용 단상 온-보드 충전기를 위한 Cycloconverter-type High Frequency Link 회로구조와 능동 전력 디커플링 회로를 이용한 전기자동차용 고전력밀도 양방향 온-보드 충전기를 제안한다. 제안된 시스템은 전력변환부 단계를 줄이기 위한 AC-AC 변환회로와 DC링크 캐패시터를 최대한 줄이기 위해서 벅-타입 능동 전력 필터를 사용한다. 이를 통해 전력변환시스템 전체의 부피를 줄일 수 있으며, 전해 커패시터를 필름 커패시터로 대체하여 수명 문제를 해결할 수 있다. 제안된 시스템의 성능은 MATLAB/Simulink 시뮬레이션을 통해 검증하였다.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.213-214
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• 2018

본 논문에서는 전기자동차 온-보드 충전기용 단상 cycloconverter-type high frequency link 컨버터의 전력 제어성능과 동적 응답특성을 개선하기 위하여 예측전류제어 기법을 적용한다. 배터리를 충전 및 방전하기 위하여 전력계통에 연결되는 V2G 충전기는 전압 변동, 고조파 왜곡 등의 외란 발생에도 강인한 동적 응답 특성을 유지하여야 한다. 예측전류제어 기법이 적용된 제어기는 계통 외란이 존재하는 경우에도 전력 레퍼런스를 빠르게 추적하고 정확한 듀티를 생성할 수 있으므로 우수한 동적 및 과도 응답특성을 갖는다. 제안하는 제어기의 성능과 파라미터 변동에 대한 민감도는 PSIM 시뮬레이션을 이용하여 평가되며, 여러 계통외란 상태에서 PI 제어기와 비교된다.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.369-370
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• 2020

본 논문에서는 전기자동차용 양방향 배터리 충전장치에 사용되는 CHFL(Cycloconverter-type High Frequency Link) 컨버터에서 발생하는 고전압 스파이크 저감을 위한 스위칭 방법을 제안한다. CHFL 컨버터는 양극성 고주파 파형 정류시 LC 필터의 인덕터와 변압기의 누설 인덕터에 저장된 에너지로 인해 고전압 스파이크가 발생하게 된다. 제안된 스위칭 방법은 환류 구간을 통해 저장된 에너지를 회생시킴으로서 고전압 스파이크 문제를 해결할 수 있다. 제안된 스위칭 방법의 성능은 MATLAB/ Simulink 시뮬레이션을 통해 검증하였다.