• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.127-135
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• 2014

In this paper a novel converter structure based on cascade converter family is presented. The suggested multilevel advanced cascade converter has benefits such as reduction in number of switches and power losses. Comparison depict that proposed topology has the least number of IGBTs among all multilevel cascade type converters which have been introduced recently. This characteristic causes low cost and small installation area for suggested converter. The number of on state switches in current path is less than conventional topologies and so the output voltage drop and power losses are decreased. Symmetric and asymmetric modes are analyzed and compared with conventional multilevel cascade converter. Simulation and experimental results are presented to illustrate validity, good performance and effectiveness of the proposed configuration. The suggested converter can be applied in medium/high voltage and PV applications.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 추계학술대회
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• pp.192-193
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• 2010

본 논문에서는 Quasi Z-source AC/AC converter를 cascade로 연결한 시스템의 출력 전압 특성을 고찰 한다. 제안된 시스템은 Quasi Z-source AC/AC converter의 buck-boost와 boost의 출력특성을 기본으로 하고 있으며, 각각 출력 단이 절연된 단상 Quasi Z-source AC/AC converter 2대가 cascade로 연결된 구조이다. 제안된 시스템의 응용으로는 고전압 대용량의 교류전원 시스템과 고정 주파수의 가변전압과 같은 분야이다. 본 논문에서는 제안된 시스템에 대하여 PSIM 시뮬레이션을 통하여 출력 특성을 고찰하였다.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.298-304
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• 2014

In this paper, a novel topology for cascade multilevel converter is introduced, which has many levels with fewer number of power electronic components. Less number of the switches leads to the reduction of size, losses, simple control strategy and high efficiency. For proposed multilevel converter, a new algorithm for determination of dc voltage source values has been recommended. The performance and operation of the proposed multilevel converter has been evaluated with the simulation results of a cascade 25-level converter.

• 전력전자학회논문지
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• 제22권2호
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• pp.118-125
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• 2017

In this paper, we propose a smart transformer for a smart transformer miniature model, which can replace a 60 [Hz] single-phase transformer installed in an electric vehicle. The proposed smart transformer is lighter than a conventional transformer, can control instantaneous voltage, and can be expected to improve power quality through harmonic compensation. The proposed intelligent transformer consists of an incoming part, an AC/DC converter, and a dual active bridge. Only the incoming part and the AC/DC converter are described in this paper. The proposed intelligent transformer has 75 kVA 3.3 kV input and 750 V DC output, which are verified by simulation and experiment.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.366-370
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• 2003

This paper introduces a new design and fabrication technology of 28 GHz low-cost up and down converter modules for digital microwave radios, The design of the converter module is based on unit circuit blocks, which are to be characterized using a special test fixture. Based on the cascade analysis of the module the 28 GHz up and down converter modules have been designed and implemented. The measured module performance agrees with the cascade analysis. New components such as a tapped edge-coupled filter and a new Ka-band waveguide-to-microstrip transition, which are less sensitive to fabrication tolerances, have been used in the module implementation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.815-818
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• 2004

The emerging applications such as reliable back-up power system and renewable energy call for high boost U-n converter. The conventional topologies to get high output voltage are using flyback circuit, cascade converters, and coupled inductor DC-DC converter. They have the stress and loss related to the leakage energy which results in low efficiency Tn this paper, novel high boost converter is presented. It has a structure of cascade boost converter but only one switch. Therefore, drive circuit is simple and extreme duty ratio is eliminated. To verify the proposed circuit, theoretical analysis and experimental results has been done using a prototype power supply.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1866-1868
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• 1998

This paper propose zero voltage and zero current switching buck converter using a single switch. This converter is electrically equivalent to two basic buck converter in a cascade. Proposed converter is switching at high frequency and operate in high efficiency at wide load range due to resonant switching.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.395-399
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• 2001

In this paper, various reduced parts converter topologies and control strategies for power factor correction and motor control are reviewed and systematic design methodology is developed. From this investigation, the converter topologies could be mainly categorized into cascade type and unified type. The detailed operational principles are examined and the performance comparison is derived to illustrate merits and limitations of the converters. Simulation results are provided to help the better understanding of the theoretical description and several experimental results are presented on prototype induction motor better brush less dc (BLDC) motor drives, along with cascade and unified type converters.

• 한국정보전자통신기술학회논문지
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• 제10권6호
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• pp.529-534
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• 2017

본 논문에서는 스마트그리드의 핵심 설비 중 하나인 반도체 응용 고주파 변압의 개발을 위한 PWM 컨버터의 PWM 생성 방식과 그 구현에 관한 논문으로, H-bridge의 cascade 방식으로 구성된 PWM 컨버터의 경우 각 H-bridge간의 전압 balancing이 항상 이슈로 대두되는 바, 이러한 불균형은 대부분의 경우 각 H-bridge에 부가되는 스위칭 부하가 각각 균형적으로 분포되는 것이 불가능하기 때문에 발생하는 것으로 이를 해결하기 위해 종래의 경우 스위칭 패턴에 복잡한 리던던시를 추가하여 해결 하였으나, 본 논문에서 적용하는 방법은 이러한 리던던시가 불필요해 제어기의 부담을 저감할 수 있다. 본 논문에서는 이러한 자동부하분담 PWM 방식(ALB-PWM)의 실 구현에 관하여 논하였다.

• Journal of Power Electronics
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• 제13권3호
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• pp.419-428
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• 2013

The modular multilevel cascade converter (MMCC) is a new family of multilevel power converters with modular realization and a cascaded pattern for submodules. The MMCC family can be classified by basic configurations and submodule types. One member of this family, the Hexverter, is configured as Double-Delta Full-Bridge (DDFB). It is a novel multilevel AC/AC converter with direct power conversion and comparatively fewer required components. It is appropriate for connecting two three-phase systems with different frequencies and driving an AC motor directly from a utility grid. This paper presents the dq model of a Hexverter with both of its AC systems by state-space representation, which then simplifies the continuous time-varying model into a periodic discrete time-invariant one. Then a generalized multivariable optimal control strategy for regulating the Hexverter's independent currents is developed. The resulting control structure can be adapted to other MMCCs and is flexible enough to include other control criterion while guaranteeing the original controller performance. The modeling method and control design are verified by simulation results.