Proceedings of the KIPE Conference (전력전자학회:학술대회논문집)

The Korean Institute of Power Electronics (전력전자학회)
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A Simple Control Strategy for Balancing the DC-link Voltage of Neutral-Point-Clamped Inverters at low modulation index

Neutral-Point-Clamped 인버터의 저 변조지수에서 DC 링크 전압 균형을 위한 간단한 컨트롤 기법

  • Ma C.S. (Dept. of Electrical Hanyang University) ;
  • Kim T.J. (Dept. of Electrical Hanyang University) ;
  • Kang D.W. (Dept. of Electrical Hanyang University) ;
  • Hyun D.S. (Dept. of Electrical Hanyang University)
  • 마창수 (한양대학교 전기공학과) ;
  • 김태진 (한양대학교 전기공학과) ;
  • 강대욱 (한양대학교 전기공학과) ;
  • 현동석 (한양대학교 전기공학과)
  • Published : 2003.07.01
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Abstract

This paper proposes a simple control strategy based on the discontinuous PWM(DPWM) to balance the DC-link voltage of three-level Neutral-Point-Clamped(WPC) inverters at low modulation index. New DPWM methods in multi-level inverter are also introduced. The proposed DPWM method changes the path and duration to flow the neutral point current out of or into neutral point of the DC-link and it makes the overall fluctuation of the DC-link voltage zero during a sampling time of reference voltage vector. Therefore, the voltage of the DC-link can be balanced fairly well and also the voltage ripple of the DC-link is reduced significantly. Moreover, comparing with conventional methods, the proposed strategy is very simple. The validity of the proposed DPWM method is verified by experiment

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