Balancing and harmonic analysis of flying capacitor multilevel converters

To supply medium-voltage AC machines, DC-AC converters working with a high bus voltage are required. By using multilevel converters, these high voltages can be supplied without the need for switches with a high voltage rating. Moreover, the output voltage waveform can be improved considerably. The flying capacitor multilevel converter is a recently developed converter topology assuring a flexible control and modular design. However, the flying capacitor multilevel converter requires a balanced DC voltage distribution. This can be realized by using a special control leading to natural balancing or by measuring the voltages and selecting the appropriate switching state. The balancing is influenced by three factors, namely the harmonic content of the reference waveform, the switching frequency and the load impedance. In addition to the voltage balancing of the flying capacitor multilevel converter, the output voltage must ensure the control of the load, e.g. a three phase AC machine.

[1]  T.A. Meynard,et al.  Natural Balance of Multicell Converters: The Two-Cell Case , 2006, IEEE Transactions on Power Electronics.

[2]  S. Bernet,et al.  Design and comparison of 4.16 kV neutral point clamped, flying capacitor and series connected H-bridge multi-level converters , 2005, Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005..

[3]  Ivo Barbi,et al.  Self-balancing of the clamping-capacitor-voltages in the multilevel capacitor-clamping-inverter under sub-harmonic PWM modulation , 2001 .

[4]  Hd.T. Mouton,et al.  Natural balancing of series-stacked power quality conditioners , 2003 .

[5]  G. Clos,et al.  Simple direct capacitor voltage balancing of a flying capacitor converter , 2005, 2005 European Conference on Power Electronics and Applications.

[6]  D.G. Holmes,et al.  Analytical Modelling of Voltage Balance Dynamics for a Flying Capacitor Multilevel Converter , 2007, 2007 IEEE Power Electronics Specialists Conference.

[7]  J.A. Melkebeek,et al.  Fully equipped half bridge building block for fast prototyping of switching power converters , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[8]  Fang Zheng Peng,et al.  Multilevel converters-a new breed of power converters , 1995, IAS '95. Conference Record of the 1995 IEEE Industry Applications Conference Thirtieth IAS Annual Meeting.

[9]  T.A. Meynard,et al.  Natural Balance of Multicell Converters: The General Case , 2006, IEEE Transactions on Power Electronics.

[10]  M. Margaliot,et al.  Simple analysis of a flying capacitor converter voltage balance dynamics for DC modulation , 2008, 2008 13th International Power Electronics and Motion Control Conference.

[11]  Fang Zheng Peng,et al.  Multilevel inverters: a survey of topologies, controls, and applications , 2002, IEEE Trans. Ind. Electron..

[12]  Hendrik Du Toit Mouton.  Analysis and synthesis of a 2 MVA series-stacked power-quality conditioner , 1999 .

[13]  Holmes,et al.  Pulse width modulation for power converters , 2003 .

[14]  Thomas A. Lipo,et al.  Pulse Width Modulation for Power Converters: Principles and Practice , 2003 .