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Front. Inform. Technol. Electron. Eng.  2010, Vol. 11 Issue (8): 654-662    DOI: 10.1631/jzus.C0910559
    
New method for estimating flying capacitor voltages in stacked multicell and flying capacitor multicell converters
Arash Khoshkbar Sadigh*,1, Gevorg B. Gharehpetian2, Seyed Hossein Hosseini1
1 Faculty of Electrical & Computer Engineering, University of Tabriz, Tabriz 51666, Iran 2 Department of Electrical Engineering, Amirkabir University of Technology, Tehran 15914, Iran
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Abstract  Multicell converters are an interesting alternative for medium voltage and high power applications, because of the increased number of output voltage levels and apparent frequency. The two most significant types of multicell converter are the flying capacitor multicell (FCM) converter and its derivative, stacked multicell (SM) converter. Balancing flying capacitor voltages is an important constraint to the proper performance of FCM and SM converters. Thus, observation of the flying capacitor voltages used in active control is valuable, but using voltage sensors for observation increases cost and size of the converter. This paper deals with a new strategy to estimate the flying capacitor voltages of both FCM and SM converters. The proposed strategy is based on a discrete time model of the converter and uses only a load current sensor. The circuit was simulated using PSCAD/EMTDC software and simulation results were presented to validate the effectiveness of the proposed estimation strategy in observing the flying capacitor voltages. Simplicity is the most significant advantage of the proposed strategy, its performance being based on simple equations.

Key wordsFlying capacitor multicell converter      Stacked multicell converter      Flying capacitor voltage      Phase shifted sinusoidal pulse width modulation     
Received: 10 September 2009      Published: 02 August 2010
CLC:  TM464  
Cite this article:

Arash Khoshkbar Sadigh, Gevorg B. Gharehpetian, Seyed Hossein Hosseini. New method for estimating flying capacitor voltages in stacked multicell and flying capacitor multicell converters. Front. Inform. Technol. Electron. Eng., 2010, 11(8): 654-662.

URL:

http://www.zjujournals.com/xueshu/fitee/10.1631/jzus.C0910559     OR     http://www.zjujournals.com/xueshu/fitee/Y2010/V11/I8/654


New method for estimating flying capacitor voltages in stacked multicell and flying capacitor multicell converters

Multicell converters are an interesting alternative for medium voltage and high power applications, because of the increased number of output voltage levels and apparent frequency. The two most significant types of multicell converter are the flying capacitor multicell (FCM) converter and its derivative, stacked multicell (SM) converter. Balancing flying capacitor voltages is an important constraint to the proper performance of FCM and SM converters. Thus, observation of the flying capacitor voltages used in active control is valuable, but using voltage sensors for observation increases cost and size of the converter. This paper deals with a new strategy to estimate the flying capacitor voltages of both FCM and SM converters. The proposed strategy is based on a discrete time model of the converter and uses only a load current sensor. The circuit was simulated using PSCAD/EMTDC software and simulation results were presented to validate the effectiveness of the proposed estimation strategy in observing the flying capacitor voltages. Simplicity is the most significant advantage of the proposed strategy, its performance being based on simple equations.

关键词: Flying capacitor multicell converter,  Stacked multicell converter,  Flying capacitor voltage,  Phase shifted sinusoidal pulse width modulation 
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