Abstract
Over the past years, modular multilevel converters (MMC) have been widely researched as a preferred option among voltage source converters for HVDC transmission system. The converter presents modularity to generate high number of output voltage levels by simple series connection of modules, resulting in higher reliability and easy failure management/maintenance. Synthesis of near sinusoidal output voltage waveforms by multilevel operation requires pulse-width modulation at relatively lower switching frequencies, resulting in reduced switching losses. In this paper, asymmetrical submodules in the MMC based HVDC system have been investigated. Use of asymmetrical submodules with different capacitor voltages results in lesser number of semiconductor switches for the same number of output voltage levels, thus reducing the overall size of the converter system. The operating principle using different carrier based modulation schemes is discussed in detail. Modified voltage balancing algorithms based on well known sorting algorithm and PI controller have been investigated for their feasibility to asymmetrical-MMC operation. Simulations with preliminary experimental results are presented to validate the proposed converter operation.
Original language | English (US) |
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Title of host publication | 2015 IEEE Energy Conversion Congress and Exposition, ECCE 2015 |
Publisher | Institute of Electrical and Electronics Engineers Inc. |
Pages | 4693-4699 |
Number of pages | 7 |
ISBN (Electronic) | 9781467371506 |
DOIs | |
State | Published - Oct 27 2015 |
Event | 7th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2015 - Montreal, Canada Duration: Sep 20 2015 → Sep 24 2015 |
Publication series
Name | 2015 IEEE Energy Conversion Congress and Exposition, ECCE 2015 |
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Other
Other | 7th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2015 |
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Country/Territory | Canada |
City | Montreal |
Period | 9/20/15 → 9/24/15 |
Bibliographical note
Funding Information:The authors would like to thank ONR (Office of Naval Research), Research Grant No. - N00014-13-1-0511 for their support.
Keywords
- Asymmetrical submodules
- High voltage direct-current (HVDC)
- Modular multilevel converter (MMC)
- Pulse-width modulation
- Voltage balancing algorithm