The Effects of Voltage Level Number on Operation Characteristics of Modular Multilevel Converter

Abstract:

The effects of total voltage level number (TVLN) on behaviors of the modular multilevel converter (MMC) are analyzed in this paper. First, it gives a brief introduction on the MMC system for how the converter generates multilevel staircase waveform. Second, the operation characteristics during the start process are analyzed. The capacitor voltage of a SM, the DC voltage, the exchanging power, and the DC loop current would be all influenced by different TVLNs. Third, the harmonic components in steady state are discussed to reveal the reason why the total harmonic distortion (THD) of the output voltage of MMC reduces when the TVLN increases. Simulation results show the validation of the conclusions drawn in this paper. Furthermore, when the TVLN is small, the THD in SUPWM method is lowest. However, when the TVLN increases, especially greater than 11, the THD in CPS-SPWM method is lowest.

• Periodical: Applied Mechanics and Materials (Volumes 556-562)
• Pages: 1902-1908
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.556-562.1902
• Online since: May 2014
• Authors: Jia Long Li*, Hai Feng Li, Chong Ru Liu, Geng Yin Li, Zhou Hong Lin
• Keywords: Modular Multilevel Converter, Operation Characteristic, Total Harmonic Distortion (THD), Total Voltage Level Number

References

[1] Sood V K, Khatri V, Jin K. EMTP modelling of CIGRE benchmark based HVDC transmission system operating with weak AC systems[C]/Power Electronics, Drives and Energy Systems for Industrial Growth, 1996, Proceedings of the 1996 International Conference on IEEE, 1996, 1: 426-432.

DOI: 10.1109/pedes.1996.539653

[2] Karlecik-Maier F. A new closed loop control method for HVDC transmission[J]. IEEE transactions on power delivery, 1996, 11(4): 1955-(1960).

DOI: 10.1109/61.544282

[3] Flourentzou N, Agelidis V G, Demetriades G D. VSC-based HVDC power transmission systems: An overview[J]. Power Electronics, IEEE Transactions on, 2009, 24(3): 592-602.

DOI: 10.1109/tpel.2008.2008441

[4] Das A, Nademi H, Norum L. A pulse width modulation technique for reducing switching frequency for modular multilevel converter[C]/Power Electronics (IICPE), 2010 India International Conference on IEEE, 2011: 1-6.

DOI: 10.1109/iicpe.2011.5728082

[5] Gemmell B, Dorn J, Retzmann D, etal. Prospects of multilevel VSC technologies for power transmission[C]/Transmission and Distribution Conference and Exposition, 2008. TD. IEEE/PES IEEE, 2008: 1-16.

DOI: 10.1109/tdc.2008.4517192

[6] Ilves K, Antonopoulos A, Norrga S, etal. Steady-state analysis of interaction between harmonic components of arm and line quantities of modular multilevel converters[J]. Power Electronics, IEEE Transactions on, 2012, 27(1): 57-68.

DOI: 10.1109/tpel.2011.2159809

[7] Qingrui Tu, Zheng Xu. Impact of sampling frequency on harmonic distortion for modular multilevel converter[J]. Power Delivery, IEEE Transactions on, 2011, 26(1): 298-306.

DOI: 10.1109/tpwrd.2010.2078837

[8] Allebrod S, Hamerski R, Marquardt R. New transformerless, scalable modular multilevel converters for HVDC-transmission[C]/Power Electronics Specialists Conference, 2008. PESC 2008. IEEE, 2008: 174-179.

DOI: 10.1109/pesc.2008.4591920

[9] Zixin Li, Ping Wang, Haibin Zhu, etal. An improved pulse width modulation method for chopper-cell-based modular multilevel converters[J]. Power Electronics, IEEE Transactions on, 2012, 27(8): 3472-3481.

DOI: 10.1109/tpel.2012.2187800

[10] Saeedifard M, Iravani R. Dynamic performance of a modular multilevel back-to-back HVDC system[J]. Power Delivery, IEEE Transactions on, 2010, 25(4): 2903-2912.

DOI: 10.1109/tpwrd.2010.2050787

[11] Hagiwara M, Akagi H. Control and experiment of pulsewidth-modulated modular multilevel converters[J]. Power electronics, IEEE Transactions on, 2009, 24(7): 1737-1746.

DOI: 10.1109/tpel.2009.2014236

[12] Das A, Nademi H, Norum L. A method for charging and discharging capacitors in modular multilevel converter[C]/IECON 2011-37th Annual Conference on IEEE Industrial Electronics Society IEEE, 2011: 1058-1062.

DOI: 10.1109/iecon.2011.6119454

[13] Shi K, Shen F, Lv D, etal. A novel start-up scheme for modular multilevel converter[C]/Energy Conversion Congress and Exposition (ECCE), 2012 IEEE, 2012: 4180-4187.

DOI: 10.1109/ecce.2012.6342255