1. Title of Tutorial
Operation, Control, and Applications of Modular Multilevel Converters
2. Abstract (No more than 500 words. If the tutorial is accepted, this abstract will be published
on the conference website, program, and proceedings)
The modular multilevel converter (MMC) has been the subject of increasing importance for
medium- and high-power energy conversion systems, specifically high-voltage direct current
(HVDC) transmission. Over the past few years, there has been a significant effort towards
addressing the technical challenges associated with the operation and control of the MMC as
well as broadening its potential applications and exploiting its salient features. This tutorial
provides a comprehensive description and review on the most recent advances and contributions
on the operational issues, modeling, control, and modulation techniques of the MMC. This
tutorial also highlights the emerging applications of the MMC and outlines their associated
challenges
3. Outline of Tutorial (Outline would only define the topics and the subtopics that would be
covered. No detailed descriptions should be included in the proposal)
1. Introduction
1.1Multilevel converters and their features
1.2 Diode Clamped Converters
1.3 Flying Capacitor Converters
1.4 Cascaded Multilevel Converters
2. Fundamentals of Modular Multilevel Converters (MMCs)
2.1 Circuit Topologies and Submodule Configurations
2.2 Basic Operation
2.3 Steady-State Operation
2.4 Device rating issues
3. Control Aspects of the MMC
3.1Internal Dynamics of the MMC
3.2Modulation and Submodule Capacitor Voltage Balancing Strategies
3.3 Circulating Current Control
3.4 Closed-loop Control
3.5Pre-charging the Submodule Capacitor Voltages and Soft Startup
3.6Fault-Tolerant Operation of the MMC
4. MMC for HVDC Transmission Systems
4.1Technology Trend
4.2Control and Operational Challenges
4.3Operation under Faults and Unbalanced Conditions
5. MMC for Railway Intertie Systems
5.1Technology Trend
5.2 Control and Operational Challenges
6. MMCs for Variable-Speed Drive Applications
6.1Technology Trend
6.2 Control and Operational Challenges
7. Other Applications and Challenges
8. Future Trend
4. Lead Instructors (Name, affiliation, and contact information)
This tutorial will be instructed by equal efforts of:
Prof. Maryam Saeedifard, School of Electrical and Computer Engineering, Georgia Institute of
Technology, Atlanta, GA
Email: Maryam@ece.gatech.edu
Assoc. Prof. Staffan Norrga, Department of Electrical Energy Conversion, KTH Royal Institute
of Technology, Stockholm, Sweden
Email: norrga@kth.se
5. Other Instructor(s) if applicable (Name, affiliation, and contact information)
6. Instructor Bios: ~150 words each (Please provide a brief biography for each instructor,
describing the qualifications for presenting the proposed tutorial, including the work and
publications that are most relevant to the proposal)
Maryam Saeedifard (SM’11) received the Ph.D. degree in electrical engineering from the
University of Toronto, Toronto, ON, Canada, in 2008. She is currently an Assistant Professor in
the School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta,
GA, USA. Prior to joining Georgia Tech, she was an Assistant Professor in the School of
Electrical and Computer Engineering at Purdue University, West Lafayette, IN, USA (20102013) and a research scientist at ABB Corporate Research Center in Switzerland (2008-2009).
Her research interests include power electronics and applications of power electronics in power
systems. She is the recipient of the IEEE Richard M. Bass Award of the Power Electronic
Society in 2010. She is an associate editor of the IEEE Trans. on Power Electronics and IEEE
Trans. on Industrial Electronics.
Staffan Norrga was born in Lidingö, Sweden, in 1968. He received the M.Sc. degree in applied
physics from Linköping Institute of Technology, Linkoping, Sweden, in 1993 and the Ph.D.
degree in electrical engineering from the Royal Institute of Technology (KTH), Stockholm,
Sweden, in 2005. Between 1994 and 2011, he worked as a Development Engineer at ABB in
Vasterås, Sweden, in various power-electronics-related areas such as railway traction systems
and converters for HVDC power transmission systems. In the year 2000, he returned to academia
to engage in research on new power electronic converters employing soft switching and medium
frequency transformers, at the Department of Electric Machines and Power Electronics of the
Royal Institute of Technology. He currently holds a position as Associate Professor at the same
institution. His research interests include new converter topologies for power transmission
applications and grid integration of renewable energy sources. He is the inventor or co-inventor
of 12 granted patents and 13 patents pending and has authored or co-authored more than 60
scientific papers published at international conferences or in journals with peer review.
Both instructors have a long history of working on the subject of the multilevel converters and
HVDC systems in general, and the MMC, in specific. Below, there are list of the relevant
publications by the instructors.
1. M. Vatani, M. Saeedifard, and M. Hovd, “Indirect Finite Control Set Model Predictive
Control of Modular Multilevel Converters, IEEE Trans. on Power Delivery, 2014.
Accepted.
2. L. Wu, J. Qin, M. Saeedifard, O. Wasynczuk, and K. Shenai, “Efficiency Evaluation of
the Modular Multilevel Converter Based on Si and SiC Switching Devices for
Medium/High-Voltage Applications, IEEE Trans. on Electronic Devices, vol. 62, no. 2,
pp. 286 - 293, 2015.
3. M. Vatani, B. Bahrani, M. Saeedifard, and M. Hovd, “Indirect Finite Control Set Model
Predictive Control of Modular Multilevel Converters, IEEE Trans. on Smart Grid, 2014.
In press.
4. 4. S. Debnath, J. Qin, and M. Saeedifard, “Control and Stability Analysis of the Modular
Multilevel Converter under Low-Frequency Operation, IEEE Trans. on Industrial
Electronics, 2015. Accepted.
5. 5. J. Qin, M. Saeedifard, A. Rockhill, and R. Zhou, “Hybrid Design of Modular
Multilevel Converters Based on Various Types of SubModule Circuits for High-Voltage
DC Transmission Systems, IEEE Trans. on Power Delivery, vol. 30, no. 1, pp. 385 - 394,
2015.
6. S. Debnath, J. Qin, B. Bahrani, M. Saeedifard, and P. B. Mantovalleni, “ Operation,
Control, and Applications of the Modular Multilevel Converter: A Review”, IEEE Trans.
on Power Electronics, vol. 30, no. 1, pp. 37-53, 2015.
7. J. Qin and M. Saeedifard, “A Zero-Sequence Voltage Injection-Based Control Strategy
for a Parallel Hybrid Modular Multilevel HVDC Converter System, IEEE Trans. on
Power Delivery, 2014. In press.
8. J. Qin and M. Saeedifard, “Reduced Switching Frequency Voltage Balancing Strategies
for Modular Multilevel HVDC Converters,” IEEE Trans. on Power Delivery, vol. 28, no.
4, pp. 2403-2410, 2013.
9. S. Debnath and M. Saeedifard, “A New Hybrid Modular Multilevel Converter for Grid
Connection of Large Wind Turbines,” IEEE Trans. on Sustainable Energy, vol. 4, no. 4,
pp. 1051-1064, 2013.
10. J. Qin and M. Saeedifard, “Predictive Control of a Modular Multi-Level Converter for a
Back-to-Back HVDC Transmission System,” IEEE Trans. on Power Delivery, vol. 27,
no. 3, pp. 1538-1547, 2012.
11. M. Saeedifard and R. Iravani, “Dynamic Performance of a Modular Multilevel Back-toBack HVDC System,” IEEE Trans. on Power Delivery, vol. 25, no. 4, pp. 2903-2912,
2010.
12. Norrga, S.; Ängquist, L.; Ilves, K.; Harnefors, L.; Nee, H.-P., "Decoupled steady-state
model of the modular multilevel converter with half-bridge cells," Power Electronics,
Machines and Drives (PEMD 2012), 6th IET International Conference on , vol., no.,
pp.1,6, 27-29 March 2012
13. Dijkhuizen, F.; Norrga, S., "Fault tolerant operation of power converter with cascaded
cells," Power Electronics and Applications (EPE 2011), Proceedings of the 2011-14th
European Conference on , vol., no., pp.1,8, Aug. 30 2011-Sept. 1 2011
14. Ilves, K.; Antonopoulos, A.; Norrga, Staffan; Nee, H.-P., "Steady-State Analysis of
Interaction Between Harmonic Components of Arm and Line Quantities of Modular
Multilevel Converters," Power Electronics, IEEE Transactions on , vol.27, no.1,
pp.57,68, Jan. 2012
15. Harnefors, L.; Antonopoulos, A.; Norrga, S.; Angquist, L.; Nee, H.-P., "Dynamic
Analysis of Modular Multilevel Converters," Industrial Electronics, IEEE Transactions
on , vol.60, no.7, pp.2526,2537, July 2013
16. Ilves, K.; Antonopoulos, A.; Norrga, Staffan; Nee, H.-P., "A New Modulation Method
for the Modular Multileel Converter Allowing Fundamental Switching Frequency,"
Power Electronics, IEEE Transactions on , vol.27, no.8, pp.3482,3494, Aug. 2012
17. Antonopoulos, A.; Angquist, L.; Norrga, S.; Ilves, K.; Nee, H.-P., "Modular multilevel
converter ac motor drives with constant torque form zero to nominal speed," Energy
Conversion Congress and Exposition (ECCE), 2012 IEEE , vol., no., pp.739,746, 15-20
Sept. 2012
18. Ilves, K.; Antonopoulos, A.; Harnefors, Lennart; Norrga, Staffan; Angquist, Lennart;
Nee, H.-P., "Capacitor voltage ripple shaping in modular multilevel converters allowing
for operating region extension," IECON 2011 - 37th Annual Conference on IEEE
Industrial Electronics Society , vol., no., pp.4403,4408, 7-10 Nov. 2011
19. Modeer, T.; Nee, H.-P.; Norrga, S., "Loss comparison of different sub-module
implementations for modular multilevel converters in HVDC applications," Power
Electronics and Applications (EPE 2011), Proceedings of the 2011-14th European
Conference on , vol., no., pp.1,7, Aug. 30 2011-Sept. 1 2011
20. Ahmed, Noman; Norrga, Staffan; Nee, H.-P.; Haider, A.; Van Hertem, D.; Lidong
Zhang; Harnefors, Lennart, "HVDC SuperGrids with modular multilevel converters —
The power transmission backbone of the future," Systems, Signals and Devices (SSD),
2012 9th International Multi-Conference on , vol., no., pp.1,7, 20-23 March 2012