Description

The three-level neutral-point-clamped (3L-NPC) converters have been widely applied in several applications including motor drives and grid integration such as wind and solar energy systems. Key performance metrics of the 3L-NPC converters like power quality, efficiency, power density and reliability are strongly affected by the used control methods. Therefore, different control methods have been proposed for the 3L-NPC topology to address certain aspects. 

This course aims to address basic concepts and control design challenges of NPC converter applications. It will start with basic operating principles of the topology and their control challenges such as neutral point voltage balancing and thermal stress distribution. Then, two different control approaches will be presented: 1) carrier-based PWM techniques and 2) model predictive control techniques. For each control technique, basic concept and step-by-step implementation guideline will be provided, followed by more application-oriented examples and implementation challenges.

An approach to analyze the reliability of power electronics converters will also be introduced, which includes thermal stress modeling, lifetime prediction, and reliability evaluation (Monte Carlo simulation). It will be demonstrated that control algorithm selection has a major impact on the reliability of semiconductor devices and DC-link capacitors in NPC converters. In the last part of the course the focus will be set on practical application cases of NPC converters in the industry. 

The course is intended both for academia researchers and industry, who do not have previous knowledge about the NPC topology (basic operating principles will be explained), and for those who are familiar with the topology and would like to learn more about ongoing research directions and novel control solutions.  

Find the detailed course program on PhD Moodle: https://phd.moodle.aau.dk/course/view.php?id=2207 

Prerequisites

• Fundamentals of power electronics
• Experience with MATLAB/Simulink is recommended for the exercises 

Form of evaluation

Students are required to solve exercises using the knowledge acquired in the course and submit a short project report with solutions within three weeks after the course, which will be assessed by the lecturers.

Price

8000 DKK for the Industry and 6000 DKK for PhD students outside of Denmark (VAT-FREE Education)

The Danish universities have entered into an agreement that allows PhD students at a Danish university (except Copenhagen Business School) the opportunity to free of charge take a subject-specific course at another Danish university.
Read more here: https://phdcourses.dk/ 

Questions

hr@energy.aau.dk   

More information

https://www.energy.aau.dk/research/phd   

Course literature    

1. J. Rodriguez, S. Bernet, P. K. Steimer, and I. E. Lizama, “A survey on neutral-point-clamped inverters,” IEEE Trans. Ind. Electron., vol. 57, no. 7, pp. 2219–2230, 2010.
2. A. Nabae, I. Takahashi and H. Akagi, "A new neutral-point-clamped PWM inverter", IEEE Trans. Ind. Applications, vol. 17, no. 5, 1981.
3. T. Bruckner and D. G. Holmes, "Optimal pulse-width modulation for three-level inverters,“ IEEE Trans. Power Electron., vol. 20, no. 1, pp. 82-89, Jan. 2005.
4. S. Busquets-Monge, J. Bordonau, D. Boroyevich, and S. Somavilla, “The nearest three virtual space vector PWM - a modulation for the comprehensive neutral-point balancing in the three-level NPC inverter,” IEEE Power Electronics Lett., vol. 2, no. 1, pp. 11–15, 2004.
5. S. Vazquez, J. Rodriguez, M. Rivera, L. G. Franquelo, and M. Norambuena, “Model predictive control for power converters and drives: Advances and trends,” IEEE Trans. Ind. Electron., vol. 64, no. 2, pp. 935–947, Feb 2017.
6. J. Rodriguez and P. Cortes, Predictive Control of Power Converters and Electrical Drives, ser. Wiley - IEEE. Wiley, 2012 
7. H. Wang, M. Liserre, F. Blaabjerg, P. P. Rimmen, J. B. Jacobsen, T. Kvisgaard, J. Landkildehus, "Transitioning to physics-of-failure as a reliability driver in power electronics," IEEE J. Emerg. Sel. Topics Power Electron., vol. 2, no. 1, pp. 97-114, Mar. 2014. 
8. H. Wang and F. Blaabjerg, “Reliability of capacitors for DC-link applications in power electronic converters – an overview,” IEEE Trans. Ind. App., vol. 50, no. 5, pp. 3569-3578, Sep./Oct. 2014.