PhD Courses in Denmark

Organizer: Assistant Professor Ariya Sangwongwanich – Aalborg University, ars@energy.aau.dk

Lecturers:
Professor Ariya Sangwongwanich – Aalborg University
Postdoc Mateja Novak – Aalborg University
Radu Dan Lazar – Danfoss Drives

ECTS: 2

Date/Time: 23/09/2024 – 24/09/2024

Deadline: 2 September 2024

Place: AAU Energy, Pontoppidanstraede 101 room 1.015, Aalborg, Denmark

Max no. of participants: 20

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.

• Day 1

• Introduction (0.5 hours)
• 3L-NPC converter topology and operating principles (1 hour)
• Advantages, challenges, and applications of 3L-NPC converters (1 hour)
• Carrier based modulation methods for 3L- NPC converters (1.5 hour)
• Model predictive control methods for 3L- NPC converters (1.5 hour)
• Hands-on exercises (1.5 hours)
 

• Day 2

• Reliability of 3L-NPC converters (1.5 hour)
• Impact of the control algorithm on the device and capacitor reliability (0.5 hour)
• Practical aspects and design considerations – industrial case study (2 hours)
• Hands-on exercises and Lab demo (3 hours)

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.