Modeling and simulation of HVDC power convertersMaster 2 Internship

Keywords:

High Voltage Direct Current (HVDC), modeling and simulation, power converters.

Context:

High-voltage direct current (HVDC) transmission systems are becoming more and more important in an energy

landscape that is characterized by increasing digitalization, decarbonization, and distributed generation. HVDC

technology offers the most efficient means of transmitting large amount of power over long distances through overhead,

underground and offshore links.

For HVDC links using voltage source converters (VSC), the Modular Multilevel Converter (MMC) has acquired

an industrial maturity and is becoming a standard. Until this date, the technology has been implemented in HVDC

links up to 1400 MW [1].

The development of power electronic systems usually involves the design of both the electrical circuit and the

control algorithms based on detailed simulations. The complexity of the simulation model is directly related with the

frequency range of the dynamics that one may want to capture. Inside a power converter, many events will take

place in different time-scales such as the switching transition of solid state devices, the modulation of current and

voltage wave-forms and the power flow dynamics.

Figure 1 – Example of real-life challenges requiring advanced power electronics models.

Objective:

The main objective of this internship is to develop and validate a new model of the MMC. The work will be

based on previous development and investigations within the scope of the ongoing PhD thesis of Rafael Medeiros

(EDF/GeePs).

Workflow:

The workflow of the internship could be organized as follows:

1. Review of modeling of static power converters

2. Review of the operation of grid-connecter power converters

3. Deployment of the proposed model of the 2-level VSC in open loop

4. Deployment of the proposed model of the 2-level VSC in closed loop

5. Comparison of the results with an averaged time-domain model

6. Extension of the work to the MMC

7. Redaction of a journal article

The candidate should be comfortable with static power conversion and Matlab/Simulink (SimPowerSystem tool-

box or Plecs). Curiosity, autonomy and initiative are very much appreciated. The internship will take place at the

GeePs laboratory, in CentraleSuplec, Gif campus.

References:

[1] R. Marquardt, ”Modular Multilevel Converters: State of the Art and Future Progress,” in IEEE Power Electronics

Magazine, vol. 5, no. 4, pp. 24-31, Dec. 2018.doi: 10.1109/MPEL.2018.2873496

[2] E. Mollerstedt and B. Bernhardsson, ”Out of control because of harmonics-an analysis of the harmonic response

of an inverter locomotive,” in IEEE Control Systems Magazine, vol. 20, no. 4, pp. 70-81, Aug. 2000. doi:

10.1109/37.856180

Period:

Between 01/03/2020 and 01/10/2020 for a period of 4-6 months.

Contact:

1. Loic Queval (GeePs), loic.queval@geeps.centralesupelec.fr

2. Jing Dai (GeePs), jing.dai@geeps.centralesupelec.fr

3. Rafael Medeiros (EDF/GeePs), rafael.coelho-medeiros@edf.fr