This paper presents an overview of the dc–dc power converters dedicated to HVdc proposing a classification based on their structure. Two large families are established: those which provide galvanic isolation, and those which do not. Several subfamilies are also proposed. An overview of the main HVdc applications that can be targeted with each family is also presented, highlighting the main converter requirements for each application case.
PhD Amjad MOUHAIDALI “Contribution to the modelling of HVDC cables for electromagnetic transient simulations”
The integration of new technologies in the electric grids made them more and more complex, and most likely future growth of power grids will be based more on underground cables than overhead lines. One problem here, is that the mathematical model for electromagnetic simulation of power cables still has some shortcomings regarding stability, accuracy and passivity. In this thesis, we evaluate the cable parameters using analytical and numerical methods.
This paper provides a fault analysis of bipolar overhead line based HVDC grids using HB-MMC converters. The impacts of fault type and fault resistance are shown and the physical behaviour of the transient fault return current is explained.
Power system stability enhancement via VSC-HVDC control using remote signals: Application on the Nordic 44-bus test system
In this paper the benefits of embedded VSC-HVDC links with supplementary controls for small-signal stability enhancement purposes using remote signals are studied and applied on the Nordic Grid.
This thesis addresses the transient stability analysis of hybrid AC/DC electric transmission systems. More precisely two questions sought to be investigated: What is the impact of a DC contingency on AC transient stability? How can we take advantage of the DC transmission systems as control inputs in order to enhance AC transient stability?
SuperGrid Institute is delighted to have signed a framework agreement with the CNAM (Conservatoire National des Arts et Métiers) regarding training and in particular around supergrid and HVDC technologies. This agreement covers lifelong learning, technology research and the provision for scientific and technical proficiency.
This paper presents a methodology to consider the impedance of a grid in power hardware in the loop (PHIL) experiments to validate power converter control in presence of harmonics or resonances in the network impedance. As the phenomena to emulate are in a large frequency range, the skin effect in conductors has to be taken into account. A procedure is developed to model the network.
This paper presents a methodology for the modelling of a 25 kV-50 Hz railway infrastructure, for frequencies from 0 to 5 kHz. It aims to quantify the amplifications of current and voltage harmonics generated by on-board converters into the infrastructure. A circuit is developed to model the skin effect in the overhead line for time-domain simulations. A new approach, based on state space representation and transfer functions, is also proposed to analyse the interactions between trains.
PhD Quentin MOLIN “High Voltage SiC MOSFET Robustness study: threshold voltage shift and short-circuit behaviour”
This manuscript is a contribution to reliability and robustness study of MOSFET components on silicon carbide “SiC”, wide band gap semiconductor with better characteristics compared to silicon “Si” material. Those new power switches can provide better switching frequencies or voltage withstanding for example in power converter. SiC MOSFET are the results of approximately 10 years of research and development and can provide increased performances and weight to some converter topology for high voltage direct current networks.
SuperGrid Institute and IMDEA joint forces with the support of REE, and created a consortium. This consortium was selected from more than 80 projects. Through the "Reduced Inertia Transient Stability Enhancement" (RITSE) project, SuperGrid Institute will strive to improve the transient stability of the AC networks by coordinating the use of batteries and HVDC links.