Assessment of protection strategy options for future DC grids
This paper proposes a set of measurable Key Performance Indicators (KPI) that demonstrates how effective a protection strategy is achieving key objectives.
Phd Ragavendran RAMACHANDRAN “Control and Power Management of an Offshore Wind Power Plant with a Diode Rectifier based HVDC Transmission”
Energy Transition for a more sustainable world is now the priority in societies. Towards this objective, especially in Europe, the offshore wind energy development has been relatively rapid. For Offshore Wind Power Plants (OWPP) farther from the shore (50 km and beyond) Voltage Source Converter (VSC) based High Voltage DC (HVDC) Transmission has become the prominent solution. Replacement of the offshore VSC station by multiple Diode Rectifier Units (DRUs) led to a cheaper, more compact and robust solution. This thesis focusses on various technological and scientific problems involved in the control system of the Offshore Wind power Plant with Diode Rectifier (DR) based HVDC transmission. These challenges are first reviewed in detail along with the state of the art. Then, based on the system dynamics, a grid forming control scheme is proposed by using the P-V and Q-f droop relationships, with a solution for the synchronization of the wind generators. Moreover, some of the selected control solutions in the literature for this topology are reviewed, compared and assessed by using time domain simulations of a study case. Following this, the different solutions for black start of the offshore AC system are analyzed from the available literature and they are compared using the relevant qualitative criteria. The various faults in the offshore system are then analyzed and the above designed grid forming control scheme is extended with Fault Ride through (FRT) capability, for offshore AC grid faults. Finally, a brief analysis is done on the challenges for the integration of this OWPP topology into a Multi Terminal DC (MTDC) network.
The renewables integration via HVDC grids
The large-scale integration of renewable electricity generation poses both structural, economic and management challenges. Among the major challenges, one can note the grid integration and the routing of this energy from the production units to the consumption poles. Major issues have to be faced like insufficient transmission capability, inertia reduction, stability margins mitigation. The HVDC is not a new idea but it can provide some interesting answers to these challenges. The keynote will list the locks and how they can be addressed by the HVDC grid. Finally, the underlying scientific issues will be discussed.
Phd Guilherme DANTAS DE FREITAS “Development of a methodology for DC grid protection strategies comparison”
High Voltage Direct Current (HVDC) grids are considered a promising solution for problems faced by nowadays power system such as: lines congestion, integration of large amounts of renewable power and enhancement of AC system stability. Among the challenges in the deployment of a HVDC meshed grid, the protection of these grids is regarded as one of the most critical. The protection of HVDC grid is challenging not only because the swift transients and fault currents without zero-crossing, but also due to the impact a DC faults can have on the AC system. Several propositions for HVDC grids protection strategies can be found in literature...
Ahmed Zama honored with the IEEE “Doctorate Laureate” for his thesis work
Every year the French chapter of IEEE Power & Energy Society (PES), in collaboration with SEE (Society of Electricity, Electronics and Information and Communication Technologies), recognises outstanding PhD theses and hands out the “outstanding engineer of the year” prize at an annual evening ceremony. This Wednesday the 9th of October, Ahmed Zama was honoured with the IEEE “Doctorate Award” for his thesis work on “Modeling and Control of Modular Multilevel Converters (MMCs) for HVDC applications”.
On the Black Start of Offshore Wind Power Plants with Diode Rectifier based HVDC Transmission
This paper attempts a detailed comparison of some of the solutions for black start of the Offshore Wind Power Plants with Diode Rectifier based HVDC transmission.
Tuning of Droop Parameters Using Virtual Capacitor Control to Improve Voltage Dynamics
This paper proposes a new approach to tuning voltage droop parameters in an MMC-based multi-terminal HVDC system. Using the new degree of freedom offered by the virtual capacitor control, the transient behavior of the DC voltage can be improved without adverse effects on the connected AC grids.
Pole-to-ground fault protection strategy for HVDC grids under symmetrical monopolar configuration
An experimental study of breakdown and pre-breakdown phenomena in liquid nitrogen (LN2) is performed in this paper, in order to provide useful knowledge for the design of high voltage superconducting systems.
SuperGrid Institute’s participation in PROMOTioN’s Work Package 9
SuperGrid Institute is proud to have been an active participant in the PROMOTioN project since 2016. This project is part of the European Union’s Horizon 2020 program and is made up of several work packages (WP) that share a common aim: developing meshed HVDC offshore grids that are both cost effective and reliable, through technological innovation. SuperGrid Institute is an active member of several Work Packages, including WP9 whose objective is to develop fault clearing strategies using Hardware-in-the-Loop (HIL) real-time simulation (RTS).
SuperGrid Institute presents a brilliant innovation at CIGRE-IEC 2019 in Japan
The Energy Management Control of MMC by SuperGrid Institute was presented in Japan this week at the CIGRE-IEC 2019 Conference on EHV and UHV (AC & DC), generating stimulating discussions about this new technology.
