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 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.
This work proposes a method for the full development, from conception to implementation, of the supervisory control of a multi-terminal HVDC (MT-HVDC) system.
The objective of this study is to propose a methodology for the transient stability assessment of a simple but representative AC grid in case of DC fault. After validation of the methodology, some HVDC link protection criteria are defined in terms of the Critical Time to Return to Operation. These criteria will be helpful for the design of HVDC protection systems or for the sizing of future HVDC links in order to respect the constraints of the existing protection strategies.
AC Grid Forming by Coordinated Control of Offshore Wind Farm connected to Diode Rectifier based HVDC Link-Review and Assessment of Solutions
This paper reviews a few of the major control solutions for AC grid forming and operation of DR-HVDC based OWFs. Then these solutions are compared based on their approach in solving the major challenges involved.
This paper presents a novel protection scheme based on converter breaker; its key element, namely a low-speed mechanical DC breaker, is located at each DC converter output.