PROJECT TITLE: Protection of Multi-Terminal VSC-HVDC Transmission Lines
PhD period: 2017.04.15 - 2020.04.14. (has been prolonged till 2020.07.15)
Section: Electric Power Systems
Research Programme: Modern Power Transmission Systems
Supervisor: Filipe Miguel Faria Da Silva
Co-Supervisor: Claus L. Bak
Collaborator: To be announced later.
High voltage direct current (HVDC) transmission is an established technology that has attracted a lot of attention along the development of the renewable energy generation technologies and has been improved significantly in recent years. Lately, the developments in semi-conductors and controlling methods have made voltage source converter (VSC) based HVDC lines available which will be widely used in future transmission networks as new economical way transmit power from remote offshore wind farms and interconnection of asynchronous ac regions with better performance and higher benefits compared to classics HVDC systems. Multiple wind farms can be connected to the grids by means of multi-terminal VSC-HVDC (MTDC), enabling high power transmission levels. A single MTDC transmission systems is preferred over multiple point-to-point HVDC transmission systems, having economic and technical benefits because of less converter stations. Most of HVDC protection methods are presented for two terminal HVDC systems which cannot be extended to MTDC transmission systems and the design of MTDC protection systems is considered to be in progress. The proposed method should be a fast algorithm able to provide high selectivity on various faults within its protection zone and discriminate faults outside its protection zone. The converter control techniques in MTDC systems are also very important, which give more benefits than classic HVDC like independent active and reactive control. This project will focus on new protection algorithms for multi-terminal VSC-HVDC connected on-shore and off-shore wind farms to the main AC grids, considering different control methods and network configurations. The method will be applied on a modelled system and various fault types will be simulated by PSCAD and MATLAB software, to analyze to quality of results and robustness of the method.
Publications in journals and conference papers can be found at VBN.