To transfer large amount of direct current power having high amplitude voltage over long distance, high voltage direct current (HVDC) transmission system is used. This system was introduced 60 year ago and now it is widely used all over the world. Some examples of HVDC systems are following; Voltage-SourcedConverter (VSC), current commutated converter (CCC) and line commutated converter (LCC) d...

The application of high voltage dc (HVDC) transmission for integrating large scale and/or off-shore wind generation systems with the electric grid is attractive in comparison to extra high voltage (EHV) ac transmission due to a variety of reasons. While the technology of classical current sourced converters (CSC) using thyristors is well established for realization of large HVDC systems, the te...

For AC railway power supply systems with a different frequency than the public grid, high-voltage AC (HVAC) transmission lines are common, connected to the catenary by transformers. This paper suggests an alternative design based on an HVDC (High Voltage DC) feeder, which is connected to the catenary by converters. Such an HVDC line would also be appropriate for DC-fed railways and AC-fed railw...

HVDC transmission systems are becoming increasingly popular when compared to conventional AC transmission methods. HVDC voltage source converters (VSC) can offer advantages over traditional HVDC current source converter topologies; as such, it is expected that HVDC-VSCs will be further exploited with the growth of HVDC transmission. This paper presents the DC fault ride through capability and n...

Voltage Source Converters (VSC) have for the first time been used for HVDC transmission in a real network. Experience from the design and commissioning of the transmission shows that the technology has now reached the stage where it is possible to build high voltage converters utilising Insulated Gate Bipolar Transistors (IGBTs). Operation and system tests have proved that the properties that h...

Voltage Source Converter-High Voltage Direct Current (VSC-HVDC) is the most efficient and reliable method for electrical power transmission over long distances. The greatest challenge with VSC-HVDC system is that short-circuit faults damages the converter valves and the transmission network. The fault clearing time for the available DC breakers are not fast enough and reliable to provide adequa...

Most of the wind power plants currently installed at North Sea are near to shore connected with the onshore grid through AC cable. AC transmission technology is proven and reliable, but there will be a need to switch from AC to DC transmission since large number of offshore power plants at longer distance to shore are expected to be installed by the end of 2020. Furthermore, to enhance the inte...

High Voltage Direct Current (HVDC) systems offer distinct advantages for the integration of offshore wind farms to inland grid system. HVDC transmission system based on Voltage Source Converter (VSC) enables multi-terminal use HVDC for the integration of large-scale wind power in the North Sea. That network requires a special formulation for power flow analysis as opposed to the conventional me...

High-voltage dc transmission based on voltage-source converter (VSC-HVdc) is quickly increasing its power rating, and it can be the most appropriate link for the connection of offshore wind farms (OWFs) to the grid in many locations. This paper presents a steady-state operation model to calculate the optimal power transmission of an OWF connected to the grid through a VSC-HVdc link. The wind tu...

Priority access of renewable resources such as offshore wind recommended by European energy directives, new market models and trading the electric energy among countries lead to new requirements on the operation and expansion of transmission grids. Since AC grid expansions are limited by legislative issues and long distance transmission capacity, there is a considerable attention drawn to appli...