Performance Demonstration of HVDC substation equipment
The EU funded project “Progress on Meshed HVDC Offshore Transmission Networks” (PROMOTioN) addresses the challenges for meshed HVDC offshore network development. The project does not only perform the demonstrations of different HVDC Breakers, it also gives recommendations of how to test HVDC Breakers, and insight into typical requirements and expectations of HVDC Breakers in a grid. The project will finish in 2020 and all public material can be found on the project website. There is a need to move this work into standardization bodies to get an agreed and satisfactory testing procedure for the HVDC Breakers as well as for the non-linear resistors.
The increasing demand for HVDC technology requires the adaptation of gas insulated switchgear (GIS).
Based on the development and research results combined with the service experience a new type test philosophy including insulation system tests was developed. If future offshore grids would be considered with multi-terminal or switching stations offshore, the gain would be considerably larger. Moreover, the gas-insulated components can be applied in various HVDC applications.
This paper explains that the new components in an HVDC substation are far into the development phase and are on a clear path to an even higher Technology Readiness Level (TRL). The activities to increase the technical assurance to implement these components in the grid as described.
Once the HVDC substation equipment has been implemented into HVDC systems, and the experience should be collected on how they are actually being used, to develop more cost efficient solutions.
Innovations, Developments & Remaining Challenges for UHV Insulator Design
In this report the design issues and solutions related to external and internal insulation design of insulators for UHV applications have also been reviewed with emphasis on the post insulators made of composite hollow-cores.
Abstract Cable Over Voltage for MMC based VSC HVDC System Interaction with Converters
In this paper we do not claim an investigation of the highest of all possible overvoltages, instead we focus on an important case in the ongoing discussion, which is an overvoltage type occurring in a symmetrical monopolar HVDC system. Symmetrical monopolar HVDC systems are today among the most common installed system topologies. In the presented case a +/-320 kV dc system is studied, where two MMC VSC stations are connected via 225 km long sea cable. Parameter variations, such as fault location, location of occurring overvoltage and cable length, are investigated on a specific basis, and tendency of their impact is presented.