The new distribution and transmission grid as described in the WP1 and WP2 sections, requires the deployment of innovative technologies that will enable the operation of the grid. Multi-terminal DC transmission is not yet commercially used, but it is anticipated to be a relevant option for the system expansion or reinforcement in the near future. Additionally, the principles and technologies for isolating and accurately detecting the faults clearly differ from existing AC solutions.
Three classes of High Voltage Direct Current (HVDC) breakers have been discussed in the literature: mechanical, static and hybrid. Fast measurement and fault detection systems for HVDC are not yet available and none of these principles has yet been demonstrated at the required ratings. Similarly, fault-tolerant HVDC converters have been proposed, but they are not used as current commercial products.
Further research activities are also required in modular power electronic converters while in mixed frequency insulation material, the effects of the dielectric stress distribution will become an increasing hindrance in the future grids. However, our current understanding of these effects is limited.
- multi-terminal HVDC system design and operation;
- fault detection and clearing in multi-terminal HVDC;
- enabling technologies.
WP3’s objective include:
- Standardisation work (including procedures) allowing to accelerate Switzerland’s connection to multi-terminal DC networks,
- Facilitation of the emergence of a common DC fault management concept for the European interconnected network,
- Investigation of key power electronic technology issues to be solved in order to establish cost efficient and reliable converters for transmission applications.
Storage system in MV for grid auxiliary services
Innovative interface of storage systems for MV applications, making use of modular converters and avoiding the 50Hz main transformer
Fault clearing in multi-terminal HVDC
For the safe operation of future HVDC multi-terminal grids, HVDC circuit breakers are a key component. Advances in HVDC switching technology will enable the Swiss energy industry to take a leading role in the world-wide transition from fossil to renewable energy sources.
Dry-Type Insulation Systems under Mixed-Frequency MV Stress