Solid-state DC breaker switch the only option to ensure grid protection electric ferry Svelvik

On January 1, 2022, Sefine Shipyard successfully launched the battery-powered passenger and car ferry Svelvik. This electric ferry now operates between the Norwegian towns of Svelvik and Verket. To protect the onboard DC grid in the most reliable and efficient way, the Turkish system integrator Elkon opted for the 500 Ampere 1 kV Astrol solid-state DC breaker switch.

Grid protection battery powered ferry

In February 2020, Sefine Shipyard signed a contract for several electric ferries with the Norwegian ferry operator Basto Fosen.

The innovative and battery-powered electric ferry, designed by The Norwegian Ship Design Company, is 54 meters long and has a capacity of 99 passengers and 30 cars. The HVAC systems include a specially designed central heating/cooling system, utilizing both the hot and cold sides of the heat pumps simultaneously. 

Thanks to the low-emission generators and a battery capacity of 407 kWh, this type of ship is environmentally friendly and leaves a minimal ecological footprint. 

A design with focus on zero emission

Protecting the onboard microgrid

Elkon as renowned and successful supplier of electrical power system engineering, design and integration for vessels was able to contract as electrical system integrator for this series of hybrid electric ferries. The Turkish specialist cooperated with KWx when it came to develop a suitable solution for the safety design of the DC system.

Özgür Arslancan, Director Concept Design & Technology at Elkon and responsible for the technical design of the power system, explains what the biggest challenges were in this project: “In case of a short circuit, it is important that the ‘healthy’ side of the DC grid remains operational. This is a requirement of the certified bodies, in this case DNV. After all, the ship must never become out of control under any circumstances. To achieve this, extremely fast switch-off times and selectivity between different parts of the DC grid are required. We have explored the various options, but the only way to guarantee the required selectivity in different scenarios is the Astrol solid-state DC breaker switch. The ultra-fast switch-off times of just a few microseconds are crucial.” 

The electrical design

The electrical design of NB44 Svelvik is simplified in this section of the single line diagram. It shows that the Astrol DC breaker switch is placed between DC switchboard 1 and DC switchboard 2.

Single line diagram NB44 Svelvik

About Elkon

Founded in 1980, Elkon Elektrik (elkon) has been a renowned authority in the development, design, assembly, engineering and integration of systems in the area of electrical propulsion technology, electric systems and automation for the maritime industry for more than 40 years. The range of demanding applications is wide. At its headquarters in Tuzla (Istanbul) and its second R&D centre at Teknopark, elkon is the local market leader. With its subsidiary Elkon Norge AS, the specialized company is also directly available on site for customers in Norway and throughout Scandinavia for sales, after sales warranty services resp. services.

Ferry route Svelvik-Verket

With a sailing time of 5 minutes, Svelvik-Verket in Drammensfjorden is Norway’s shortest car ferry route. Bastø Fosen has been operating this ferry route since January 2022. The narrow strait of Svelvik – some 200 m wide and only 10m deep causes strong tidal currents. This 
makes maneuverability quite challenging for passing ships, 
including for the Svelvik-Verket ferry route. 

Specifications and features

  • Length: 54 meters
  • Beam moulded: 12.8 meter
  • Design depth3.1 meters
  • Capacity30 PCU / 99 passenger and crew
  • ClassDet Norske Veritas & DNV-GL
  • FlagNorway
  • Main propulsion engines2x 425 kW @1500 rpm
  • Main propellers2x 400 kW @700 rpm

Electric scope

  • Electric drive & propulsion equipment
  • Low voltage switchboards, consoles and equipment
  • Distribution boards 400/230V
  • Distribution boards 24V
  • Motor control centers
  • Individual motor starters
  • Low voltage switchboards, consoles and equipment
  • Miscellaneous panels / boxes
  • LV transformers
  • Battery chargers
  • Alarm control and monitoring System
  • Electrical engineering and installation

More about our solid-state DC breaker

Learn more about how our solid-state DC breakers offer optimal protection for your DC grid. View all our available solid-state DC breakers in our product catalog.

More information about our IGBT based solid-state DC Breaker for marine applications

Specialist in Maritime DC solutions

Astrolkwx specializes in advising and supplying power electronics components and assemblies for DC systems on board ships. In addition to the revolutionary solid-state DC breaker technology, we also supply (super) capacitors, isolated rectifiers, fuses, heatsinks, resistors and blocking diodes.