Solid-state DC Breaker Switch the only option to ensure grid protection electric ferry Svelvik


Maritieme toeleveranciers, Scheepsbouw

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.

Protecting the onboard DC micro-grid

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 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.

Designed with a focus on zero emissions

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.

Continue reading on the KWx website.