Finnish marine power electronics specialist The Switch has introduced an Electronic Current Limiter (ECL) to address a growing challenge in modern hybrid and electric vessels: how faults in large battery systems can affect the rest of the ship. As batteries play a larger role in vessel propulsion, power generation, and energy storage, a fault on the battery side is no longer a local issue.
Without sufficiently fast protection, sudden fault currents can pull voltage down across the shared DC system, causing healthy equipment to trip or shut down and turning a contained technical issue into a wider operational disruption. Installed between batteries and the DC-Hub, the ECL limits fault current during abnormal conditions before it can propagate into the DC system, preserving DC-link voltage and ride-through capability, allowing other consumers to continue operating.
The ECL builds on The Switch's established suite of semiconductor-based protection devices for DC distribution, including Electronic DC Breakers (EDCBs), integrated inside inverter modules, which isolate internal faults within microseconds, ensuring failures are contained locally without destabilizing the DC-Hub, and Electronic Bus Links (EBLs) providing selective protection between DC-Hubs. Battery Short-Circuit Limiters (BSCLs) address the growing short-circuit energy associated with large battery installations by preventing that stored energy from being released into the DC system during a fault.
The ECL complements these technologies by focusing specifically on faults on the battery side, particularly in configurations where batteries are connected directly to the DC link. By allowing batteries to connect directly to the DC link, the ECL enables simpler system architecture with fewer conversion stages, increasing vessel efficiency and reducing footprint, while ensuring predictable behavior during faults thanks to its fast, selective protection.
For shipowners, the benefit is not only efficiency but operational resilience, as vessels can continue operating or exit operations safely, rather than experiencing blackouts or cascading system failures. The ECL's introduction reflects a broader shift in marine power system design, where failure behavior and ride-through capability are treated as core design criteria rather than afterthoughts.