Yaskawa Environmental Energy/The Switch is at #EHMExpo to introduce a unique, ultra-fast protection method to make low-voltage DC distribution on vessels safe, efficient and redundant. “We want to make it easier for the marine industry to change from AC because there are big benefits with DC distribution,” explained The Switch's Teemu Heikkilä, head of product line, converters, during the show. “DC is more efficient, but on top of that, it’s more flexible for integration with batteries, fuel cells and other likely future alternative energy sources.”
The Switch DC-Hub ensures vessels can continue operating at full power, unaffected by the detection and isolation of any electrical fault, with power secure for ride-through operations. The DC-Hub consists of two breakthrough components – an electronic DC breaker (EDCB) and an electronic bus link (EBL). Both guarantee selectivity and safety through ultra-rapid fault detection and disconnection. This ensures complete redundancy in DC power distribution for fully electric and hybrid vessels.
The EBL connects multiple DC-Hubs in a vessel’s DC distribution system to isolate faults, ensure redundancy and protect interconnections between multiple DC-Hubs. The EBL splits onboard grids in microseconds. It isolates any faulty DC-Hubs so other DC-Hubs are not affected. If a fault occurs, the EBL rapidly disconnects them to isolate the fault. Furthermore, the EBL enables a ring network to be formed from multiple DC-Hubs, ensuring redundancy no matter how large the system.
The Switch EDCB is an ultra-rapid semiconductor-based electronic breaker integrated inside inverter modules to protect against short-circuit faults. It increases redundancy within a DC-Hub by detecting, cutting and isolating any critical fault in 10 microseconds – much faster than the milliseconds needed to cut a conventional fuse.
“Fuses work for AC systems, but as the fault current in DC distribution does not have zero crossing, protection devices need much higher performance,” explained Heikkilä. The Switch concept is based on rapid current measurements and predictable protection.
The EDCB’s selectivity reduces fault duration and isolates any damage to just the affected module. This ensures the least-possible energy disruption. The EDCB can also be used, for example, to connect large batteries by blocking their high short-circuit current, which existing marine DC systems cannot handle.
Asbjørn Halsebakke, marine technical solutions manager, reported strong interest in the new power distribution solution: “We had our first visitor at 10am as soon as the show opened! This event is very compact, with a strong focus – it’s all about what we are doing and our solution is perfect for those people visiting, who can get a lot of information in one place. We meet our customers here, and our customers’ customers. We can show them how to take the steps from AC to DC, even in megawatt cases. Even before 11am on the first day we were discussing cases that are going to happen. This is the perfect place to be.”