Maritime energy storage system (ESS) manufacturer Corvus Energy is to join forces with Finland-based power electronics specialist Yaskawa Environmental Energy, also known as The Switch, to develop smart Battery Short-Circuit Limiter (BSCL) protection for large-scale battery solutions and advanced DC power distribution.
Under a three-year memorandum of understanding (MoU), Corvus Energy becomes the preferred partner for Yaskawa Environmental Energy / The Switch in the ongoing development of its proprietary BSCL device. The agreement includes the joint promotion of each party’s products.
The Switch President Miika Reinikka said: “We are very happy to be working with Corvus Energy as a world leader in marine ESS and look forward to constructive collaboration and teamwork.”
Corvus Energy CEO Geir Bjørkeli said: “We are pleased to join forces with Yaskawa Environmental Energy / The Switch. Their unique skill in thinking outside the box to solve complex challenges makes them a valuable partner on our journey to decarbonise shipping. Their innovative technology makes a big difference for the utilization, scalability and safety of marine battery systems.”
Connecting high-energy-content batteries to one electrical system carries high risk of releasing a massive amount of short-term current that can result in system damage. Battery packs consequently have to be split between several DC hubs to handle the amount of energy. The more batteries hooked up, the more DC hubs would be required – theoretically up to eight for a 20 MWh ESS. The innovation BSCL brings is to limit short-term current from each set of batteries, immediately blocking the short-circuit system. This allows more batteries to be connected to the electrical system with fewer DC hubs, making the system more compact and representing a significant financial saving. The space saving in terms of cabinet length means lower CAPEX while at the same time promoting safety, efficiency and reliability.
Teemu Heikkilä, Head of Product Line, The Switch, explained: “The BSCL is essentially an ultra-fast, semi-conductor-based protection device that operates based on actual system measurements with microsecond response. It opens the DC electrical circuit by disconnecting a battery set in the event of a fault anywhere in the system, preventing the battery set from discharging itself. Such a sudden release of energy could result in major damage and, in the worst case, an electrical fire. BSCL minimises the risk by stopping the energy loss in microseconds. From a technical perspective, the market hasn’t yet come to grips with this connectivity challenge. Class rules, which were primarily designed for AC/DC systems, are lagging behind the rapid pace of technology in DC power distribution. The BSCL is the first product fit for purpose with battery systems that are getting bigger almost by the day. Its key benefit, mirroring the electrification trend where the larger the ESS the better, is that you can increase the energy content of the ESS while minimising the number of parallel systems required. In principle, implementing BSCL means you still only need two DC hubs for an ESS up to 40 MWh, so the savings grow in tandem with the size of the battery package.”
While battery systems on board ships until now have been limited to below 10 MWh installations, future projects are increasing to many times this size. The device works for the entire Corvus ESS portfolio, including Corvus Orca, but is particularly suited to Corvus Energy’s Blue Whale ESS, which is designed to meet large operational energy demands at a cost-effective kWh price. The Blue Whale system has been specifically developed for large battery installations ranging from 10 MWh and upwards. Typical vessel applications include cruise ships as well as large ferries, yachts, merchant ships, inland vessels and workboats.
The BSCL is a standalone product to be placed close to the batteries and between drives. The space saving it generates complements Blue Whale’s low weight and low total system volume. The BSCL can be retrofitted to existing systems for extra security.
The BSCL is closely related to Yaskawa Environmental Energy / The Switch’s recently launched Electronic Bus Link (EBL) and Electronic DC Breaker (EDCB) devices that serve to guarantee selectivity and safety through ultra-rapid fault detection and disconnection, ensuring redundancy in DC power distribution for fully electric and hybrid vessels. Both devices are now standard building blocks in the company’s marine drive offering. They enable The Switch DC hubs to perform with efficiency and reliability, delivering system protection and ride-through capability.
