The benefits of streamlining electric drives are minimal energy losses, improved environmental performance, and lower operating costs.
Speaking about electric drives, Managing Director of Western Hemisphere at BERG Propulsion in Sweden
It is believed that with the increase in marine hybrid and electric applications, many traditional components in modern electric propulsion ships are being replaced by new technologies and components. “Traditionally, ship propulsion has been provided by a fossil-fuel-burning host driven propeller through a reducer. In new applications, power can be split from the gearbox, supplied via a frequency converter, and then delivered to the distribution box. This method is great and straightforward. As the largest power consumer, the propeller can get power from the power source immediately. ”
“In conventional diesel-electric propulsion applications, the three main components are the propeller, reducer and electric motor. And to reduce parts and increase efficiency, we improved the configuration of the direct electric drive, making the motor part of the shaft train. In a patent-pending configuration, we place the rotor of the motor on the propeller shaft and the motor stator on the hull. The propeller shaft is the electric motor. This is equivalent to introducing a very new concept. “BERG Propulsion has been designing and manufacturing propulsion systems for more than 100 years as a manufacturer and system integrator of propulsion systems, and today the company is looking for the simplest solutions to realize new propulsion technologies for ships.
BERG Propulsion is exploring the use of Superdrive, a DC hub that connects vessel energy storage and power generation for distribution, and is being used for a new bulk carrier owned by Canada Steamship Company (CSL) built at a Chinese shipyard. “This is the first ship to feature a patent-pending direct-drive propulsion unit with an electric motor as part of the shafting system, an application that will transform some parts of electric propulsion in the marine industry.”
In the case of CSL Bulk Carrier, BOGE is working with The Switch, a developer of advanced driveline solutions, to provide an innovative set of electric drivetrain technologies in two-fin propulsion systems. The Switch supplied two permanent magnet (PM) propulsioners, four permanent magnet generators, two DC hubs, two Electronic Bus Links (EBLs) and 20 electronic DC circuit breakers (EDCBs) for the vessel. “Compact, lightweight, efficient and easy-to-maintain permanent magnet technology captures mechanical energy and converts it into electric ship power, ideal for the limited available space in the thin double fin.” According to The Switch, DC hubs provide flexible options for power generation, energy storage, charging, propulsion and clean power, EBL connects and protects them, and EDCBs are installed to protect the individual drives within the DC hub. Bulk carriers with new electric drives are equivalent to large in-house power plants to meet cargo conveyor belts, propulsion units and related operational needs.
When it comes to hybrid propulsion, it is unfair to talk only about diesel engines.
More applications in the future will be LNG engines, methanol engines and ammonia fuel engines. “Hybrid applications play an important role in the configuration of specific systems, which are related to vessel performance and fuel consumption expectations, battery integration and powertrain electrification. Electric drive systems are a step-by-step change to traditional ship propulsion systems, and ship owners, operators, shipyards and suppliers need support to understand the technology in order to further adopt it. ”
There have been comments that BERG Propulsion’s new electric drive concept is reminiscent of the two-stroke engine that is considered the most efficient marine propulsion system – coupled directly to the propeller.
Accepting this analogy of “replacing two-stroke engines with electric engines”, he added: “We are having broader discussions on various marine applications, and electric drive solutions are perfect for cargo ships and fuel ships because these ships have very diverse operating models.” We also discussed with ferry operators who could benefit from this solution, where we would connect two motors in series on the same axis, each with a power of more than 15 megawatts. ”
It is believed that within five years, BERG Propulsion’s power solution will be one of the mainstream promotion options. “It’s an advanced solution, but we need to find ways to have a dialogue with shipowners and shipyards so that the vessel can design and meet the requirements. After all, since the frequency drivers associated with auxiliary systems are often supplied as a complete solution, the adoption of this system will be influenced by the traditional design cycle of marine components. ”