MAN hybridizes marine engines

The components in the MAN Smart Hybrid Experience for marine engines.

The MAN Smart Hybrid Experience is composed of a diesel engine, a clutch and an electric motor/generator unit. The latter is available in two sizes with nominal power of 184 and 368 kW (250 and 500 hp)  respectively and an efficiency rate up to 96%. The permanent magnet synchronous motors/generators have a length of 160 mm (6.3 in) in the 184 kW (250 hp) version and 320 mm (12.6 in) for the unit with 368 kW (500 hp) power output, while the diameter is 560 mm (22 in).

The electric machine is mounted on the diesel engine before the marine gearbox and can be decoupled from the diesel unit by an electromagnetic clutch, which allows to change propulsion mode without interruption in propulsion power.

The MAN Smart Hybrid Experience is available for all MAN marine engines series D2862 (12-cylinder vee configuration), D2868 (eight-cylinder vee configuration) and D2676 (inline six-cylinder). For all these engines, the installation of the hybrid system allows to reach a hybridization degree of up to 56% of the diesel power output: “For example a six-cylinder inline diesel with 290 kW (394 hp) power output can be combined with the 184 kW (250 hp) electric motor/generator unit to reach a combined output of 474 kW (644 hp),” explained Reiner Roessner, MAN Engines’ head of Sales.

The MAN Smart Hybrid Experience for marine engines in boost mode

With the MAN Smart Hybrid Experience the company will be able to supply a complete hybrid system from a single source, insuring the best combination of complex components such as electric motors, batteries, power electronics, and voltage management for every single marine application. Testing on benches as well as comprehensive tests on the field are also a key step in the development of new MAN components and make sure that the company delivers its usual high-quality standards even with completely new-developed products.

The power sources of the hybrid system are the main diesel engines, the onboard gen-sets, and high-voltage batteries. The latter can be recharged via the Plug-in-Hybrid with an integrated land connection to be used when docked, or during boat operation through the diesel engines or on-board gen-sets. Even solar cells can be an option to be integrated in the power management system.

For the high-voltage batteries, MAN has chosen components from different manufacturers that operate at voltages over 600 V, which means the batteries can be flexibly operated at voltages between 500 and 750 V. Roessner explained that sourcing for batteries from external suppliers is a first step; in the future, plans are to produce batteries in-house profiting of the experience within the MAN Group on batteries for commercial vehicles. The MAN plant in Nurnberg, Germany, has already been partially transformed to host battery production for on-highway vehicles and also incorporates a new, dedicated test area.

Roessner added that it has always been MAN’s aim to develop standard drivelines with its diesel engines and the same is true for new hybrid drivelines too. In fact, while the MAN hybrid solution is flexible, scalable and allows to deliver the degree of hybridization that is better suited to the specific customer, the system utilizes standard series-production components and is available for any gearbox configuration, such as V-drive, IV-drive, parallel gearboxes, and Down Angle.

The MAN Smart Hybrid Experience for marine engines: diesel-electric mode

The MAN Smart Hybrid Experience can be operated with different modes:

- Zero-Emissions, with no exhaust emissions and super-quiet operation.

- Diesel-Electric, with propulsion and on-board electricity delivered by the gen-sets with the support of the batteries upon demand.

- Cross-Over: when the boat has a twin-engine propulsion arrangement, the cross-over option allows to operate each propulsion train in a different mode.

- Hotel, when all power is derived from the batteries; this mode allows for a long use of the batteries with no need to start the diesel engines.

- Boost, when diesel engines and the electric motor act together and complement each other to reach the higher power output. For example, a 12-cylinder engine operating together with the electric motor, can reach a power output comparable to that a 16-cylinder engine.

- Diesel: the classic diesel operation that can provide power for propulsion while the electric motor runs without producing energy. In this mode, diesel operation can also provide the electricity needed to recharge the batteries without using the onboard gen-sets.

The MAN Smart Hybrid Experience will be available on the global market starting mid-September 2021, when the first commercial installation is expected to be released. Classification with the major marine societies in is progress.

The company expects various marine segments to be interested to the hybrid system: “Applications such as yachts will look for hybrid solutions mainly for the comfort aspect, while super-fast boats will be attracted by the performance. Passenger transport boats will also be interested, looking mostly at the environmental aspect and the capability of entering ports and environmental-sensitive areas in full-electric mode,” concluded Roessner.

Read the full interview with MAN Engines’ Reiner Roessner in upcoming issues of Diesel Progress and Diesel Progress International. If you are not a subscriber yet, register to receive your free copy of the magazines here: Diesel Progress - Diesel Progress International.