MTU hybrid propulsion

As part of its increasing specialised portfolio of propulsion systems German diesel engine manufacturer MTU is now offering complete system integration for its E-Drive solutions. Aimed mainly at the patrol boat, workboat and superyacht markets, MTU claims that its hybrid propulsion systems give greater cost-effectiveness and comfort as lower fuel consumption.

In addition there are reduced noise and vibration levels when the electric drive is being used. The drive systems, which are customised by MTU to meet the client's specific needs, are based on the powerful, low-emission Series 2000, 4000, 1163 and 8000 diesel engines from the MTU range with power ratings up to 10,000 kW.

MTU has extended its propulsion portfolio by introducing these highly integrated E-Drive systems. They comprise propulsion and on-board power generation by propulsion diesel engines, diesel-driven generators, and additional electric motors for propulsion and power generation as well as energy storage. These comprehensive propulsion packages are claimed to offer benefits for shipyards in terms of integration costs and innovative products as well as advantages for operators thanks to minimal emissions, low life-cycle costs and outstanding propulsion performance. Numerous arrangements of the individual components are possible.

The E-Drive solutions are particularly suited, for example, for patrol vessels which can have widely fluctuating load profiles. Vessel operators stand to benefit from the key advantages of quiet and emission-free energy for on-board or propulsion power for given periods of time as well as from increased trip range thanks to enhanced fuel economy. For tug operators, E-Drive solutions mean increased bollard pull power and the prospect of extending main engine TBOs by switching to genset power or combined operation.

Recently MTU has partnered with German electric propulsion specialist Akasol to develop and deliver battery systems for the hybrid and E-Drive propulsion systems of MTU in the marine applications sector. Akasol develops and produces innovative lithium-ion battery systems for high performance applications.

A spokesperson from MTU said, "The integration of the various components into an E-Drive system requires a thorough investigation of the applications and customer demands to yield a powerful and efficient solution. This integration process of MTU called MELT and includes the optimization of all four tasks:-

Mechanical, i.e. Space Requirements, Energy Transmission, Vibrations, Environment, Noise and Comfort.

Electrical, i.e. Stability, Availability , Space & Thermal Requirements, Electromagnetic Compatibility (EMC)

Logical, i.e. Power- & Energy Management, System Architecture, Safety, Homologation

Thermal, i.e. Durability, Efficiency, Space Requirements, Complexity & Pinch Points

"The selection of the appropriate components, such as e-machines (motor/generator), power electronics (propulsion, hotel load, shore connection, battery charging/discharging), DC- or AC-Link, batteries with their specific characteristics and the dimensioning in power and energy capabilities is the foundation of MTU's efforts in E-Drive systems. Comprehensive simulation capabilities guarantee an efficient and successful MELT process combined with the advantage of a 'One-Stop-Shop' which ends up in as low risk solution for our customers."

One of the most important decisions which have to be made within the MELT process concerns the energy storage systems. "It is of high importance to investigate project specific the need and size for an electric energy storage system which is strongly depending on the operating profile. In the case of installing batteries it is essential to size them according the requirements to avoid excessive efforts with only minor improvements."

MTU claims that it provides comprehensive simulation techniques to match the requirements stipulated by the operator with the system and component characteristics. Especially for the energy storage requirements MTU has developed a technology for its own marine application designed battery systems. This qualified battery technology incorporates compact and powerful design, high power and energy density, water-cooling, and reliable and certified safety.