Economical and powerful: diesel-electric drives
Besides fully electric solutions, diesel-electric hybrid drives are the technology of choice when it comes to finding an economical, environmentally friendly alternative to equipping ships with state-of-the-art technology.
Alternative planning pays: For example, ferries benefit from improved maneuverability, yachts from lower noise emissions and work boats from the higher performance. Operators can look forward to lower fuel costs and the environment benefits from the lower emissions.
Baumüller is a partner for shipyards, system integrators and ship owners, as well as being an independent supplier of complete systems.
Greater efficiency through electrical operation with diesel generators
With a diesel-electric hybrid drive, the ship’s propellers are powered electrically by converter-fed synchronous motors which receive their energy from diesel generators. Many benefits make the combination of diesel engine and electric motor particularly attractive for the shipping industry. Along with a significant reduction in fuel consumption in moving bodies of water of up to 28%, the system also reduces noise and vibrations.
Another benefit is the improvement in the diesel motor’s overall efficiency. Ships that maneuver precisely on the open sea or have to remain within a set application location, for example, only require minimal output. With a pure diesel drive, the speed in these cases is massively reduced compared to the previous, faster moving journey. This means the motor is not running inside of its ideal efficiency range. When an electric drive is used in these situations, by contrast, the frequency converter directly controls the propeller speed via the synchronous motor, which allows it to run much more slowly. Since electric motors achieve high efficiency even at low speeds, electric operation saves fuel.
Parallel hybrid and serial hybrid: Drive systems with optimum efficiency
In principle, there are two options for ship drives when designing a diesel-electric drive system. One is the parallel hybrid, in which the diesel and electric motors are synchronized to achieve full power; this is seldom used. The state-of-the-art approach is the series hybrid, in which the electric motor has the sole responsibility for driving the propellers. In this solution, the combustion motor drives the generator, which supplies the electric power. It can be operated with excellent efficiency thanks to the fact that it is completely decoupled from the drive system. In addition, the series model offers the option of operating the ship completely electrically and thus with zero emissions, which is particularly beneficial for harbor navigation. With a parallel hybrid drive, this would only be possible with an additional diesel generator and all the associated extra costs, e.g. for particulate filters.
Example of the structure of a diesel-electric system that lowers costs and reduces emissions
Hybrid marine power from Baumüller
Diesel-electric: the advantages
Many benefits make the combination of diesel engine and electric motor particularly attractive for ship drives. Along with a significant reduction in fuel consumption, this system also reduces noise and vibrations.
The improvement in overall efficiency through an output reduction feature on the diesel engine, ensuring travel within the optimal speed range, saves fuel. But electrical operation offers yet another advantage: enhanced maneuverability, which is a consequence of the electric motor’s constant torque. Full torque is available even at low speeds, which is a major advantage when maneuvering in harbors or when mooring or setting sail.
System expertise
Baumüller primarily uses synchronous motors in its drive systems for ships. These boast a small size, a comparatively low weight and, above all, a high degree of efficiency. These advantages make them particularly well-suited for mobile use.
The DST2 high-torque motor is used as an electric propulsion motor in a diesel-electric drive and is fed by a diesel engine
Baumüller’s system engineering experts create complete solutions for diesel-electric drive systems
In addition to its component expertise, Baumüller is also a system partner. In collaboration with companies such as battery manufacturers, the system engineering experts from Baumüller create complete solutions for drive and automation systems and fit out ships using in-house torque motors, converters and control units, among other devices. The Baumüller complete solution includes electric motors, converters, scalable lithium-ion batteries with energy management systems, control cabinets, thruster and propeller control units.