Table of contents:
- Fast payback
- Picture gallery
- A technology with a future
- Expensive battery operating costs
- Equip the engine especially for seafaring
Video: Environmentally Friendly And Efficient Thanks To The Parallel Hybrid Drive
Leroy-Somer and Control Techniques have been supplying various shipping and shipbuilding companies for many years. In collaboration with Mayday Electronics, they have now developed a high-performance drive system that, according to the manufacturer, is a leader in the field of hybrid technology. The system was developed for CNB PRO, a trademark of the French shipbuilding company Construction Navale Bordeaux (Bénéteau Group) and its customer Nave VA.
Nave VA specializes in trips to nature reserves. it is therefore important for the company to use environmentally friendly technologies. The company is therefore now using a new model of the CNB PRO 20 hybrid drive for its passenger ferries. If you want to maneuver at low speeds in ports or in nature reserves, the ferry switches to electric drive. "The silence is overwhelming," says Eric Brun from Mayday.
In contrast to the serial drive, the size of the parallel hybrid drive can be precisely tailored to the desired requirements. The electric motor in the ships of the Nave VA company can be set to an operating mode of 6 to 8 knots. This ensures maximum efficiency: at slow speeds, the electric motor runs in the optimal operating range. In addition, the drive is much lighter with the same range. Finally, the internal combustion engines can be switched off on board when the electric motors are running. “At low speeds, diesel drives are hardly an option. Then they are simply not efficient and tend to foul. The fact that the diesel engine can be switched off when the electric drive system is put into operationOf course, its lifespan is also extended. In some applications, the lifespan is even doubled,”explains Pierre Lompech from CNB PRO.
In the case of the Nave ferry, this means that the engine only needs to be replaced after sixteen years instead of eight years. In the present case, the replacement of the two diesel engines is just as expensive as the electric drive system. “If an electric drive system is used instead of the built-in internal combustion engines during turning and mooring maneuvers in ports and when traveling at low speed, the diesel engines no longer have to run at low power and are therefore almost always efficient. With partial load operation, a significant reduction in fuel consumption and maintenance costs can be achieved. 70 liters of fuel per diesel engine, ie 140 l per ship, can be saved per hour. If you consider that an electric drive, depending on the capacity of the batteries, between 350,000 and 400.000 euros and ship excursions are a seasonal business, it can be assumed that the investment in a hybrid drive will pay off in less than four seasons. In addition, the lifespan of the diesel drives increases and the maintenance intervals increase,”says Pierre Lompech. As is usual with passenger ferries, the electric drive has an emergency system.
A technology with a future
“Today, the use of an electric drive is mandatory in more and more locations, and not just in nature reserves. With this in mind, we are working on a hybrid system, namely a parallel hybrid system that is ideally suited for ships with a length of 30 meters. However, it can also be used in regular ferry services, on connections between two ports, in inland navigation or in pleasure boats,”explains Pierre Lompech.
The passenger ship, which was delivered to Nave VA, is equipped with two 800 PS engines, which allow a speed of 20 knots in diesel mode. The maximum speed for electrical operation is 8 knots. The batteries last for 6 to 8 hours at a cruising speed of 6 knots. The batteries can be recharged in a maximum of 6 hours via a three-phase power supply on the quay or via the on-board generator.
Brake motors in the high-performance design "Flexible Concept"
Expensive battery operating costs
“In the future, electric drives may be offered even more cost-effectively. The batteries take up a lot of space and are still quite expensive with an operating cost of around 1 euro per Wh. With an installed electrical output of 125 kWh, the costs for the batteries make up about half of the total costs for the drive system. The remaining costs arise from the mechanical drive system, the two motors and the gearbox. All drive parts are ideally suited for shipping. The engines and gearboxes are installed in the dry dock, the fastenings are made of stainless steel, and individual parts can often be protected from the harsh conditions in shipping by simple measures such as painting,”explains Eric Brun.
“Despite these enormous advantages, only a few parallel hybrid systems are currently in operation, particularly in France. In addition to the passenger ferries, smaller sports or leisure boats, super yachts and military ships are typical areas of application,”says Eric Brun.
New frequency converters for high speeds
Equip the engine especially for seafaring
Leroy-Somer and Control Techniques specialize worldwide in the production and delivery of drive solutions and offer numerous products that have been specially designed for use in shipping.
“We chose a Dyneo synchronous motor from the LSRPM series with permanent magnets and a speed range from 750 min –1 to 3000 min –1, because it was particularly impressive due to its high performance and compact design. We also looked at other compact motors, but these required separate cooling systems and this would have made installation difficult with the limited space available in the engine room. In addition, Leroy-Somer offered to equip the engine specifically for seafaring by installing the entire engine block in an aluminum housing that is ideally suited to these special environmental conditions,”added Eric Brun.
Compared to asynchronous motors, the synchronous motors should be significantly smaller and lighter. For the inverters of the Unidrive M series, Control Techniques guarantees lower energy consumption as well as increased reliability and flexibility. In this way, the total costs for installation and operation should be noticeably reduced. (sh)