YANMAR Technical Review

Abstract

As the need to reduce greenhouse gas emissions becomes a priority, many governments have flagged electric transport as a part of the solution. Cars, scooters and bikes become increasingly electrified, and there has also been a spike in interest in another category of transport – boats. VETUS has introduced a completely plug and play electric propulsion package to provide boaters a unique experience and a full day on the water without any limitations.

1.Introduction

Yanmar company VETUS, one of the pioneers of electric propulsion, has developed its technology further with two advanced, modular E-DRIVE systems designed for water displacement and semi-displacement boats. The E-DRIVES are unique to the market due to their capability to provide maximum comfort with minimum energy consumption by combining high system efficiency with patented VETUS energy management and monitoring systems technology.

Using the same VETUS V-CAN bus communication system connectivity as the company’s proportional thrusters, all VETUS E-DRIVE motors can be combined with various control and monitoring options. This VETUS feature enables users to easily manage the decreasing remaining boating time when using high amounts of energy. In addition, advanced motor management and liquid cooling technology optimize motor power and battery range. Using the correctly specified battery pack, customers with VETUS E-DRIVES installed can therefore enjoy easy cruising and a full day on the water.

Developed with the future expansion of the range in mind, VETUS electric propulsion systems include several unique benefits, such as the patented Motor Controller, Active Electric Braking, Battery Protection Function, and Boosted Battery Charge Function, alongside other key accessories – all of which are designed for incorporation into upcoming VETUS motors.

The current E-DRIVE range consists of the E-LINE range, standard shaft-driven in-board diesel engine replacements, and the E-POD, designed for installation in the vessel’s stern. Both offer a user experience which replicates sailing with an internal combustion engine, but without the emissions and noise (Figure 1).

2.Product overview

2.1.The VETUS E-LINE and E-POD

a. The VETUS E-LINE inboard motor suits a range of boats, depending on required speed and range, covering sail, power and narrow boats of about 11 metres and above, and is designed to fit the existing propulsion foundation and propeller shaft installation. Featuring a compact design with motor controller and motor, the 48V E-LINE is available in three models with output power of 5 kW to 10 kW, with a peak input power up to 13.3 kW. Re-powering and connecting to an existing propeller shaft are easy with adjustable Swap & Go mounting brackets (Figure 2).

b. The VETUS E-POD is ideal as a space-saving refit solution for sailboats with a sail drive, as well as for new build sail and motor boats, and is the most efficient VETUS E-DRIVE system. Combining the motor, suspension, cooling, gearbox, clutch, propeller shaft and propeller into one complete system, the E-POD has no rotating or vibrating parts inside the boat and no shaft or shaft bearings. The specially designed enclosed propeller is the rotor of the energy efficient permanent magnet brushless motor drive. It minimizes cavitation and improves the effective thrust to increase efficiency, ensuring comfortable cruising at low speeds (Figure 3).

2.2.E-DRIVE ADVANCED FEATURES

a. Energy Management Technology: Key to the success of the VETUS E-DRIVES, the VETUS energy management technology ensures energy levels are easy to gauge on the monitoring panels. The E-DRIVE motors work with the modular digital CAN-bus communication system VETUS V-CAN and the NMEA200 connected solution, enabling all motors to be combined with various control and monitoring options. By installing the CANNS500 battery shunt, the user can connect any WiFi or NMEA2000 MFD to view the information on remaining battery charge and runtime. With a CANNME7 MFD, along with the CANNS500 battery monitoring shunt, the user can project the remaining range circle on an installed map (optional) (Figure 4). The projected circle, as well as displayed remaining time, are updated based on the power consumption at that time, plus speed for the circle distance. When using high amounts of energy in a short time, the CANNME7 display will show a decreasing remaining boating time. Reducing consumption leads to an increase in remaining time, while increasing consumption suddenly will lead to a decrease in remaining time.

b. Active Electric Braking: The VETUS E-DRIVE systems accelerate more powerfully and faster than a diesel engine. With no gearbox and clutch required, when reversing the propeller, the complete high speed electric motor must immediately come to a full stop and then rotate in the opposite direction. To enable a quick reverse power manoeuvre, the VETUS E-DRIVES are the only electric propulsion solutions with ‘Active Motor Braking’, providing optimum control of the boat, with almost no delay, direct movement and total control. The high torque of the electric motor is used to change the direction of rotation quickly and actively. It is possible to stop the boat within one boat length if necessary.

c. Patented Motor Controller VETUS (MCV): All VETUS E-DRIVE motors are equipped with the MCV with boosted charge function (Figure 5).

d. Battery Protection function: To prevent damage to the batteries, the MCV of the VETUS E-DRIVES actively monitors the battery pack state of charge by verifying voltage and current draw. The Battery Protection function ensures that the battery pack is not unnecessarily damaged, and the service life cycle of the batteries is guarded for the present and future boating seasons.

e. Boosted Battery Charge function: Using the patented Boosted Battery Charge function, a 24 VDC charger can be used to charge up the required 48 VDC battery pack for propulsion (Figure 6). This is an economic advantage as the 24 VDC battery charger is more common and allows the boat builder an easy way to provide a low voltage 24 VDC electric board network.

3. Discussion

While developing our electric propulsion solution we noticed that there is a benefit with our solution where the environment is the definite winner - we have realized potentially massive savings due to a much better insight in energy consumption related to an individual boater’s behaviour.
The VETUS breakthrough innovation is giving the boater direct insight on power consumption by combining measured speed, motor rev/min and battery data.
By showing the boater the increasing/decreasing range circle around the boat (see Figure 4) a direct relationship is underlined between the way the boat is handled and the range that is left.
When considering the important principle of the boat hull speed - the maximal speed of that specific boat - there is an immediate benefit (longer range) shown on screen when the ideal throttle position is found in relation to speed. Our test groups have shown that this leads to immediate and significant energy savings when compared to “traditional” boating.
Due to this study, we noticed that in displacement combustion engine boats there is a general waste of energy that is not noticed because of the lack of detailed real-time information and consequential visualization.
Captains worldwide are wasting energy without knowing it. This is mostly because of the abundance of energy available that this happens without direct consequences - except for the environment of course!

4. Conclusion

The VETUS mission in the field of electric boating is to provide compact, complete, highly efficient, plug and play systems for smooth and silent sailing with no emissions.

For customers using both the E-LINE in-line propeller shaft solutions and the innovative compact E-POD system, the key benefit is the energy management technology while enables the user to easily manage power consumption and remaining boating time, depending on the position of the throttle handle. With the efficient motor at the heart of the systems connected to the NMEA2000 solutions via the modular digital CAN-bus communication system VETUS V-CAN, the user has crucial visibility of remaining battery charge and runtime when installing the CANNS500 battery monitoring shunt and the CANNME7 MFD.

The additional VETUS features of the patented Motor Controller, Active Electric Braking, Battery Protection Function, Boosted Battery Charge Function and liquid cooling enable maximum power and range to be achieved for a long day on the water with peace of mind, now and in the future.