As the first all-electric sports car for the water, the Q2 sports boat is celebrated by the Slovenian manufacturer Quadrofoil. The sportive-nautical revolution is also made possible by state-of-the-art measuring technologies: the Slovenian pleasure boat manufacturer relies on continuous and comprehensive measuring procedures including tests by Dewesoft.

100 kilograms light, all-electric and speeds of up to 40 km / h: The Slovenian high-tech company Quadrofoil wants to revolutionize the nautical science with what is said to be the first all-electric "water supercar". The technical ingredients for this project are there: Because from a speed of twelve km/h, the buoyancy of the four wings of the supersport boat is sufficient to lift the hull out of the water, the draft is reduced to 15 centimetres - and the Quadrofoil becomes even more agile. In other words, while ordinary boats use most of the energy in the hull to displace the water, the Qudrofoil lifts the hull so that only the air resistance on the foil, instead of the entire resistance, has to be overcome.

Both with the 4.5 kW variant and the 5.5 kW engine, extremely quiet driving experiences are possible – and the boats are charged within three to four hours. An intuitive battery management system (BMS) monitors the performance of each cell. Due to the rapidly decreasing water resistance, the power output of the engine can be throttled while maintaining its high speed. This challenge required adaptation and validation of the powertrain.

Dewesoft measurement technology is on board

Measurement technologies from Dewesoft play a role here: we have set up both the measurement of the DC and AC components of the Q2 powertrain to measure the efficiency and quality of the power conversion of the motor power supply. In addition, the vessel's position, velocity, acceleration, and attitude were measured using an inertial measurement unit (IMU), an electronic device that measures and reports the specific force and angular velocity of a body. Two cameras were used to define how much water the hydrofoils displaced during operation. The following devices were used for the measurement: a power supply unit (SIRIUSi-PWR-MCTS2), a data acquisition unit (SIRIUSi-HS-4xHV-4xLV), a battery pack (DS-BP2i), four current clamps (DS-CLAMP-500DCS), an inertial measurement unit (DS-IMU2), two cameras and a laptop with Dewesoft X3. Using these innovative Dewesoft products, we were able to collect detailed data on the relationship between power requirements and vessel behaviour.

The process

Specifically, the procedure was as follows: First, the current clamps were mounted to the power lines from the battery to the inverter - and also on the AC side to the motor. Challenging, since the space under the engine cover is very tight, the cover had to be completely removed and everything covered up with a stretch film to protect the electronics from water. Next, the IMU, the electronic device, was mounted as close as possible to the center of the vessel and the two associated GPS antennas - at the rear and front of the vessel. A camera was placed on the side of the vehicle looking at the left rear foil, and the second was mounted high above the ship on a beam and allowed a view of the front of the vehicle. Battery pack, power supply for the current clamps, SIRIUS HS and a laptop were placed in the back seat, connected to each other and packed in a plastic bag to protect against water. Finally, the Quadrofoil team put the ship into the water: the first test runs were completed and the slides set up in various positions.

The data evaluation

The data collected showed that the vessel had to reach about ten to twelve km / h to push the hull out of the water - about 13 to 14 kW of power is needed. However, immediately thereafter, the power requirement drops to about eight to ten kW for cruising speeds between 24 and 30 km / h. The efficiency of the inverter is between 95 and 99 percent throughout the measurement. A strong indication that the inverter is really efficient, which in turn means that more energy is available for the drive and that the cooling requirement is low, allowing for a more compact and cost-effective cooling solution.

Find out more in the Case Study