What’s an E-unit?
The ATE ‘E-units’ on the Adler Suprema are high-efficiency electric motors that can work as both a motor and a generator. As part of the hybrid system—along with the lithiumpolymer battery, Aradex inverters and TTControl automation—they are installed on the shaft between the main engines and the gearbox, separated with clutches, so they can be used as generators while the props are not rotating. The design also allows the Caterpillars to work in diesel mode with the E-units shut off, without loss of efficiency.
The E-unit system is key to the transition between propulsion sources: twin diesel, electric and hybrid, with hybrid meaning one Caterpillar engine running as propulsion on one shaft and one E-unit acting as a generator, creating sufficient electric energy at the second shaft to power the second motor. The mode can be manually selected, or the system can select the optimal mode depending on the power required and speed, allowing the operator to accelerate through the various modes by simply pushing the throttle forward. A display indicates which source is active. —A.P.