Danfoss Scotland, part of hydraulics and electric powertrain systems supplier Danfoss Power Solutions, has announced the results of its Dextreme Max system validation in a 30-ton battery-electric excavator. The company demonstrated that its Dextreme digital hydraulic architecture reduced excavator power consumption by 35% across a representative duty-cycle mix, corresponding to 53% longer runtime on a charge.

Danfoss’s Dextreme Max system is designed to cut excavator energy consumption by reducing energy losses and recovering energy that would otherwise be wasted. The system’s integral component is the DDP1X0D Digital Displacement hydraulic pump/motor.

In 2023, Danfoss received a grant from the UK’s Department for Energy Security & Net Zero to develop and validate the Dextreme Max system. The grant represented approximately 65% of eligible project costs, and Danfoss provided the remaining funding.

Danfoss selected a Develon DX300LC-7 crawler excavator for the project. Dutch yellow machine manufacturer Staad replaced the excavator’s diesel engine with an electric drivetrain consisting of a Danfoss Editron EM-PMI375 permanent magnet synchronous motor, EC-C1200 inverter and MC050 motor controller, plus three 140 kWh battery packs.

Danfoss engineers replaced the excavator’s conventional swashplate hydraulic pump with the DDP180D pump/motor. The excavator’s four primary services—boom, arm, bucket and swing—are supplied through 10 individually controllable outlets on the pump. These outlets are dynamically grouped through a ganging block, a digital distributor that reallocates capacity to the service requiring it. A dedicated valve operating as a hydraulic H-bridge was developed and applied to the boom function to allow independent metering, providing anti-cavitation, pressure amplification and energy recovery during overrunning motions.

To compare system performance before and after conversion, the company carried out multiple tests, including JCMAS air grading and JCMAS air dig and dump (equivalent to ISO/AWI TS 11152-2). Compared with the baseline electric excavator, the Dextreme Max system reduced battery energy use by 49.2% in air grading and 31% in air dig and dump, with negligible impact on cycle time. Assuming a duty cycle of 30% grading and 70% digging, Dextreme Max would reduce battery power consumption by 35% without significantly affecting work rate. This would result in 53% longer operating hours with the same battery capacity as the baseline machine, or similar runtime as the baseline with two battery packs instead of three.

“The results of this testing highlight the potential of digital hydraulic architectures to overcome the obstacles in heavy-duty machinery electrification,” said Alasdair Robertson, Senior Director, Digital Displacement, Danfoss Power Solutions. “Electric excavators offer excellent responsiveness, smooth control, a quiet cab environment and zero-emission operation. With Dextreme Max, they can also deliver the runtime, productivity and total cost of ownership advantages required for wider adoption. We are encouraged by these results, but there is more work to do. Further gains are possible, and we will continue optimizing the system to maximize the energy savings and value for our customers.”

Source: Danfoss