The fully electric BW 177 DH e single-drum roller, jointly developed by SUNCAR and BOMAG and weighing 7 tonnes, marks a significant advance in sustainable and efficient compaction machine technology. The development project covered the entire electrification process—from selecting the main components through to commissioning and the technical documentation of the first functional prototypes.
- Electrification of the BW 177 DH e: comprehensive conversion to electric drive, with only the steering and parking brake remaining hydraulic.
- Four electric motors: one motor each for the front and rear axles, plus one each for the vibration function and the auxiliary-drive hydraulic pump.
- Efficiency gains through recuperation when driving downhill and braking result in major energy savings.
- High-performance charging system: CCS2 standard with AC charging up to 22 kW and DC charging up to 80 kW peak power (approx. 1 hour charging time).
- Intelligent thermal management: battery and cab with active temperature control, heat pump and heater for optimal operating conditions.
Results
The BOMAG BW 177 DH e base machine, which served as the platform for the requirements of the electric machine, was converted to an electric drive for this project. Based on typical operating scenarios of the base machine, BOMAG defined requirements, for example for operating time and charging time, as well as the thermal management of the electrified machine, within a comprehensive electrification concept. Together with SUNCAR, this concept, the components—including their placement—and the design were evaluated, and the sizing and development of the electronics were planned. In addition, the complete software for the electric machine and the control of the traction drive was developed.
The electrification concept is based on a very extensive conversion—of the original hydraulic system, only the steering and the parking brake were retained.
The electric single-drum roller is equipped with a total of 4 electric motors: the traction drive was implemented fully electrically, with one electric motor each for the front and rear axles. This makes it possible to recuperate energy during braking and downhill driving and feed it back into the battery. The vibration function of the single-drum roller was also electrified.
The CCS2-standard charging system supports AC charging up to 22 kW as well as DC charging with a peak power of around 80 kW and a continuous power of around 40 kW, depending on the exact charging current curve (i.e., temperature and state of charge) of the high-voltage battery. The high-voltage battery consists of two modules with a gross capacity of 39 kWh each.
Battery temperature control is provided via an active circuit with a heat pump and a heater, while the electronics circuit is passively controlled via a separate radiator. During operation, the battery is kept within the optimal temperature range. If the temperature differential within the battery becomes too large, a circulation pump is activated to ensure temperature balance between the battery cells.
SUNCAR’s INSIGHT remote system enables the acquisition and transmission of measured values, events and parameters, as well as performing over-the-air software updates. The INTERFUSION high-voltage distribution system connects the machine’s main components—battery, charger, inverter, motor and the fast-charging system. In this combination of the FUSION800M and INTERFLOW500 products, all positive terminals are protected, and fast charging is equipped with HV relays as well as current and voltage measurement.
Through the close collaboration between SUNCAR and BOMAG, the BW 177 DH e was created as an innovative, fully electric compaction machine that combines maximum efficiency, sustainability and state-of-the-art technology.
More info: https://www.bomag.com/de-de/technologien/uebersicht/e-performance/
