BOMAG Compactor

The all-electric BW 177 DH e compactor weighing 7 tons, developed jointly by SUNCAR and BOMAG, marks a significant advance in sustainable and efficient compaction machine technology. The development project encompassed the entire electrification process - from the selection of the main components to the commissioning and technical documentation of the first functional models.

• 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, as well as one each for the vibration function and the auxiliary drive hydraulic pump.
• Increased efficiency through recuperation when driving downhill and braking leads to major energy savings.
• Powerful 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 cabin with active temperature control, heat pump and heater for optimum operating conditions.

Results

The basic machine BOMAG BW 177 DH e, which served as the basis for the requirements of the electric machine, was converted to an electric drive for this project. Based on typical operating scenarios of the basic machine, BOMAG defined requirements for, for example, the operating time and charging time, as well as the thermal management of the electrified machine in a comprehensive electrification concept. Together with SUNCAR, this concept, the components, including their placement and design, were evaluated and the design and development of the electronics was planned. The complete software for the electric machine and the control of the drive was also developed.

The electrification concept is based on a very far-reaching conversion - only the steering and the parking brake were retained from the original hydraulic system.
The electric compactor is equipped with a total of 4 electric motors: The travel drive has been implemented completely electrically, with one electric motor each for the front and rear axles. This enables the energy to be recuperated when braking and driving downhill and fed back into the battery. The vibration function of the compactor has also been electrified.

The CCS2 standard charging system supports AC charging up to 22 kW as well as DC charging with a peak output of around 80 kW and a continuous output of around 40 kW, depending on the exact charging current curve (i.e. temperature and charge level) of the high-voltage battery. The high-voltage battery consists of two modules, each with a gross capacity of 39 kWh.

The battery temperature is controlled via an active circuit with a heat pump and a heater, while the electronics circuit is controlled passively via a separate cooler. During operation, the battery is kept within the optimum temperature range. If the temperature difference within the battery is too great, a circulation pump is activated to ensure the temperature balance between the battery cells.

The INSIGHT remote system from SUNCAR enables measured values, events and parameters to be recorded and transmitted, and software updates to be carried out over the air. The INTERFUSION high-voltage distribution system connects the main components battery, charger, inverter, motor and the machine's rapid charging system. With this combination of the FUSION800M and INTERFLOW500 products, all positive connections are fused and the fast charging system is equipped with HV relays and current and voltage measurement.

The close cooperation between SUNCAR and BOMAG has resulted in the BW 177 DH e, an innovative, fully electric compactor that combines maximum efficiency, sustainability and state-of-the-art technology.

More about e-PERFORMANCE at BOMAG