Automotive supplier ZF has presented energy management software for commercial electric vehicles. The software manages not only the energy requirements of the driveline but also of auxiliary units such as the air compressor, steering pump and thermal management.
According to ZF, this integrative approach is intended to make electrically driven commercial vehicles more efficient with the energy management system (EMS). The energy consumption per kilometre is reduced, resulting in a corresponding gain in range or a reduction in battery costs.
When the vehicle starts, the EMS coordinates the correct start-up, availability and interaction of all components in the vehicle that are relevant for the energy flow. This ranges from the battery’s state of charge to the electric drive and all auxiliary units such as the compressor, DC/DC converter or heater.
If the battery charge level drops during a longer journey, the EMS can prioritise the energy demand of the auxiliary units in favour of the range. Since the EMS also makes use of the already well-known predictive function ePreVision, the compressor, for example, can be operated directly with the electricity from recuperation during a long downhill drive. In addition, the system plans for foreseeable recuperation phases during charging: if the first journey after the depot is a long downhill passage, the batteries will not be fully charged.
“With our system, we are targeting bus and truck manufacturers unable to develop their own EMS or want to use them differently,” says Winfried Gründler, responsible for the E-Mobility business unit in the Commercial Vehicle Technology division at ZF. “Fleet owners such as transport authorities also benefit when only one partner assumes overall responsibility for the energy management of a vehicle.”
ZF offers the EMS as an add-on to the electric drive systems for commercial vehicles that have already been successfully introduced in series production. No additional control units are necessary, as the control unit of the electric drive is used for the EMS. The EMS accesses the other units via CAN bus.
With reporting by Sebastian Schaal, Germany.