An energy management system (EMS) from automotive supplier ZF Friedrichshafen, implemented entirely in software, orchestrates the entire energy flow in electrified commercial vehicles. The system occupies a central position in the electric or electrified driveline. It not only coordinates the energy consumption of the electric traction system, but also includes all auxiliary units such as air compressor, steering pump and thermal management in the energy budget. This integrative approach makes electrically driven commercial vehicles more efficient: The energy consumption per kilometre is reduced, which should result in a corresponding gain in range or a reduction in battery costs. In addition, there are further benefits for maintenance and diagnostics as well as a positive influence on the battery's service life. The manufacturer offers the EMS as an add-on to the electric drive systems for commercial vehicles already introduced in series production.
From the system start, the EMS coordinates the correct start-up sequence and manages 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.
The ZF software ePreVision also works together with the EMS - it uses GPS data on the course of the road to further reduce the vehicle's energy consumption by means of predictive driving strategies. For example, the compressor can operate directly with electricity from recuperation during foreseeable, longer downhill journeys. On the other hand, the EMS also takes over the charging management in the depot, where the anticipatory functions also have advantages. If the first journey after the depot is a long downhill section, the batteries are not fully charged; the foreseeable recuperation phase directly after the start of the journey is already planned for during charging.
If the state of charge of the battery decreases during