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Energy management, function - GF54.10-P-0003RF

MODEL 205, 253 

Fig 1: Energy Management Block Diagram
G10133626Courtesy of MERCEDES-BENZ USA

IMPORTANT MODEL 205

with CODE U98 (LITHIUM-IONEN-STARTERBATTERIE (LISB))

An electronics system which performs the tasks of the battery sensor is integrated in the on-board electrical system battery.

Function requirements, general 

Energy management, general 

Energy management manages the provision (supply) and consumption (management) of electrical energy with the aim of ensuring mobility and a stable supply of all electrical consumers.

IMPORTANT Energy management specifies the 12 V on-board electrical system only. The correlation between the high-voltage and 12 V on-board electrical system is also described for hybrid vehicles (model 205.012/047/147/212/247).

The following components are involved in energy management:

Power electronics control unit (model 205.012/047/147/212/247) (energy transfer from high-voltage on-board electrical system for vehicle operation, energy transfer from 12 V on-board electrical system for charging the high-voltage battery)

Model 205.012/047/147/212/247: 

Because of the drive technology involved, hybrid vehicles are equipped with a high-voltage on-board electrical system.

Apart from the energy flows in the high-voltage on-board electrical system, the energy management module in the CDI control unit or ME-SFI control unit additionally controls the voltage conversion and energy exchange from and to the 12 V on-board electrical system.

For this purpose, the CDI control unit or the ME-SFI control unit communicates with the power electronics control unit via the drive train CAN, powertrain control unit and hybrid CAN and with the alternator via the drivetrain LIN. The 12 V on-board electrical system is supplied with energy primarily from the high-voltage on-board electrical system ("buck mode"). When the engine is off or in boost mode, the 12 V on-board electrical system is supplied with energy stored in the high-voltage battery and, when the vehicle is in operation, with energy generated by the electrical machine. If the energy made available by the power electronics control unit does not meet the existing energy requirements, the alternator will be switched on.

IMPORTANT When outside temperatures are extremely low, the 12 V on-board electrical system is supplied with energy from the high-voltage on-board electrical system in order to safeguard the engine's starting capability ("boost mode").

The following components are involved in the high-voltage energy management:

Transport mode: 

The transport mode is activated in the production plant at the end of the production process, and it sets the overall vehicle into a defined special condition.

With targeted interventions in individual electronics systems the following is achieved:

The transport mode remains active on its way from the production plant to the dealers and company-owned sales and service outlets around the world up to the so-called delivery inspection and the final handover to the end customers.

IMPORTANT The transport mode is automatically deactivated from a total distance traveled of more than 350 km whereupon it cannot be activated again. Up to this limit, the transport mode can be deactivated using the diagnosis tester or key combinations at any give time and activated with the diagnosis tester again. The fault memory is not actively deleted when the key combination is used for deactivation. This means that the "Transport mode active" entry remains stored. This must be deleted using the diagnosis tester when the vehicle is inspected for the first time.

To support the processes in Sales and Logistics, the vehicle's currently possible residual service life and, if necessary, appropriate care instructions for the on-board electrical system battery are shown on the multifunction display of the instrument cluster when the transport mode is active.

The energy management system's continuously determined condition of the on-board electrical system battery is rendered fully transparent at any given time without the use of any additional measuring instruments during the vehicle delivery period. This display provides the operating personnel with specific instructions on what to do to guarantee a high delivery quality with regard to the on-board electrical system battery.

The individual transport mode functionalities are split up for numerous individual systems. The core here is the central control of the transport mode by the energy management system. According to the energy management specifications, targeted interventions (function restrictions and changes) are carried out in individual electronics systems.

The following function limits or modifications are implemented during the transport mode:

The following tasks are carried out by the energy management system:

Major assembly coordinator: 

The major assembly coordinator is integrated into the CDI control unit or the ME-SFI control unit and forms the interface between the energy management system and the alternator. The CDI control unit or the ME-SFI control unit communicates with the alternator over the drive train LIN. The major assembly coordinator regulates the alternator's power output to match the energy management system specifications, taking engine load into consideration.

The recording and evaluation of the relevant variables for this are conducted by the following components:

Energy management contains the following functions, which are described in separate documents:

IMPORTANT The engine start/stop function is considered from the point of view of energy management.

  Engine on energy management, function   GF54.10-P-1060RF 
  Engine off energy management, function   GF54.10-P-1050RF 
  ECO start/stop function energy management, function   GF54.10-P-1040RF 
  DC/AC converter function MODEL 205, 253
with CODE U67 (230 V socket in interior compartment)		 GF54.10-P-2005RF 
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