Belt-Driven Starter Alternator, Basic Function - GF15.40-P-1001A

Model all (CAR) 

Overview 

This document contains information on:

• General 
• Function 
  • Engine start/Automatic engine start/stop 
  • Alternator 
  • Recuperation 

General 

The belt-driven starter-alternator (RSG) combines the functions of the starter and the alternator into one system, thereby replacing the individual components used up till now. The starter-alternator contains a power electronics part via which the operating mode is set. Internal actuation of the power electronics determines how much electrical energy the starter-alternator generates or consumes.

Function 

Engine start/Automatic engine start/stop 

The belt-driven starter alternator replaces the conventional starter. The torque is transmitted via a poly-V-belt between the starter-alternator and the crankshaft.

Alternator 

The belt-driven starter alternator supplies energy to the 48 V battery or the high-voltage battery via the alternator function. The starter-alternator can supply energy to the connected on-board electrical system both when the vehicle is stationary and when driving. The possible operating mode as well as the charging torques to be provided are defined in characteristics maps and specified, depending on, among other things, speed, state of charge, torque request.

Recuperation 

In the case of braking applications, the belt-driven starter-alternator can recover energy and supply the 48 V battery or high-voltage battery with electrical energy.

Brake intentions are detected in combination with an electromechanical brake booster. Depending on the required brake force, either regenerative braking alone, or hydraulic braking can be used.