more work on documentation

Documentation/User Manual/1-user-interface/F_VEH-Editor.md

@@ -147,6 +147,7 @@ The *Efficiency EM to Drivetrain* can be used to consider the efficiency of a tr
 
 For the electric energy storage multiple battery packs can be configured and the initial state of charge can be defined.
 
+The maximum power of a hybrid drivetrain can be limited to a certain power. This limit has to be at least the maximum power of the combustion engine.
 
 ###Torque Limits
 

Documentation/User Manual/3-simulation-models/Electric_Motor.md

 ##Electric Motor
+
+The electric motor is modeled by basically 4 map files:
+ - Maximum drive torque over motor speed
+ - Maximum generation torque over motor speed
+ - Drag curve (i.e., the motor is not energized) over motor speed
+ - Electric power map
+
+The first two curves are read from a single .vemp file (see [Electric Motor Max Torque File (.vemp)](#electric-motor-max-torque-file-.vemp)). The drag curve is provided in a .vemd file (see [Electric Motor Drag Curve File (.vemd)](#electric-motor-drag-curve-file-.vemd)) and the electric power map in a .vemo file (see [Electric Motor Map (.vemo)](#electric-motor-map-.vemo)).
+
+The convention for all input files is that positive torque values drive the vehicle while negative torque values apply additional drag and generate electric power.