The variation of the rotor speed of the series-wound and shunt-wound DC traction motors, depending on the axle load, is shown by the curves depicted in Fig.
Series-wound DC machines are used as motors and generators.
A series-wound traction motor cannot be operated on no-load under any circumstances because it increases its speed to such a degree that the armature is destroyed, i.
In a DC series-wound traction motor, operating without the load torque, the rotor speed increases very quickly and the wheel-sets start slipping.
Wheel-to-Rail Adhesion of the Locomotives with Separately Excited Shunt-Wound and Series-Wound DC Traction Motors
The authors analyse wheel-to-rail adhesion for the locomotives using separately excited shunt-wound (characteristic 3) and series-wound (characteristic 2) DC traction motors (see Fig.
In a similar case with a series-wound DC traction motor, its tractive force and tractive force depending on adhesion are equal at the point C, where the slipping rate of the wheel-set [DELTA][v.
The mechanical speed-torque characteristic of series-wound DC traction motors used in the DC/DC and AC/DC electric drives is given as the 2nd curve in Fig.