الفهرس 
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Abstract
This research work presents a new driving system for electric
vehicles which are essential to be used nowadays for free environmental
pollution. The system is composed of two identical three-phase wound
rotor induction motors. Their stator windings are connected in series to a
common voltage source, while the windings of each rotor individually
short circuited through controllable resistors. These resistors are not only
used for starting but also for speed t.outrol of both motors such that
different speed ratios between the two motors call be controlled. The
speed ratios are used to represent the rectilinear and curvilinear motion
conditions of the vehicle. The mechanical technique used for inserting
these resistors into the rotor circuits is also introduced.
The equivalent circuit parameters of the two motors are measured in
the laboratory and modified by a computer programme to suit the normal
and abnormal operating conditions of the motors. This is done because of
the series connection of the two stator windings, which leads to different
magnetic and electric loading of the two motors, especially if they work at
different speeds. Further, the research introduces the way of choosing tp;e
suitable value of the common voltage source to avoid overheating of either
of the two motors. This is because operating the two motors from a
common source of double of the rated value of each motor results in
overheating of the lower speed motor.