The double field revolving theory of single phase induction motor is proposed to explain this problem of no torque developed at starting and yet torque once rotated.
The Double Field Revolving Theory proposes that the universe operates through the interaction of two primary revolving fields: the Field of Matter and the Field of Energy.
It discusses the double field revolving theory, which represents an alternating magnetic field as the sum of two rotating fields. It also describes the starting principles of single phase induction motors using auxiliary windings.
Double Field Revolving Theory Explained | PDF | Electric Motor ... - Scribd
In this topic, you study Double Revolving Field Theory. When a single-phase stator winding is connected to a source of alternating voltage, the current flowing through this winding produces a field which varies sinusoidally with time along a fixed space axis.
It explains how the double revolving field theory resolves a single pulsating magnetic field into two opposite rotating fields, and illustrates the behavior of these fields over a cycle to demonstrate the nature of alternating flux.
According to the double revolving field theory of single-phase induction motor, a stationary pulsating magnetic field can be resolved into two rotating magnetic fields. Both the magnetic fields are of equal magnitude but rotating in opposite directions.
This peculiar behaviour of the motor can be explained in two ways (i) by two -field or double- field revolving theory and (ii) by cross-field theory. According to double field revolving theory, an alternating uniaxial quantity can be represented by two oppositely rotating vectors of half magnitude.