What is the value of the stator induced voltage with respect to the supply voltage?

In an AC motor, the value of the stator induced voltage relative to the supply voltage depends on several factors including the type of motor, operational conditions, and the physical principles governing its operation. To understand this relationship, a bit of background information is necessary.

For induction motors, which are among the most common AC motors, the stator induced voltage is a fundamental aspect of their operation. These motors work on the principle of electromagnetic induction, where the supply voltage is applied to the stator winding, creating a rotating magnetic field. This rotating magnetic field then induces a voltage in the rotor, which in turn creates a current if the rotor circuit is closed, and this current interacts with the magnetic field to produce torque.

The value of the stator induced voltage itself is essentially the supply voltage minus any voltage drop across the stator resistance and reactance. However, it’s important to note that this induced voltage in the stator winding is counteracted by what is known as the back EMF (Electromotive Force). This back EMF is generated by the rotor currents in their rotation and acts against the supply voltage.

The exact relationship or the formula to calculate the stator induced voltage in respect to the supply voltage can get complex, as it involves properties such as the motor’s impedance (which combines both resistance and reactance), the slip speed of the motor, and the applied frequency. For an ideal, lossless induction motor operating under no load, the stator induced voltage would be