Electrical Engineering ⇒ Topic : Equivalent Circuit

EQUIVALENT CIRCUIT OF AN INDUCTION MOTOR:-

The equivalent circuit for a polyphase induction motor is shown in Fig. (a), where

                   V₁= applied voltage per phase

                   R₁= stator resistance/phase

                    R₂,= rotor resistance/phase

                    X₁= stator leakage reactance/phase

                   X₂ = rotor standstill leakage reactance/phase

                      K= turn-ratio of secondary to primary

                   R₀ = no-load resistance/phase                            Rotor being driven at synchronous speed.

                   X₀ = no-load reactance/phase

                                   Fig. (a) Equivalent circuit of an induction motor

As shown in Fig.(a) the exciting circuit may be transferred to the left, because inaccuracy involved is negligible but the circuit and hence the calculations are very much simplified. This is known as the approximate equivalent circuit of the induction motor

EQUIVALENT CIRCUIT

The equivalent circuit of an induction motor is similar to that of transformer. The only difference is that the rotor of induction motor is not static and mechanical power is developed.It has two types :-

• Stator Equivalent Circuit
• Rotor Equivalent Circuit