Introducing a method to determine active and reactive power and torque of the induction machine without shaft sensor

This paper proposes a method to determine active (P) and reactive power (Q) and torque of the low cost induction machine without shaft sensor. In this method, active and reactive powers are estimated from the dc-link current. Derivation of torque and flux is based on the estimation of active and reactive power. Reduction of number of sensors, simplifying the cabling and maintenance of the system are the advantages of this method. At the end, the accuracy of this method is compared with a conventional method