PRESENTED BY:
MANJUNATHA B.E

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Abstract-
 As the cost of energy increases it is increasingly more important to remove inefficient motors from operation.
 It describes the results of a very-low-cost & accurate method for determining the motor efficiency without the need for removing the motor & without the need for measuring the output power or torque.
 Test results indicate that the novel method has an accuracy of over 99%.
INTRODUCTION-
Methods:
1.To place the motor on a test stand & instrument it to monitor the i/p & o/p at different load points using dynamometer & torque transducer.
2. using no-load & blocked rotor tests . Blocked-rotor tests require reduced voltage & reduced frequency in addition to prevent the rotor from rotating.
3. using nameplate data & input measurements estimate the efficiency. Error in estimated efficiency is high.
 The new method relies on measuring the i/p voltage, input current, input electrical power ,stator resistance, & output speed of the motor by using an accurate model of the motor.
 The stator resistance can be measured at a given temperature and, later, the resistance of the stator can be estimated by measuring the temperature of the stator.
 The model parameter can be obtained by using the measured variables at no load & one or two operating points.