04-04-2011, 04:25 PM
PRESENTED BY:
MANJUNATHA B.E
MANJUEEE.ppt (Size: 992 KB / Downloads: 99)
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.