CALCULATING POWER LOSSES IN A TRANSFORMER,VFD AND MOTOR.

[nvrsrinivas100]

Dear sir,

In our cement plant,We are having a RABH fan for which we connected a 730KW motor.The details of the motor are Make:Crompton Greaves Limited. KW:730. Volts:690V.Rotor Amps:0.Rotor Voltage:0. RPM:990. Amps:730A Efficiency:95.8%.Frame:BTPC500F .Year of Mfg.03/2009.

This motor is connected to a ABB VFD.ACS800-04-1060-7. 730KW.

The power is fed to VFD through a transformer.The details of the transformer are Make:PETE Transformers.KVA:1000.HV voltage:6600.LV1 voltage:690V.LV2 Voltage:690V.HV Amps:87.5A.LV1 Amps:418.4 Amps.LV2 Amps:418.4A, 3Phase,50Hz,Connection Symbol:DYN11d).Impedance:4.48We have measured KW at different points.KW at HT braker of Transformer:726.2 KW.KW at the input to VFD:695KW.KW at the output of the VFD:647.65KW.Motor RPM at that time=925.8RPM.We want to increase motor speed further ,at least to 960-970 RPM.But,we are not sure whether motor withstands or not.The power meter at the transformer incoming is showing 726.2 KW.Please help me as my production can be improved if we can run the motor at higher speeds. Thanks,NVRSrinivas

[pradeepkumar]

The loss in a transformer compares the input, or primary power, to the output, or secondary power. Most transformer data show their input and output voltages and the current ratings of both sides.

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