Voltage Drops When Load Increases

W

Thread Starter

welly

650KW Turbine generator Diodes got damage, causing no voltage build up or no excitation.

New diodes fixed and excitation took place and voltage come on the phases with a frequency of 50 Hz and turbine Turbine speed of 1500 RPM. Turbine runs smoothly on no load, but voltage keeps dropping when load is picked, until the main supply breaker trip off.

the following has been checked and done

1. check for no loose connection of the terminals

2. Phase to phase voltage reads 392 volt

3. Phase to neutral voltage reads 228 volt

4. Main breaker and bus bars have been check for no short circuit

Is it possible the AVR is also damage and need to be change?
 
Thanks, but unfortunately the regulators on the AVR are not responding, when regulated. Any other suggestion on how to manually regulate the voltage?
 
1-Please check the number specifications of replaced diodes whether these are same as old damaged diodes.

2- Replace the AVR with same specifications.

3- Check out the resistance and Insulation test of
rotor winding.

4- Check out the resistance and IR test of exciter stator, rotor and PMG rotor winding.

Regards
Shaheed
 
Hi Shaheed,

Your suggestion of checks will be observe and applied.

Thanks so much
Best Regards

Welly
 
Top