60Hz to 50Hz generator conversion 1

[Marke]

Hi

To convert a 60Hz genset to 50Hz, we need to slow the diesel engine and reduce the excitation (Drop the output voltage)

While I have done this on medium sized machines with no difficulty, are there any problems doing this on large machines? the suggestion from the manufacturer is that the injectors and supercharger would need to be replaced.

I am interested in your comments.

Best regards,

Mark Empson

http://www.lmphotonics.com

 

[aolalde]

I assume that the optimum power output and efficiency of an engine is designed for the nominal speed. As any motor when the speed drops, the power output drops proportional to the speed assuming that the torque produced is constant.

May be a Mechanical Engineering Forum could give a more accurate answer.

In regard to the generator, if the speed is reduced, the generated voltage will be reduced too, ( e=-NKdF/dt, were N is the series turns and dF/dt the flux rate change).

If the excitation is kept constant, the voltage will drop proportional to the speed (83.3% of that at 60 HZ).

As a result the generator Power is reduced too. If the excitation is increased as compared to that for 60HZ, the magnetic circuit could be saturated, overheating the field and the exciter. Another factor is the cooling fans, with reduced speed they will provide lower cooling air.

As a resume, a 60 HZ generator could work at 50 HZ but with reduced power and voltage. If the excitation is reduced the drop in power is more significant, following the voltage drop.

 

[jbartos]

Suggestion: Visit

http://www.kohlerpowersystems.com/pdf/G5236.PDF

and compare parameters for 60Hz and 50Hz at 220V/380V
e.g.
50Hz 60Hz 50Hz/60Hz=0.83
kW 1760 2000 1760kW/2000kW=0.88
kVA 2200 2500 2200kVA/2500kVA=0.88
Amps 3798 3343 3343A/3798A=0.88
RPM 50 60 50RPM/60RPM=0.83
Etc.