Efficiency derived from motor voltage & duty

[ACharnley]

I've a motor, which powers a generator, which feeds into a converter, which gives out voltage/amps, which is measured.

The voltage into the motor is DC and fixed at 25V. The resistance could be measured but I haven't done so.

If the duty is 100% and no load is applied the motor will spin fast. If a load is applied the motor will spin slower, but would the current change?

If I were to measure the current at 100% duty beforehand, and if current is linear with duty cycle, I could calculate the wattage for a given duty cycle and use this to compute system efficiency.

Would it work?

 

[Nigel Goodwin]

As load increases then current input (and output) increases - however, the entire scheme sounds massively inefficient in the first place, why add a a motor and generator in the first place?.

 

[Visitor]

Motor-generators are commonly used where it is necessary to change power frequency. DC to 50Hz or 60Hz. 60Hz to 400Hz.

 

[Nigel Goodwin]

Motor-generators are commonly used where it is necessary to change power frequency. DC to 50Hz or 60Hz. 60Hz to 400Hz.

Perhaps you missed the converter at the end of them both?. I'd also suggest 'were used' rather than 'are used', as it's antique obsolete technology - and the system was pretty inefficient anyway.

 

[Visitor]

No Nigel, I know you are older than dirt, but your experience doesn't prove or disprove anything. Just because you haven't seen something does not prove its doesn't exist.

 

[Visitor]

Weird that a company could build its business around
"antique obsolete technology".

Perhaps they know of applications beyond your knowledge.