What is the voltage regulation of cumulative generators at high load?
Answers
Which generator has worst voltage regulation?
During On-load conditions its Diffentially Compounded DC generator that has the poorest voltage regulation.
In differential compound machine shunt and series field flux are subtracted and the net field flux is reduced. When the generator is loaded, load current (or armature current) flows through the series field windings creating magnetic flux that opposes the flux created by shunt field. This results in decrease of induced emf and, therefore, in terminal voltage. In such generators the terminal voltage drops very rapidly with the increase in load current and, therefore it is interesting to note that a short- circuit cannot cause any damage to it.
In such a generator, the induced voltage on no-load would be the same as for the shunt generator because series field does not create any flux. So it behaves like DC shunt generator, which has a very good regulation.
For No- load conditions, DC series generator has the poorest regulation .
Please refer the following characteristics for further understanding.