Question

Shunt generator having drooping characteristic are best suited for parallel operation

Because of their slightly drooping voltage characteristics, shunt generators are most suited for stable parallel operation.

Their satisfactory operation is due to the fact that any tendency on the part of a generator to take more or less than its proper share of load results in certain changes of voltage in the system which immediately oppose this tendency thereby restoring the original division of load.

Hence, once paralleled, they are automatically held in parallel.

Similarly, for taking a generator out of service, its field is weakened and that of the other generator is increased till the ammeter of the generator to be cleared reads zero.

After that, its breaker and then the switch are opened thus removing the generator out of service.

This method of connecting in and removing a generator from service helps in preventing any shock or sudden disturbance to the prime-mover or to the system itself.

It is obvious that if the field of one generator is weakened too much, then power will be delivered to it and, it will run in its original direction as a motor, thus driving its prime-mover.