With reference to two identical generators operating in parallel supplying a switchboard that automatically shares load equally, explain EACH of the following: (a) the effect of the excitation of one generator reducing while the load remains constant;(5) (b) the possible effects of closing the main circuit breaker when frequency and voltage are equal but phases are out of phase. (5)
With reference to load sharing of a.c. generators: (a) state the meaning of the term speed droop;(3) (b) explain the effect of running generators in parallel with different speed droop settings for EACH of the following: (i) when the generators are sharing the load equally;(3) (ii) when the load suddenly increases.(4)
With reference to AVRS: (a) explain their purpose;(4) (b) explain the effects that would be observed should an AVR give a low output when the generator is: (i) running on its own;(2) (ii) running in parallel with a second generator whose AVR has no fault.(4)
