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Q5) A THREE-phase, 440 V, shaft driven generator shares the total electric load of a ship with an auxiliary diesel generator. An over-excited synchronous motor is used in the supply system for kVAr compensation.

The ship’s consumer load is 1 MW at 0.83 power factor lagging and the synchronous motor takes 40 kW.

(a) Sketch a single-line diagram of the power system. (3)

(b) The shaft-generator is loaded to its rated output of 650 kW at unity power factor; the diesel generator is operated at a power factor of 0.9 lagging.

Determine EACH of the following:

(i) the kW and kVAr loading of the diesel generator; (5)

(ii) the load current supplied by the diesel generator; (2)

(iii) power factor of the synchronous motor. (6)