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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 supply system for kVAr compensation.

The ship’s total consumer load is 1200 kW at 0.8 power factor lagging and the synchronous motor takes 70 kW.

(a) Sketch a clearly labelled single-line diagram of the power system. (2)

(b) The shaft-generator is loaded to its rated output of 750 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;      (8)

(ii) the load current supplied by the diesel generator;(3)

(iii) the power factor of the synchronous motor.(3)