A supply system feeds the following loads
(i) A lighting load of 500 kW
(ii) A load of 400 kW at a p.f. 0.707 lagging
(iii) A load of 800 kW at a p.f. 0.8 leading
(iv) A load of 500 kW at a p.f. 0.6 lagging
(v) A synchronous motor driving a 540 kW d.c. generator and having an overall efficiency of 90%
Calculate the power factor of the synchronous motor so that station power factor may become unity.