ELECTRICAL POWER SYSTEMS

Electrical power systems and methods of controlling electrical power systems are described. One such electrical power system comprises: a first ac bus 21 and a first generator set 11, G1 configured to supply the first ac bus 21 with ac electrical power; a second ac bus 22 and a second generator set 12, G2 configured to supply the second ac bus 22 with ac electrical power; an interconnecting transformer 15 connected between the first and second ac busses 21, 22; a primary electrical load M1, M2 connected to both the first and second ac busses 21, 22 via a converter arrangement 31, 32; an auxiliary load 51 connected to the first ac bus 21; and a controller 17 configured to control the first generator set 11, G1 according to a first droop control profile and to control the second generator set 12, G2 according to a second droop control profile, the first and second droop control profiles relating respective generator operating frequencies of the first and second generator sets 11, G1; 12, G2 to respective output powers of the first and second generator sets 11, G1; 12, G2.