ELECTRICAL POWER SYSTEM HAVING A DC BUS WITH VARIABLE VOLTAGE SETTING

Electrical power systems 10, 10i having variable-voltage DC busses 15 and methods of controlling voltage settings of such busses 15 are provided. One electrical power system 10, 10i comprises: a variable-voltage DC bus 15; a number N ≥ 2 of electrical machines G1-G4; M1-M4, each electrical machine G1-G4; M1-M4 connected to the variable-voltage DC bus 15 via one of a corresponding number N of converters 21-24; 31-34, each electrical machine G1-G4; M1-M4 and corresponding converter 21-24; 31-34 having an index n = (1,... , N); and a controller 17 configured to select a voltage setting V for the variable-voltage DC bus 17 and to provide control signals to the converters 21-24; 31-34 to control the voltage setting of the variable-voltage DC bus 17 according to the selected voltage setting V. The controller 17 is configured to select a voltage setting V greater than or equal to a minimum voltage requirement V for the bus 15. The controller 17 is configured to determine the minimum voltage requirement V using present operating speeds of each of the N electrical machines G1-G4; M1-M4.