An electrical power system for distributing electrical power in an arrangement comprising one or more gas turbine engines, the electrical power system comprising: one or more rotary electric machines, each mechanically coupled to a gas turbine engine spool; a set of converter circuits connected to the one or more rotary electric machines for conversion between alternating current, ac, and direct current, dc, wherein the one or more rotary electric machines and the set of converter circuits are arranged to output a number R ≥ 2 of dc power channels, each dc power channel having a respective index r = (1,..., R); a group of N dc load channels connected to the R power channels by a switching arrangement, wherein N > R and each dc load channel has a respective index n = (1,..., N); and a poly-phase electrical load connected to and powered by the N load channels, wherein: the switching arrangement is operable to connect a number Q ≥ 1 of the N load channels to at least two different power channels of the R power channels, the system further comprises a controller configured to control the operation of the switching arrangement to control which of the power channels the N load channels receive electrical power from; and characterised in that the controller is configured to control the switching arrangement so that, in a no fault condition, pairs of phases (A1-D1) of the poly-phase electrical load are powered by the same power channels so as to cancel harmonics in current supplied by the power channels. one or more rotary electric machines, each mechanically coupled to a gas turbine engine spool; a set of converter circuits connected to the one or more rotary electric machines for conversion between alternating current, ac, and direct current, dc, wherein the one or more rotary electric machines and the set of converter circuits are arranged to output a number R ≥ 2 of dc power channels, each dc power channel having a respective index r = (1,..., R); a group of N dc load channels connected to the R power channels by a switching arrangement, wherein N > R and each dc load channel has a respective index n = (1,..., N); and a poly-phase electrical load connected to and powered by the N load channels, wherein: the switching arrangement is operable to connect a number Q ≥ 1 of the N load channels to at least two different power channels of the R power channels, the system further comprises a controller configured to control the operation of the switching arrangement to control which of the power channels the N load channels receive electrical power from; and characterised in that the controller is configured to control the switching arrangement so that, in a no fault condition, pairs of phases (A1-D1) of the poly-phase electrical load are powered by the same power channels so as to cancel harmonics in current supplied by the power channels. the switching arrangement is operable to connect a number Q ≥ 1 of the N load channels to at least two different power channels of the R power channels, the system further comprises a controller configured to control the operation of the switching arrangement to control which of the power channels the N load channels receive electrical power from; and characterised in that the controller is configured to control the switching arrangement so that, in a no fault condition, pairs of phases (A1-D1) of the poly-phase electrical load are powered by the same power channels so as to cancel harmonics in current supplied by the power channels.