Abstract: Electrical power systems and methods of controlling electrical power systems are described. One such electrical power system comprises: a first ac bus and a first generator set configured to supply the first ac bus with ac electrical power; a second ac bus and a second generator set, configured to supply the second ac bus with ac electrical power; an interconnecting transformer connected between the first and second ac busses; a primary electrical load connected to both the first and second ac busses via a converter arrangement; an auxiliary load connected to the first ac bus; and a controller configured to control the first generator set according to a first droop control profile and to control the second generator set 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 to respective output powers of the first and second generator sets.

Abstract: Electrical power systems and methods of controlling electrical power systems are described. One such electrical power system comprises: a first ac bus and a first generator set configured to supply the first ac bus with ac electrical power; a second ac bus and a second generator set, configured to supply the second ac bus with ac electrical power; an interconnecting transformer connected between the first and second ac busses; a primary electrical load connected to both the first and second ac busses via a converter arrangement; an auxiliary load connected to the first ac bus; and a controller configured to control the first generator set according to a first droop control profile and to control the second generator set 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 to respective output powers of the first and second generator sets.

Abstract: A variable speed drive arrangement including: a load; a gearbox to supply mechanical drive to the load; a converter electrically coupled with a power grid. Also a primary electrical machine to supply mechanical power to the gearbox and to receive electrical power; and a secondary electrical machine mechanically coupled to the gearbox and electrically coupled to the converter. An electrical circuit breaker to selectively electrically couple the primary electrical machine to the secondary electrical machine or to the power grid; wherein the secondary electrical machine is adapted to supply or extract mechanical energy from the gearbox and to receive or deliver electrical energy to the converter. Also a control method for the arrangement including a starting mode and a running mode.

Abstract: An electromagnetic machine, comprising: a first stator winding having a first number of pole pairs; a second stator winding having a second number of pole pairs which is different to the first number of pole pairs; and, a modulator having a plurality of pole pieces arranged relative to the first and second stator windings so as to modulate the electromagnetic fields produced by the first and second stator windings, thereby matching harmonic spectra of the first and second stator windings.

Abstract: A variable speed drive arrangement including: a load; a gearbox to supply mechanical drive to the load; a converter electrically coupled with a power grid. Also a primary electrical machine to supply mechanical power to the gearbox and to receive electrical power; and a secondary electrical machine mechanically coupled to the gearbox and electrically coupled to the converter. An electrical circuit breaker to selectively electrically couple the primary electrical machine to the secondary electrical machine or to the power grid; wherein the secondary electrical machine is adapted to supply or extract mechanical energy from the gearbox and to receive or deliver electrical energy to the converter. Also a control method for the arrangement including a starting mode and a running mode.

Abstract: An electromagnetic machine, comprising: a first stator winding having a first number of pole pairs; a second stator winding having a second number of pole pairs which is different to the first number of pole pairs; and, a modulator having a plurality of pole pieces arranged relative to the first and second stator windings so as to modulate the electromagnetic fields produced by the first and second stator windings, thereby matching harmonic spectra of the first and second stator windings.

Abstract: An electrical system architecture, for example for an aircraft, including a generator driven by an engine of the aircraft to generate electrical energy, which is arranged for extracting the said electrical energy as an AC signal for supply to a system bus. The electrical system architecture also includes an active rectifier coupled to the system bus, that is adapted to rectify the AC signal to a DC signal for supply to a load in the system, and for controlling extraction of the said electrical energy by the generator. An electrical power generation system, including a generator, including a stator and a rotor, for converting mechanical power into alternating current electrical power by electromagnetic induction, and an active rectifier for converting the alternating current output of the generator into direct current electrical power is provided.

Abstract: An electrical generation system, including: a differential gearbox having an output drive, an input drive and a third drive which can be driven by or drive a load in use; a generator connected to and drivable by the output drive of the differential gearbox; a variable speed primary power source connected to the input drive of the differential gearbox; a regulating electrical machine which is operable as a motor and a generator connected to the third drive of the differential gearbox; at least one switch through which power is supplied to the electrical machine from the electrical output of the generator; and, a control system which monitors the electrical condition of the generator output.