Abstract: In an electrical machine which has time-varying or position-varying disturbances in its output, signals representing the position and values of machine-related parameters are used to solve a model of the machine to calculate the phase currents which are required to minimize the disturbances. The model is able to provide solutions in the presence of limitations of some of the operating conditions of the machine, for example the supply voltage or the error in the signal representing the position.

Abstract: In an electrical machine which has time-varying or position-varying disturbances in its output, signals representing the position and values of machine-related parameters are used to solve a model of the machine to calculate the phase currents which are required to minimise the disturbances. The model is able to provide solutions in the presence of limitations of some of the operating conditions of the machine, for example the supply voltage or the error in the signal representing the position.

Abstract: A variable reluctance generator has phase windings and a bias winding. By controlling the excitation produced by the bias winding, the speed of the machine or the DC link, a power converter using only diodes can supply power to a DC bus. A method of operating a variable reluctance machine as a generator, the machine having at least one phase winding, includes creating a bias flux linking the or at least one phase winding, and limiting the phase voltage to a magnitude below that otherwise induced in the phase winding by the bias flux.

Abstract: A variable reluctance generator has phase windings and a bias winding. By controlling the excitation produced by the bias winding, the speed of the machine or the DC link, a power converter using only diodes can supply power to a DC bus. A method of operating a variable reluctance machine as a generator, the machine having at least one phase winding, includes creating a bias flux linking the or at least one phase winding, and limiting the phase voltage to a magnitude below that otherwise induced in the phase winding by the bias flux.

Abstract: An electrical machine includes a rotor, a stator operably coupled with the rotor, at least one phase winding operably coupled with the rotor and stator and arranged to establish flux in a magnetic circuit in the machine, and a flux observer adapted to produce a signal indicative of flux-causing voltage across the at least one phase winding. A flux control system includes a flux controller adapted to receive a flux command as an input and to provide a phase coil energization signal as an output. The system also includes an electromagnetic system adapted to receive the phase coil energization signal, the electromagnetic system including at least one phase coil, and a flux observer adapted to provide a feedback signal to the flux controller. The feedback signal corresponds to flux in the electromagnetic system, and the phase coil energization signal provided by the flux controller energizes the electromagnetic system such that flux in the electromagnetic system follows the flux command.

Abstract: An electrical machine includes a rotor, a stator operably coupled with the rotor, at least one phase winding operably coupled with the rotor and stator and arranged to establish flux in a magnetic circuit in the machine, and a flux observer adapted to produce a signal indicative of flux-causing voltage across the at least one phase winding. A flux control system includes a flux controller adapted to receive a flux command as an input and to provide a phase coil energization signal as an output. The system also includes an electromagnetic system adapted to receive the phase coil energization signal, the electromagnetic system including at least one phase coil, and a flux observer adapted to provide a feedback signal to the flux controller. The feedback signal corresponds to flux in the electromagnetic system, and the phase coil energization signal provided by the flux controller energizes the electromagnetic system such that flux in the electromagnetic system follows the flux command.

Abstract: A switched reluctance machine uses a Hall-effect device to detect the flux in the flux path for each machine phase. The flux signal from the Hall-effect device is fed back to a controller which compares the flux feedback with a demand signal to produce an error signal. The error signal is used to control the machine flux using a control law function actuating timed switches for each phase.

Abstract: A brushless electric machine uses a signal of the flux-causing voltage across the or each phase winding for control. Flux is more closely related to machine torque than current control, thus providing more accurate control.

Abstract: A switched reluctance machine uses a Hall-effect device to detect the flux in the flux path for each machine phase. The flux signal from the Hall-effect device is fed back to a controller which compares the flux feedback with a demand signal to produce an error signal. The error signal is used to control the machine flux using a control law function actuating timed switches for each phase.

Abstract: An exercise machine includes a switched reluctance motor which drives a moveable surface upon which a user can exercise. A controller which is responsive to sudden load changes on the moveable surface controls the torque developed by the motor substantially to maintain a desired motor speed output without the need for a flywheel. In a first embodiment, the controller uses a feedback signal from a rotor position encoder and a motor speed indicator to control the motor output using a proportional-plus-integral signal processor. In a second embodiment, a composite state observer is used to provide estimates of the rotor position, motor speed and load disturbance states from which real time closed loop control of the motor speed with load disturbances on the moveable surface is effected. Corresponding methods also are disclosed.