Abstract: A system includes a mechanical load, a first electrical motor and associated motor drive and a second electrical motor and associated motor drive. The first electrical motor and the second electrical motor being configured to drive the mechanical load in parallel. Each electrical motor and associated motor drive have a respective position sensor configured to measure the output position of the mechanical load; and each motor drive comprises a respective controller configured to output a current demand for its associated motor based on a position error between a desired output position of the mechanical load and the measured output position of the mechanical load from its respective position sensor, and a feedback signal of its output current demand.

Abstract: A power converter for providing power to one or more loads. The power converter is configured to be arranged in a parallel configuration with one or more additional power converters. The converter includes: a load balancing controller configured to receive an input voltage demand and output a compensated output voltage demand; an inverter for receiving an input voltage and converting this to an output voltage having an associated output current, the inverter comprising at least two DC-link capacitors; and a module configured to modulate the output voltage using a modulation scheme based on the compensated output voltage demand. The load balancing controller comprises a first feedback circuit configured to generate a first signal, wherein the first signal is generated based on a first measurement/calculation of the output current of the inverter scaled by a first gain.

Abstract: A controller for a switched reluctance machine, the machine comprising two concurrently energised phases and two concurrently non-energised phases. The controller is configured to, in an injection stage, inject a signal into the two non-energised phases; in a measurement stage, determine a current in each of the two non-energised phases; and in a calculation stage, apply an algorithm to the determined currents to determine a rotor angle.

Abstract: A control system for an aerospace vehicle includes a voter and a plurality of control blocks. Each control block includes: a controller configured to receive an input signal and perform a control algorithm that includes an integral function on the input signal to provide an output signal; and a feedback controller that is configured to: receive the output signal from the controller, a reference signal from an external controller, and a plant feedback signal from an external plant; perform a feedback algorithm on the output signal to provide an feedback control signal; and perform a combinator algorithm using the reference signal, the plant feedback signal and the feedback control signal to provide the input signal to the controller; wherein the voter is configured to receive the output signals and perform a voting algorithm on the output signals to determine a control signal to provide to the external plant.

Abstract: There is provided herein a method of advancing phase of a DQ reference frame in a Field Oriented Control, FOC, algorithm for a permanent magnet motor. The method comprises: monitoring a component of the stator voltage demand of the permanent magnet motor, when the component of the stator voltage demand surpasses a threshold, calculating a phase advance angle, ?adv, based on a gain multiplied by the difference between the component of stator voltage demand and the threshold; and advancing phase of the DQ reference frame in the FOC algorithm based on the calculated phase advance angle, up to a maximum phase advance angle when motor speed is positive, or down to a minimum phase angle when motor speed is negative.

Abstract: There is provided herein an electrical motor and associated motor drive. The motor comprises an output shaft, and a speed sensor configured to measure the speed of the output shaft. The motor drive comprises a controller configured to output a current demand for the motor based on a speed error between a desired speed of the output shaft and the measured speed of the output shaft, and a feedback signal of the output current demand scaled by a first gain.

Abstract: A proportional integrator for control of a motor drive arranged to be connected in parallel with one or more other motor drives to drive a common load. The proportional integrator includes means to receive an input command signal and to compare with a local measured signal from the motor drive and to output a local control signal for that motor drive, further comprising a global input signal indicative of the behaviour of the one or more other motor drives, the global input signal being incorporated into the proportional integral function with the input command signal and the local measured signal to provide the local control signal.

Abstract: A power converter for providing power to one or more loads. The power converter is configured to be arranged in a parallel configuration with one or more additional power converters. The converter includes: a load balancing controller configured to receive an input voltage demand and output a compensated output voltage demand; an inverter for receiving an input voltage and converting this to an output voltage having an associated output current, the inverter comprising at least two DC-link capacitors; and a module configured to modulate the output voltage using a modulation scheme based on the compensated output voltage demand. The load balancing controller comprises a first feedback circuit configured to generate a first signal, wherein the first signal is generated based on a first measurement/calculation of the output current of the inverter scaled by a first gain.

Abstract: A system for providing power to one or more loads. The system includes: a central controller configured to output a speed demand for one or more loads; and a plurality of power converters arranged in a parallel configuration with each other and configured to provide power to the one or more loads. Each power converter includes a speed control loop configured to calculate a local current demand based at least in part on an output speed error between the speed demand of the one or more loads and a measured speed of the one or more loads; a torque/current control loop configured to calculate an output voltage demand based at least in part on the local current demand of its respective speed control loop; and a module configured to modulate the output voltage of an inverter based on the output voltage demand from the torque/current control loop.

Abstract: Methods of operating electric motor systems that comprise electric motors comprising a rotor having a magnet mounted thereto. The electric motor is initially operated in an open loop mode in which the rotor angle is estimated based on the input voltage frequency. Once the motor is running at sufficient speed, a transition to closed loop mode operation is performed, wherein the rotor angle is determined using an observed back EMF. To provide a smoother open loop to closed loop transition, the rotor angle is determined during a transition period as a function of both the open loop rotor angle and the closed loop rotor angle.

Abstract: A controller for an electrical drive system includes one or more electrical drives, one or more electrical loads, and a switching component configured to connect the one or more electrical drives to the one or more electrical loads in a switching configuration. The controller includes a processing module configured to receive switching data indicative of the switching configuration and analyze the switching data to determine control data for at least one of the electrical drives. The controller further includes an output module configured to output the control data to the at least one electrical drive. The at least one electrical drive is configured to use the control data to supply the electrical load/s, via the switching component, with electrical power.

Abstract: A controller for a switched reluctance machine, the machine comprising two concurrently energised phases and two concurrently non-energised phases. The controller is configured to, in an injection stage, inject a signal into the two non-energised phases; in a measurement stage, determine a current in each of the two non-energised phases; and in a calculation stage, apply an algorithm to the determined currents to determine a rotor angle.

Abstract: A system for controlling one or more loads. The system comprises a plurality of power converters, wherein each power converter is configured to be arranged in a parallel configuration with one or more additional power converters so as to control the one or more loads, and a central controller configured to output a common reference based on local current or voltage values received from each power converter; and transmit the common reference to each of the power converters. Each power converter comprises an inverter configured to control the one or more loads based on voltage switching signals, a module configured to provide the voltage switching signals to the inverter according to a modulation scheme.

Abstract: There is provided a system for providing (e.g., configured to provide) power to one or more loads. The system comprises a plurality of power converters, wherein each power converter is configured to be arranged in a parallel configuration with one or more additional power converters so as to provide power to the one or more loads. The system further comprises a central controller configured to receive a plurality of local current measurement values from each of the power converters, output a global current measurement value based on the local current measurement values, and transmit the global current measurement value to each of the power converters, wherein each power converter comprises an inverter for receiving an input voltage and converting this to an output voltage having one or more associated output current(s).

Abstract: A control system for an aerospace vehicle includes a voter and a plurality of control blocks. Each control block includes: a controller configured to receive an input signal and perform a control algorithm that includes an integral function on the input signal to provide an output signal; and a feedback controller that is configured to: receive the output signal from the controller, a reference signal from an external controller, and a plant feedback signal from an external plant; perform a feedback algorithm on the output signal to provide an feedback control signal; and perform a combinator algorithm using the reference signal, the plant feedback signal and the feedback control signal to provide the input signal to the controller; wherein the voter is configured to receive the output signals and perform a voting algorithm on the output signals to determine a control signal to provide to the external plant.

Abstract: A system includes a mechanical load, a first electrical motor and associated motor drive and a second electrical motor and associated motor drive. The first electrical motor and the second electrical motor being configured to drive the mechanical load in parallel. Each electrical motor and associated motor drive have a respective position sensor configured to measure the output position of the mechanical load; and each motor drive comprises a respective controller configured to output a current demand for its associated motor based on a position error between a desired output position of the mechanical load and the measured output position of the mechanical load from its respective position sensor, and a feedback signal of its output current demand.

Abstract: A proportional integrator for control of a motor drive arranged to be connected in parallel with one or more other motor drives to drive a common load. The proportional integrator includes means to receive an input command signal and to compare with a local measured signal from the motor drive and to output a local control signal for that motor drive, further comprising a global input signal indicative of the behaviour of the one or more other motor drives, the global input signal being incorporated into the proportional integral function with the input command signal and the local measured signal to provide the local control signal.

Abstract: A proportional integrator for control of a motor drive arranged to be connected in parallel with one or more other motor drives to drive a common load. The proportional integrator includes means to receive an input command signal and to compare with a local measured signal from the motor drive and to output a local control signal for that motor drive. Also includes are a global input signal indicative of the behaviour of the one or more other motor drives, the global input signal being incorporated into the proportional integral function with the input command signal and the local measured signal to provide the local control signal.

Abstract: An electric motor system that comprises a motor that comprises a rotor having a magnet mounted thereto and a stator that comprises one or more motor phase windings for driving rotation of the rotor when the motor phase windings receive an input voltage from an electrical power supply. The system has a controller that executes a back “EMF” observer that is operable to estimate a rotor angle by observing a back electromotive force induced in the stator by the rotor. Filtering is applied to the back EMF signal to reduce harmonics prior to determining the rotor angle.

Abstract: There is provided herein a method of advancing phase of a DQ reference frame in a Field Oriented Control, FOC, algorithm for a permanent magnet motor. The method comprises: monitoring a component of the stator voltage demand of the permanent magnet motor, when the component of the stator voltage demand surpasses a threshold, calculating a phase advance angle, ?adv, based on a gain multiplied by the difference between the component of stator voltage demand and the threshold; and advancing phase of the DQ reference frame in the FOC algorithm based on the calculated phase advance angle, up to a maximum phase advance angle when motor speed is positive, or down to a minimum phase angle when motor speed is negative.