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: An aircraft fuel system includes a first integrated boost stage having a boost pump configured to receive a fuel flow from a fuel tank via a boost supply line, at least one generator collocated with and operatively connected to the boost pump for driving the boost pump, and a tap fluidly connecting the boost pump and the at least one generator for selectively delivering an amount of the fuel flow to the at least one generator. The fuel system further includes a gearbox operatively connected to the at least one generator, and a main stage downstream of the boost stage and operatively connected to the gearbox. The main stage includes a main pump configured to receive the fuel flow from the boost pump along a main supply line, and a filter disposed along the main supply line upstream of the main pump for filtering the fuel flow.

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 motor drive system includes a three-phase motor and a virtual neutral bridge inverter circuit. The three-phase motor includes a first phase lead, a second phase lead, and a third phase lead. Each of the first phase neutral end, the second phase neutral end, and the third phase neutral end of the phase leads are separated from one another. The virtual neutral bridge inverter circuit includes a first neutral switch pair connected at a first neutral connection node, a second neutral switch pair connected at a second neutral connection node, and a third neutral switch pair connected at a third neutral connection node. The first phase neutral end is connected to the first neutral connection node, the second phase neutral end is connected to the second neutral connection node, and the third phase neutral end is connected to the third neutral connection node.

Abstract: An aircraft fuel system includes a fuel tank, a fuel pump configured to receive a fuel flow from the fuel tank via a fuel supply line. The fuel system further includes a tap fluidly coupled to an outlet of the fuel pump, at least one generator or permanent magnet machine fluidly connected to the fuel pump via the tap, and the tap is configured to deliver fuel to the at least one generator or permanent magnet machine. The fuel system further includes a gearbox mechanically connected to the at least one generator or permanent magnet machine.

Abstract: An aircraft fuel system includes a first integrated boost stage having a boost pump configured to receive a fuel flow from a fuel tank via a boost supply line, at least one generator collocated with and operatively connected to the boost pump for driving the boost pump, and a tap fluidly connecting the boost pump and the at least one generator for selectively delivering an amount of the fuel flow to the at least one generator. The fuel system further includes a gearbox operatively connected to the at least one generator, and a main stage downstream of the boost stage and operatively connected to the gearbox. The main stage includes a main pump configured to receive the fuel flow from the boost pump along a main supply line, and a filter disposed along the main supply line upstream of the main pump for filtering the fuel flow.

Abstract: A fluid delivery system is provided including a reservoir including oil, a hydraulic pump in fluid communication with the reservoir, and a heat exchanger system. The heat exchanger system is in fluid communication with the hydraulic pump, a generator, and an engine gearbox. The hydraulic pump is configured to deliver the oil to the heat exchanger system. The heat exchanger system is configured to provide the oil according to first temperature criteria to the generator and provide the oil according to second temperature criteria to the engine gearbox.

Abstract: A fuel delivery system for a gas turbine engine includes a fuel source and a main fuel pump configured to deliver a first flow of fuel to a combustor assembly of the gas turbine engine under a first, relatively high fuel demand operating condition of the gas turbine engine. A secondary fuel pump is configured to deliver a second flow of fuel to the combustor assembly under a second, relatively low fuel demand operating condition of the gas turbine engine.

Abstract: A fuel pumping system for delivering fuel to an engine component includes a boost pump having a boost pump outlet and a main pump having a main pump inlet and a main pump outlet. The main pump inlet is fluidly connected to the boost pump outlet via a main pump feed conduit. A fuel control conduit is fluidly connected to the main pump outlet and to the engine component. A third pump has a third pump inlet and a third pump outlet. The third pump outlet is fluidly connected to the engine component. A third pump conduit is fluidly connected to the main pump outlet and to the third pump inlet. A valve is operable to control a fuel flow to the third pump in response to a pressurization demand of the engine component.

Abstract: A controllable pump system can include an inlet line and a pressure controlled pump connected to the inlet line to receive input flow. The pressure controlled pump can have a pressure controlled pump state configured to control a pump output to an output line connected to the pressure controlled pump. The system can include a slew pump connected to the inlet line and configured to output a slew pump pressure, and a slew pressure valve connected to the input line and to a second line and configured to output a control pressure to the pressure controlled pump. The second line can be configured to be in fluid communication with at least the slew pump such that the slew pressure valve can receive the slew pump pressure.

Abstract: A fluid delivery system is provided including a reservoir including oil, a hydraulic pump in fluid communication with the reservoir, and a heat exchanger system. The heat exchanger system is in fluid communication with the hydraulic pump, a generator, and an engine gearbox. The hydraulic pump is configured to deliver the oil to the heat exchanger system. The heat exchanger system is configured to provide the oil according to first temperature criteria to the generator and provide the oil according to second temperature criteria to the engine gearbox.

Abstract: A fuel delivery system for a gas turbine engine includes a fuel source and a main fuel pump configured to deliver a first flow of fuel to a combustor assembly of the gas turbine engine under a first fuel demand operating condition of the gas turbine engine. A secondary fuel pump is arranged in a fluidly parallel relationship with the main fuel pump. The secondary fuel pump is configured to deliver a second flow of fuel to the combustor assembly under a fuel demand second operating condition, different from the first fuel demand operating condition of the gas turbine engine.

Abstract: A system includes a main pump having a main pump shaft configured to connect to a gear box for driving the main pump with rotational power from the gear box in a run mode, and for driving the gear box with rotational power from the main pump in a start mode. The system includes a first fuel line with an inlet configured to connect to connected in fluid communication with a fuel source. The first fuel line includes a first branch in fluid communication with the main pump, and a second branch. A start pump is connected in fluid communication with the second branch of the first fuel line. A second fuel line connects the start pump in fluid communication with a pump management valve (PMV). A third fuel line connects the main pump in fluid communication with the pump management valve.

Abstract: A system includes a main pump having a main pump shaft configured to connect to a gear box for driving the main pump with rotational power from the gear box in a run mode, and for driving the gear box with rotational power from the main pump in a start mode. The system includes a first fuel line with an inlet configured to connect to connected in fluid communication with a fuel source. The first fuel line includes a first branch in fluid communication with the main pump, and a second branch. A start pump is connected in fluid communication with the second branch of the first fuel line. A second fuel line connects the start pump in fluid communication with a pump management valve (PMV). A third fuel line connects the main pump in fluid communication with the pump management valve.

Abstract: In accordance with at least one aspect of this disclosure, a system includes a fuel line, an electrically driven fuel pump configured to supply fuel to a first fuel line branch and a second fuel line branch, and a selector valve disposed in the fuel line at a juncture of a first fuel line branch and a second fuel line branch configured to communicate the electrically driven fuel pump with the first fuel line branch or the second fuel line branch based on a position of the selector valve. In a first position, the selector valve is configured to fluidly connect the electrically driven fuel pump with the first fuel line branch to supply fuel to a combustor of the engine and drive a high pressure shaft at a first speed. In a second position, the selector valve is configured to fluidly connect the electrically driven fuel pump with the second fuel line branch to drive a hydraulic rotation unit configured to drive the high pressure spool of the engine at a second speed different from the first speed.

Abstract: In accordance with at least one aspect of this disclosure, a system includes a fuel line, an electrically driven fuel pump configured to supply fuel to a first fuel line branch and a second fuel line branch, and a selector valve disposed in the fuel line at a juncture of a first fuel line branch and a second fuel line branch configured to communicate the electrically driven fuel pump with the first fuel line branch or the second fuel line branch based on a position of the selector valve. In a first position, the selector valve is configured to fluidly connect the electrically driven fuel pump with the first fuel line branch to supply fuel to a combustor of the engine and drive a high pressure shaft at a first speed. In a second position, the selector valve is configured to fluidly connect the electrically driven fuel pump with the second fuel line branch to drive a hydraulic rotation unit configured to drive the high pressure spool of the engine at a second speed different from the first speed.

Abstract: A controllable pump system can include an inlet line and a pressure controlled pump connected to the inlet line to receive input flow. The pressure controlled pump can have a pressure controlled pump state configured to control a pump output to an output line connected to the pressure controlled pump. The system can include a slew pump connected to the inlet line and configured to output a slew pump pressure, and a slew pressure valve connected to the input line and to a second line and configured to output a control pressure to the pressure controlled pump. The second line can be configured to be in fluid communication with at least the slew pump such that the slew pressure valve can receive the slew pump pressure.

Abstract: A motor drive system includes a three-phase motor and a virtual neutral bridge inverter circuit. The three-phase motor includes a first phase lead, a second phase lead, and a third phase lead. Each of the first phase neutral end, the second phase neutral end, and the third phase neutral end of the phase leads are separated from one another. The virtual neutral bridge inverter circuit includes a first neutral switch pair connected at a first neutral connection node, a second neutral switch pair connected at a second neutral connection node, and a third neutral switch pair connected at a third neutral connection node. The first phase neutral end is connected to the first neutral connection node, the second phase neutral end is connected to the second neutral connection node, and the third phase neutral end is connected to the third neutral connection node.

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 two stage fuel delivery system for an aircraft includes a first stage pump including an inlet connected to a source of fuel and an outlet connected to a combustor assembly, and a second stage pump including an inlet portion connected to the source of fuel and an outlet portion connected to the combustor assembly. A bypass valve is connected between the source of fuel, the inlet, and the inlet portion. The bypass valve selectively disconnects the second stage pump from the source of fuel. A metering valve is connected to the inlet and the inlet portion. The metering valve includes a metering valve inlet and a metering valve outlet. A pressure regulating valve is connected to the metering valve. A stage monitoring system is configured to detect a change in operation of the second stage and control the bypass valve.