Abstract: A power electronics converter connectable, on a DC-side, to a DC electrical network and either, on an AC-side, to an electrical machine coupled to a drive shaft of an engine or propulsor, or, on a second DC-side, to a battery pack. The power electronics converter includes: a power conversion unit including a plurality of semiconductor switching elements and a DC-link; and a gate driver unit, configured to control the semiconductor switching elements so that the power conversion unit: inverts DC power received from the DC electrical network to AC power and provides the AC power to the electrical machine, rectifies AC power received from the electrical machine to DC power and provides the DC power to the DC electrical network, or performs DC-DC conversion between the DC-electrical network and the battery pack; wherein the gate driver unit includes an equipment health monitoring component.

Abstract: A battery cooling block, including: a housing defining a flow chamber and including a first and second port configured to allow flow of coolant through flow chamber along a first axis; the housing further including a plurality of compartments disposed in the flow chamber, each compartment extending along a respective compartment axis perpendicular to first axis and each compartment configured to receive respective cylindrical battery cell; wherein each compartment is defined by partially open compartment wall within flow chamber, compartment wall including a plurality of wall segments extending parallel to compartment axis and which are circumferentially spaced apart around compartment axis wherein respective battery cell is partially exposed to flow of coolant. A battery assembly, including: plurality of cylindrical battery cells; and battery cooling block as described above.

Abstract: A data logging device for an electric aircraft having charging port for on-ground charging of energy storage system of electric propulsion system of aircraft. Device includes an aircraft-side data storage unit, data interface, trigger signal interface, and control unit. Control unit is configured to detect connection of charging port to ground-side charger based on trigger signal received by control unit from ground-side charger via trigger signal interface. Control unit is configured wherein a state of flight of electric aircraft, control unit collects inflight data from electric aircraft via data interface and saves inflight data to aircraft-side data storage unit. Control unit is also configured wherein a state of on-ground charging of electric aircraft, control unit, on receipt of trigger signal, sends inflight data saved on aircraft-side data storage unit via data interface to charger for forwarding to at least one of a data transmitter and a ground-side data storage unit.

Abstract: A computer-implemented method of determining a value of a reliability parameter of an electrical machine, the method includes: estimating an operating temperature of at least a part of the electrical machine based on a measure of a current drawn or supplied by the electrical machine; and determining the value of the reliability parameter based on the estimated operating temperature.

Abstract: A method of monitoring a health state of a power semiconductor device includes: receiving an initial transient voltage parameter relating to transient voltage of the power semiconductor device when turning on, when it is known to be unaged; receiving an initial transient current parameter relating to transient current of the power semiconductor device when turning on, when it is known to be unaged; determining an initial energy parameter, relating to initial turn-on switching energy or power of the power semiconductor device, when it is known to be unaged; receiving an operating transient voltage parameter relating to the transient voltage of the power semiconductor device in operation; receiving an operating transient current parameter relating to the transient current of the power semiconductor device in operation; determining an operating energy parameter; and determining the health state of the power semiconductor device based on the initial energy parameter and the operating energy parameter.

Abstract: The disclosure relates to thermal management of a power electronics converter. An example embodiment includes a power electronics converter comprising: a first set of terminals connectable to a first voltage supply; a second set of terminals connectable to a second voltage supply; a plurality of semiconductor switches connected between the first and second sets of terminals; a voltage sensor connected to measure a voltage across the second supply; a current sensor connected to measure a current through the second supply; and a controller connected to provide switching signals to the semiconductor switches and to receive voltage and current signals from the voltage and current sensors, the controller configured, for each of the semiconductor switches, to: determine a junction temperature of the semiconductor switch; compare the determined junction temperature to a reference temperature; and adjust a switching gate voltage applied to the semiconductor switch.

Abstract: Monitoring circuitry connectable to power conversion circuitry enclosed within packaging, the power conversion circuitry including terminals providing external connections to nodes of the power conversion circuitry enclosed within the packaging, the monitoring circuitry including: a comparator including a first input terminals connectable to first and second terminals of the power conversion circuitry and a second input terminal connected to a reference voltage, wherein the first and second terminals provide external connections to first and second nodes connected along respective current paths each connected to switching circuitry of the power conversion circuitry enclosed within the packaging, wherein the comparator detects a switch state of the switching circuitry based on a voltage generated at the first input terminal and the reference voltage; processing circuitry connected to the comparator and configured to monitor the power conversion circuitry based on the detected switch state and a signal of the p

Abstract: An electrical machine with a rotor coupled to a drive shaft of an engine; a DC electrical network; a power electronics converter connected, on a DC-side, to the DC electrical network, and, on an AC-side, to the electrical machine, the power electronics converter comprising a plurality of transistors and associated diodes connected in anti-parallel with the transistors; and a controller configured to control switching of the transistors so that the converter either inverts DC power to AC power or rectifies AC power to DC power. The controller is further configured, responsive to a determination that there is a fault in the DC electrical network, to operate in a fault mode in which the controller controls the switching of the transistors so that a fault current is shared between the transistors and the associated diodes.

Abstract: Electrical power systems having variable-voltage DC busses and methods of controlling voltage settings of such busses. One electrical power system comprises: a variable-voltage DC bus; a number N?2 of electrical machines, each electrical machine connected to the variable-voltage DC bus via one of a corresponding number N of converters, each electrical machine and corresponding converter having an index n=(1, . . . , N); and a controller configured to select a voltage setting Vdc_bus for the variable-voltage DC bus and to provide control signals to the converters to control the voltage setting of the variable-voltage DC bus according to the selected voltage setting Vdc_bus. The controller configured to select a voltage setting Vdc_bus greater than or equal to a minimum voltage requirement Vdc_min for the bus. The controller is configured to determine the minimum voltage requirement Vdc_min using present operating speeds of each of the N electrical machines.

Abstract: Electrical power distribution systems and methods of operating electrical power distribution systems are provided. One electrical power distribution system comprises: an electrical power storage unit; a transformer; a first bidirectional converter circuit connected between the electrical power storage unit and a first winding of the transformer; a first DC bus; a second DC bus; a second bidirectional converter circuit connected between the first DC bus and a second winding of the transformer; a third bidirectional converter circuit connected between the second DC bus and a third winding of the transformer; and a controller connected for control of the first, second and third converter circuits to distribute electrical power between the electrical power storage unit, the first DC bus and the second DC bus.

Abstract: A two-start helical heat exchanger comprises a helical baffle extending along a length of the heat exchanger and having first and second surfaces, wherein: the first surface of the baffle is arranged to provide a first helical fluid flow path for a first fluid; and the second surface of the baffle is arranged to provide a second helical fluid flow path for a second fluid, wherein the second fluid flow path is arranged in counter-flow with the first fluid flow path and a casing within which the baffle is mounted. The baffle is arranged such that first and second fluid flow paths are in thermal contact with each other through the baffle, and in thermal contact with the casing. The heat exchanger may be incorporated into a power converter, for example to cool the power converter. The heat exchanger may be used on an aircraft.

Abstract: Electrical power systems having variable-voltage DC busses and methods of controlling voltage settings of such busses. One electrical power system comprises: a variable-voltage DC bus; a number N?2 of electrical machines, each electrical machine connected to the variable-voltage DC bus via one of a corresponding number N of converters, each electrical machine and corresponding converter having an index n=(1, . . . , N); and a controller configured to select a voltage setting Vdc_bus for the variable-voltage DC bus and to provide control signals to the converters to control the voltage setting of the variable-voltage DC bus according to the selected voltage setting Vdc_bus. The controller configured to select a voltage setting Vdc_bus greater than or equal to a minimum voltage requirement Vdc_min for the bus. The controller is configured to determine the minimum voltage requirement Vdc_min using present operating speeds of each of the N electrical machines.

Abstract: An operating condition monitor (100) for monitoring an operating condition of a transistor-based power converter (102), comprising: a sensing apparatus (106) configured to measure a turn-off transient energy of the power converter (102), a processor (108) in communication with the sensing apparatus (106) to receive the measurement of the turn-off transient energy, the processor being configured to: compare the measurement of the turn-off transient energy to a threshold; and issue an event signal based on the comparison to the threshold meeting a comparison criterion. A method (200, 200?) of monitoring an operating state of a transistor-based power converter is also disclosed.

Abstract: A system, method and machine-readable instructions for monitoring a power electronics device. The system involves a semiconductor device, at least one sensor and a processor. The processor is configured to monitor a junction temperature of the semiconductor device by determining from the at least one sensor an on-state resistance of the semiconductor device and calculating the junction temperature of the semiconductor device according to a relationship between the on-state resistance of the semiconductor device and the junction temperature of the semiconductor device. The processor may apply an ageing coefficient to the on-state resistance.

Abstract: A method determines a generator system load and/or rotor angle. The generator system has a generator with a generator terminal outputting electrical power generated by the generator, a transformer and a point of common coupling, PCC, terminal. The transformer is between the generator and PCC terminals. The method includes: determining the generator field current; determining the output voltage, the output current and the power factor and/or angle of the output voltage and output current from the generator terminal, and determining the load angle of the generator system, output voltage from the generator terminal, output current from the generator terminal and the power factor and/or angle; and/or determining the output voltage, the output current and the power factor and/or angle of the output voltage and output current, and determining the rotor angle of the generator system, output voltage, output current from the PCC terminal and the power factor and/or angle.

Abstract: The present disclosure concerns a current limiting circuit for a power converter, which may be used to limit charge and discharge currents for electrical power storage units. In an example embodiment, a current limiting circuit comprises: first and second field effect transistors, each having source, gate and drain connections, wherein the source connection of the first transistor is connected to the gate connection of the second transistor and the source connection of the second transistor is connected to the gate connection of the first transistor; and a resistor connected between the source connections of the first and second transistors, wherein drain connections of the first and second transistors are connectable between a DC electrical power supply and an electrical load for limiting a maximum current flowing between the electrical power supply and the electrical load.

Abstract: Electrical power distribution systems and methods of operating electrical power distribution systems are provided. One electrical power distribution system comprises: an electrical power storage unit; a transformer; a first bidirectional converter circuit connected between the electrical power storage unit and a first winding of the transformer; a first DC bus; a second DC bus; a second bidirectional converter circuit connected between the first DC bus and a second winding of the transformer; a third bidirectional converter circuit connected between the second DC bus and a third winding of the transformer; and a controller connected for control of the first, second and third converter circuits to distribute electrical power between the electrical power storage unit, the first DC bus and the second DC bus.

Abstract: A power system, including: a synchronous electrical generator having a rotor; and an angle computation unit configured to: determine a rotor angle in a steady state period of the synchronous electrical generator, determine a change in rotor angle in a transient period of the synchronous electrical generator, and estimate the rotor angle in the transient period based on the steady state rotor angle and the change in rotor angle.

Abstract: A two-start helical heat exchanger comprises a helical baffle extending along a length of the heat exchanger and having first and second surfaces, wherein: the first surface of the baffle is arranged to provide a first helical fluid flow path for a first fluid; and the second surface of the baffle is arranged to provide a second helical fluid flow path for a second fluid, wherein the second fluid flow path is arranged in counter-flow with the first fluid flow path and a casing within which the baffle is mounted. The baffle is arranged such that first and second fluid flow paths are in thermal contact with each other through the baffle, and in thermal contact with the casing. The heat exchanger may be incorporated into a power converter, for example to cool the power converter. The heat exchanger may be used on an aircraft.

Abstract: A power system includes a synchronous electrical generator having a rotor driven by a shaft; a permanent magnet signaling generator, coupled to the shaft; and an angle computation unit configured to calculate a rotor angle or load angle based on a voltage from the permanent magnet signaling generator and a voltage from the synchronous electrical generator.