Abstract: In some examples, an electrical power system includes a solid state power converter including a first set of switches on a source side of the solid state power converter and a second set of switches on a load side of the solid state power converter. The electrical power system also includes a power source connected to the source side of the solid state power converter and also includes a differential bus connected to the load side of the solid state power converter. The electrical power system further includes a controller configured to receive a first signal indicating a current at the source side and receive a second signal indicating a current at the load side. The controller is further configured to detect, based on a time derivative of the first signal and a time derivative of the second signal, a fault in the electrical power system.

Abstract: A thermal management system for an energy storage system for an aircraft includes a pump circulating a thermal management fluid through the thermal management system and an energy storage device of the aircraft. A controller circuitry may control a variable pumping capacity of the pump based on sensing pressure or temperature of the thermal management fluid at the energy storage device. The controller circuitry may default operation of the pump to a first pumping capacity in response to the pressure or temperature being within a predetermined operating range and a predetermined failure condition or a power demand of an aircraft engine supply bus exceeding a predetermined threshold. The controller controlling operation of the pump to a second pumping capacity in response to absence of the power demand signal of the aircraft engine supply bus and the pressure or temperature being within the predetermined operating range.

Abstract: Methods of controlling an in-line heater for an energy storage device are provided. A determination is made that a pump is running. When running, the pump circulates a thermal management fluid through a thermal management conditioning loop, which includes the in-line heater and a heat transfer hardware configured to transfer heat between the thermal management fluid and the energy storage device, wherein the in-line heater is in thermal communication with the thermal management fluid. The in-line heater is turned on in response to the determination that the pump is running and a temperature of the thermal management fluid is below a lower control limit.

Abstract: A thermal management system for an energy storage system, the energy storage system comprising an energy storage device, an energy storage monitoring system including circuitry dedicated and configured to monitor a temperature of the energy storage device. The thermal management system comprises: a thermal management conditioning loop, a pump configured to circulate a thermal management fluid through the thermal management conditioning loop, a heat source, and a heat transfer hardware in thermal communication with the energy storage device. An energy storage controller of the energy storage monitoring system is configured to confirm that a temperature of the thermal management fluid and/or a temperature of the energy storage device is below an upper safety limit, between a lower control limit and an upper control limit, or both, and in response, to send an enable heater request indicating the heat source is to turn on.

Abstract: An example system includes an electrical energy storage system (ESS) comprising: an upper node and a lower node; a first set of battery modules that are connected in series; a second set of battery modules that are connected in series; a DC/DC converter electrically in series with the first set of battery modules between the upper node and the lower node, wherein the DC/DC converter sources electrical energy from the second set of battery modules; and a controller configured to adjust an output voltage of the DC/DC converter such that a voltage across the upper node and the lower node is maintained at a specified output voltage level.

Abstract: A system includes a first generator configured to output a first plurality of AC signals; a second generator configured to output a second plurality of AC signals; a first set of rectifiers configured to convert the first plurality of AC signals into a first plurality of DC signals for output onto a first DC bus, wherein each of the first set of rectifiers includes a respective contactor configured to de-couple a DC output of the respective rectifier from the first DC electrical bus; and a second set of rectifiers configured to convert the second plurality of AC signals into a second plurality of DC signals for output onto a second DC bus, wherein each of the second set of rectifiers includes a respective contactor configured to de-couple a DC output of the respective rectifier from the second DC bus.

Abstract: An example system includes an electrical energy storage system (ESS) comprising: an upper node and a lower node; a first set of battery modules that are connected in series; a second set of battery modules that are connected in series; a DC/DC converter electrically in series with the first set of battery modules between the upper node and the lower node, wherein the DC/DC converter sources electrical energy from the second set of battery modules; and a controller configured to adjust an output voltage of the DC/DC converter such that a voltage across the upper node and the lower node is maintained at a specified output voltage level.

Abstract: An example system includes an electric machine, an alternating current (AC)/direct current (DC) converter, a Y-capacitor, and a controller. The AC/DC converter being connected to the electric machine and having a DC side and an AC side. The Y-capacitor is located on the DC side of the AC/DC converter. The controller is configured to determine, based on a measurement of the DC side of the AC/DC converter, an occurrence of a ground fault on the AC side of the AC/DC converter, and control, based on the occurrence of the ground fault, operation of the AC/DC converter.

Abstract: A system for providing propulsive electrical power for an aircraft, the system comprising: a first generator configured to output a first plurality of AC electrical signals; a second generator configured to output a second plurality of AC electrical signals; a first set of rectifiers configured to convert the first plurality of AC electrical signals into a first plurality of DC electrical signals for output onto a first DC electrical bus of a plurality of DC electrical busses; and a second set of rectifiers configured to convert the second plurality of AC electrical signals into a second plurality of DC electrical signals for output onto a second DC electrical bus of the plurality of DC electrical busses, wherein each rectifier of the plurality of rectifiers includes a respective controller of a plurality of controllers, and wherein the plurality of controllers are configured to coordinate response to detected faults.

Abstract: A turbo-generator system for generating propulsive electrical power for an aircraft includes an electric machine comprising: a rotor configured to be rotated by a gas-turbine of the turbo-generator system; a stator comprising: a first active section comprising first windings surrounding a first portion of the rotor; and a second active section comprising second windings surrounding a second portion of the rotor.

Abstract: A system includes a first generator configured to output a first plurality of AC signals; a second generator configured to output a second plurality of AC signals; a first set of rectifiers configured to convert the first plurality of AC signals into a first plurality of DC signals for output onto a first DC bus, wherein each of the first set of rectifiers includes a respective contactor configured to de-couple a DC output of the respective rectifier from the first DC electrical bus; and a second set of rectifiers configured to convert the second plurality of AC signals into a second plurality of DC signals for output onto a second DC bus, wherein each of the second set of rectifiers includes a respective contactor configured to de-couple a DC output of the respective rectifier from the second DC bus.

Abstract: In some examples, this disclosure describes a method for detecting a fault in an electrical power system comprising a bus connected between a first solid state power converter and a second solid state power converter. The method includes receiving, at a controller of the electrical power system, a first signal indicating a current at a source side of the first solid state power converter, wherein the source side of the first solid state power converter is connected to a power source of the electrical power system. The method also includes receiving, at the controller, a second signal indicating a current at the bus and determining, by the controller, that a fault occurred in the electrical power system based on the first signal and further based on the second signal. The method further includes controlling the first solid state power converter in response to determining that the fault occurred.

Abstract: In some examples, a system includes an energy storage device configured to deliver power to a bus or receive power from a bus via a power converter. The system also includes a controller configured to determine that a voltage magnitude on the bus is less than a first threshold level in a first instance and cause the energy storage device to deliver power to the bus in response to determining that the voltage magnitude is less than the first threshold level. The controller is also configured to determine that the voltage magnitude on the bus is greater than a second threshold level in the second instance, wherein the second threshold level is greater than a first threshold level and cause the energy storage device to receive power from the bus in response to determining that the voltage magnitude is greater than the second threshold level.

Abstract: In some examples, a system includes a load configured to generate propulsion based on power received from a bus via a power converter. The system also includes a controller configured to determine that a voltage magnitude on the bus is not less than a threshold level in a first instance and cause the power converter to deliver a first magnitude of power to the load in response to determining that the voltage magnitude is not less than the threshold level in the first instance. The controller is also configured to determine that the voltage magnitude on the bus is less than the threshold level in a second instance and cause the power converter to deliver a second magnitude of power to the load in response to determining that the voltage magnitude is less than the threshold level in the second instance, the second magnitude being less than the first magnitude.

Abstract: In some examples, a system includes a bus and a first power converter connected to the bus. The system also includes a second power converter connected to the bus, the second power converter having a topology different from the topology of the first power converter. The system further includes a power source and an energy storage device connected to the bus via the first and second power converters, respectively. In addition, the system includes a source controller configured to control the first power converter and a storage controller configured to control the second power converter. The system also includes a system controller configured to determine a first set point for the first power converter, transmit an indication of the first set point to the source controller, determine a second set point for the second power converter, and transmit an indication of the second set point to the storage controller.

Abstract: An aerospace battery may include a housing; a battery pack core; a ceramic felt surrounding at least part of the battery pack core; and a closed cell foam filling open space between the battery pack core, the ceramic felt, and the housing.

Abstract: A battery housing for an aerospace battery may include a first endplate; a flange; and an elliptical cylinder extending from a first cylinder end to a second cylinder end. The first cylinder end of the elliptical cylinder may be welded to the first endplate, and the second cylinder end of the elliptical cylinder may be welded to the flange. The elliptical cylinder is formed from a sheet of material comprising a first sheet end and a second sheet end. The first sheet end may be welded to the second sheet end at a weld location that runs from the first cylinder end to the second cylinder end at a perimeter location that is calculated to experience a reduced stress during pressurization of the housing.

Abstract: A battery pack core may include a cold plate comprising a plurality of apertures defined between a first major surface and a second major surface of the cold plate; a plurality of battery cells, a single battery cell positioned in each aperture of the plurality of apertures such that a first end of the battery cell projects beyond the first major surface and a second end of the battery cell projects beyond the second major surface; and a plurality of silicone bushings, a silicone bushing surrounding each battery cell of the plurality of battery cells and contacting a wall of the aperture in which the battery cell is positioned.

Abstract: A power conversion system includes a first switch configured to be connected between a first phase of a polyphase alternating current (AC) power source and an electrical load and a first diode configured to be connected between the first phase of the polyphase AC power source and the electrical load, the diode configured to conduct a current from the AC power source to the electrical load. The power conversion system also includes a control unit configured to interface with the first switch to close, responsive to the occurrence of a short circuit fault, the first switch during a negative current portion of the AC cycle of the first phase of the polyphase AC power source and open, responsive to the occurrence of the short circuit fault, the first switch during a positive current portion of the AC cycle of the first phase of the polyphase AC power source.

Abstract: In some examples, a system includes an energy storage device configured to deliver power to a bus or receive power from a bus via a power converter. The system also includes a controller configured to determine that a voltage magnitude on the bus is less than a first threshold level in a first instance and cause the energy storage device to deliver power to the bus in response to determining that the voltage magnitude is less than the first threshold level. The controller is also configured to determine that the voltage magnitude on the bus is greater than a second threshold level in the second instance, wherein the second threshold level is greater than a first threshold level and cause the energy storage device to receive power from the bus in response to determining that the voltage magnitude is greater than the second threshold level.