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 rotor assembly includes a plurality of segmented magnets disposed about an outer surface of a rotor core and a plurality of segmented metallic bands configured to secure the plurality of segmented magnets to the outer surface of the rotor core. The number of segments of the segmented metallic bands in an axial direction is greater than the number of segments of the segmented magnets.

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 aerospace battery may include a housing, a retaining seat disposed in the housing, and a battery pack core supported by the retaining seat in the housing. The battery pack core may include at least one cell district comprising a plurality of pouch cell batteries and at least one flexible cold plate disposed between at least two adjacent pouch cell batteries of the plurality of pouch cell batteries. The retaining seat may define a fluid delivery channel configured to couple to an inlet of a cooling channel of the flexible cold plate and a fluid return channel configured to couple to an outlet of the cooling channel of the flexible cold plate.

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 rotor assembly includes a plurality of segmented magnets on an outer surface of a rotor core, a metallic layer on the outer surface of the plurality of segmented magnets, and a plurality of segmented metallic bands on the outer surface of the metallic layer. The plurality of segmented metallic bands is configured to secure the plurality of segmented magnets to the outer surface of the rotor core, and each band of the plurality of metallic bands has an axial length less than an axial length of the rotor.

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: 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: A bi-directional direct current (DC) solid state power controller (SSPC) architecture and control method. The SSPC protects a DC distribution system by isolating both the positive and negative buses independently in case of short circuit or ground fault. The SSPC architecture includes two self-heal interleaved capacitors and includes a fast, soft-charging control technique that provides line-isolated charging of the DC bulk capacitor to avoid inrush current when powering up the DC distribution system. The soft-charging function alternately charges one of the two interleaved capacitors, while the other capacitor discharges to the DC bulk capacitor. Repetitive switching results in a charging and discharging process that increases the voltage of the DC bulk capacitor prior to powering up the DC distribution system, while keeping the DC power source isolated from the load.

Abstract: Energy storage systems for aircraft and methods of operating the same are provided. The energy storage system may include a main battery, a propulsion power bus, a non-critical bus, a critical bus, and an engine starter bus. The propulsion power bus may be configured to convey electricity, which is supplied by the main battery, to an electric propulsion machine configured to provide propulsion for the aircraft. The non-critical bus may be configured to convey electricity to a hotel load on the aircraft. The critical bus may be configured to convey electricity, which is supplied by the main battery, to a critical load on the aircraft. The engine starter bus may be configured to convey electricity, which is supplied by the main battery, to an electric starter for a gas turbine engine, where the gas turbine engine is configured to power the electric propulsion machine.

Abstract: In some examples, an electrical power system includes a differential bus including a high-side rail and a low-side rail, a power source configured to generate power, and a bulk capacitor coupled between the high-side rail and the low-side rail, the bulk capacitor configured to filter the power generated by the power source. The electrical power system also includes a converter configured to convert the power filtered by the bulk capacitor and a pre-charging circuit comprising one or more switches and a middle capacitor, the pre-charging circuit configured to pre-charge the bulk capacitor.

Abstract: Energy storage systems for aircraft and methods of operating the same are provided. The energy storage system may include a main battery, a propulsion power bus, a non-critical bus, a critical bus, and an engine starter bus. The propulsion power bus may be configured to convey electricity, which is supplied by the main battery, to an electric propulsion machine configured to provide propulsion for the aircraft. The non-critical bus may be configured to convey electricity to a hotel load on the aircraft. The critical bus may be configured to convey electricity, which is supplied by the main battery, to a critical load on the aircraft. The engine starter bus may be configured to convey electricity, which is supplied by the main battery, to an electric starter for a gas turbine engine, where the gas turbine engine is configured to power the electric propulsion machine.