Abstract: Systems and methods for current ripple reduction for a direct current (DC) source powering an alternating current (AC) load. In accordance with one embodiment, the system and method involve interleaved operation of a 3×3-phase AC motor having multiple groups of windings. In accordance with another embodiment, the system and method involve interleaved operation of multiple co-shafted 3-phase AC motors. In accordance with a further embodiment, the system and method involve interleaved operation multiple 3-phase AC motors (not co-shafted) of the same level of power. The interleaved operation entails interleaved switching inside a set of inverters which are connected in parallel between a DC bus and the windings of the AC motor (motors).

Abstract: Systems and methods for current ripple reduction for a direct current (DC) source powering an alternating current (AC) load. In accordance with one embodiment, the system and method involve interleaved operation of a 3×3-phase AC motor having multiple groups of windings. In accordance with another embodiment, the system and method involve interleaved operation of multiple co-shafted 3-phase AC motors. In accordance with a further embodiment, the system and method involve interleaved operation multiple 3-phase AC motors (not co-shafted) of the same level of power. The interleaved operation entails interleaved switching inside a set of inverters which are connected in parallel between a DC bus and the windings of the AC motor (motors).

Abstract: A method for managing power in an airplane. Power quality data and load management data are collected from airplane systems in the airplane at a variable sampling rate using data collectors assigned to the airplane systems in which the variable sampling rate increases in response to a selected trigger event. The power quality data and the load management data are received by a power monitor from the data collectors during phases of flight for the airplane. A group of load management operations for the airplane systems are performed by a load manager in the airplane during operation of the airplane. The group of load management operations is performed using the power quality data and the load management data received from the data collectors during the phases of flight for the airplane.

Abstract: An electrical power system for regenerative loads may include a DC bus and an electrical actuator load, where back-driving the electrical actuator load generates regenerative electrical energy, and where the electrical actuator load is configured to transmit the regenerative electrical energy to the DC bus. The system may also include at least one additional load, where at least a portion of the regenerative electrical energy is transmitted to the at least one additional load.

Abstract: An aircraft may include at least one secondary power system requiring secondary power, at least two main engines, and at least three non-propulsive utility power (NPUP) generation systems. The NPUP generation systems may each be configured to provide full-time secondary power during operation of the aircraft. The NPUP generation systems may be configured to provide at least a portion of the secondary power required by the secondary power system.

Abstract: A battery and related methods are described. The battery can include a plurality of battery cell segments. Each of the battery cell segments can include an anode segment, a cathode segment, and one or more current limiters. The one or more current limiters are configured to conditionally electrically isolate the battery cell segment based on an occurrence of a short circuit within the battery cell segment. The battery can be used to store electrical power and/or provide electrical power to a load.

Abstract: A battery and related methods are described. The battery can include a plurality of battery cell segments. Each of the battery cell segments can include: a positive temperature coefficient (PTC) material whose resistance increases with temperature, an anode segment, a cathode segment, and one or more current limiters. The one or more current limiters of a battery cell segment are configured to conditionally electrically isolate the battery cell segment based on an occurrence of a short circuit within the battery cell segment. The battery can be used to store electrical power and/or provide electrical power to a load.

Abstract: A battery and related methods are described. The battery can include a plurality of battery cell segments. Each of the battery cell segments can include an anode segment, a cathode segment, and one or more current limiters. The one or more current limiters are configured to conditionally electrically isolate the battery cell segment based on an occurrence of a short circuit within the battery cell segment. The battery can be used to store electrical power and/or provide electrical power to a load.

Abstract: A battery and related methods are described. The battery can include a plurality of battery cell segments. Each of the battery cell segments can include: a positive temperature coefficient (PTC) material whose resistance increases with temperature, an anode segment, a cathode segment, and one or more current limiters. The one or more current limiters of a battery cell segment are configured to conditionally electrically isolate the battery cell segment based on an occurrence of a short circuit within the battery cell segment. The battery can be used to store electrical power and/or provide electrical power to a load.

Abstract: A solid-state high-voltage direct-current (HVDC) bus voltage controller to provide active power flow control in a hybrid electric aircraft power supply system. The HVDC bus voltage controller includes an active voltage controller and an active rectifier unit configured to control the HVDC bus voltage using the PWM control technique. In one implementation, the active rectifier unit includes high-power and high-frequency semiconductor switches with fast turn-off capabilities. The active voltage controller sends an HVDC bus reference voltage to the active rectifier unit. The low-level controller inside the active rectifier unit is configured to control the HVDC bus voltage to match the HVDC bus reference voltage.

Abstract: A programmable alternating current (AC) load in communication with an equipment under test (EUT) is disclosed, where the EUT generates an equipment under test voltage. The programmable AC load includes an active load profiler (ALP) for creating current modulation load profiles that are sent to the EUT. The ALP includes a voltage source inverter, a control module in operative communication with the voltage source inverter of the ALP, and a grid-connected inverter having an AC side and a direct current (DC) side. The AC side of the voltage source inverter is in communication with the EUT for receiving the equipment under test voltage. The control module sends a control duty signal to the voltage source inverter indicating a switching frequency and a duty cycle of the current modulation load profiles.

Abstract: An EMI filter network may be used to provide interference filtering for multiple loads (referred to collectively as a dynamic load). In one aspect, the EMI filter network includes electrical switches that establish different configurations or arrangements of passive circuit elements (e.g., inductors and capacitors) where each configuration generates a different filter value. The EMI filter network may be communicatively coupled to a controller which changes the configuration of the EMI filter network using the switches in response to the dynamic load changing operational states. For example, each configuration of the EMI filter network may correspond to one of the operational states of the dynamic load. Thus, as the operational state of the dynamic load changes—e.g., different motors become operational—the controller alters the configuration of the EMI filter network to provide a filter value that corresponds to the current operational state of the dynamic load.

Abstract: A method and apparatus for providing regulated direct current power for a direct current load on an aircraft. A regulated transformer rectifier unit on an aircraft comprises a plurality of converter modules connected in parallel between an input and an output. Each converter module in the plurality of converter modules comprises a transformer rectifier unit. The plurality of converter modules are controlled by a controller to provide regulated direct current power at the output from alternating current power provided at the input from an alternating current power source on the aircraft.

Abstract: An electrical power system for regenerative loads may include a DC bus and an electrical actuator load, where back-driving the electrical actuator load generates regenerative electrical energy, and where the electrical actuator load is configured to transmit the regenerative electrical energy to the DC bus. The system may also include at least one additional load, where at least a portion of the regenerative electrical energy is transmitted to the at least one additional load.

Abstract: Systems and methods are provided for an aircraft propulsor configured to generate electrical power through a variable frequency generator in response to rotation of a gear train. The aircraft propulsor includes compensation circuitry. The aircraft propulsor further includes exciter circuitry that, when powered by an excitation signal, generates a magnetic field that interacts with a rotating variable frequency generator to generate electrical power. The exciter circuitry may be powered by at least a portion of the power generated by the variable frequency generator. The compensation circuitry may adjust the excitation signal to reduce the effect of torsional oscillation of the gear train and/or the variable frequency generator on the quality of power produced by the variable frequency generator.

Abstract: A multi-phase autotransformer (10) is disclosed. The exemplary transformer includes primary windings PWA, PWB, PWC) and secondary windings (SWA1-SWA4, SWB1-SWB4, SWC1-SWC4). The primary windings are connected in a delta configuration and to a three-phase input voltage source. Each secondary winding is electrically connected to a primary winding but is magnetically coupled to a different primary winding. Three sets of secondary windings provide three three-phase outputs (350A, 350B, 350C), each of which has a voltage which is less than the three-phase input voltage, the three-phase output of each set being phase-shifted with respect to the other sets. These three sets also, collectively, provide a multi-phase output (325). Another set of secondary windings, in conjunction with the input voltage, provides another multi-phase phase output (360) which has approximately the same voltage as the three-phase input voltage.

Abstract: A programmable alternating current (AC) load in communication with an equipment under test (EUT) is disclosed, where the EUT generates an equipment under test voltage. The programmable AC load includes an active load profiler (ALP) for creating current modulation load profiles that are sent to the EUT. The ALP includes a voltage source inverter, a control module in operative communication with the voltage source inverter of the ALP, and a grid-connected inverter having an AC side and a direct current (DC) side. The AC side of the voltage source inverter is in communication with the EUT for receiving the equipment under test voltage. The control module sends a control duty signal to the voltage source inverter indicating a switching frequency and a duty cycle of the current modulation load profiles.

Abstract: A method for managing power in an airplane. Power quality data and load management data are collected from airplane systems in the airplane at a variable sampling rate using data collectors assigned to the airplane systems in which the variable sampling rate increases in response to a selected trigger event. The power quality data and the load management data are received by a power monitor from the data collectors during phases of flight for the airplane. A group of load management operations for the airplane systems are performed by a load manager in the airplane during operation of the airplane. The group of load management operations is performed using the power quality data and the load management data received from the data collectors during the phases of flight for the airplane.

Abstract: An aircraft may include at least one secondary power system requiring secondary power, at least two main engines, and at least three non-propulsive utility power (NPUP) generation systems. The NPUP generation systems may each be configured to provide full-time secondary power during operation of the aircraft. The NPUP generation systems may be configured to provide at least a portion of the secondary power required by the secondary power system.

Abstract: A programmable AC load in communication with an equipment under test (EUT) is disclosed. The EUT generates an equipment under test voltage. The programmable alternating current (AC) load includes an active load profiler (ALP), a grid-connecter inverter, and an operational mode selector. The operational mode selector is in communication with an AC side of the grid-connected inverter. The operational mode selector places the programmable AC load in either a regenerative mode where the equipment under test voltage is sent to a main grid or a dissipative mode where the equipment under test voltage is dissipated by heat.