In accordance with at least one aspect of this disclosure, there is provided a system for aircraft power. The system includes a DC/DC converter having a DC input and a DC output and a switching circuit connecting the DC input to the DC output operable to vary voltage at the DC output. A control module is operatively connected to the switching circuit for variable control of the DC output. The control module includes machine readable instructions to cause the control module to receive input indicative of altitude and control the switching circuit to vary voltage of the DC output as a function of environmental conditions such as altitude and humidity. In embodiments the altitude sensor is operatively connected to the controller.

An electrical architecture of an aircraft includes a plurality of primary generators each associated with a propulsion engine of the aircraft, a plurality of primary electrical networks each associated with a primary generator in nominal operating mode, a single-part secondary electrical network, an electrical energy accumulation device connected directly to the secondary network, a first electrical energy converter arranged between the secondary electrical network and a first of the primary electrical networks, allowing energy to be transferred from the first of the primary electrical networks to the secondary electrical network, the first electrical energy converter being intended to supply electrical energy to the electrical energy accumulation device in nominal operating mode, a second electrical energy converter arranged between the secondary electrical network and a second of the primary electrical networks, allowing energy to be transferred from the secondary electrical network to the second of the primary electrical networks.

Provided is a system including: a management unit configured to manage a plurality of battery packs connected in parallel, in which the management unit is configured to control the plurality of battery packs to cause the plurality of battery packs to be discharged alternately so that a discharge rate of each of the plurality of battery packs becomes higher than the discharge rate in a case of discharging all of the plurality of battery packs. The plurality of battery packs include a plurality of left-hand side battery packs and a plurality of right-hand side battery packs, and the management unit is configured to manage the plurality of battery packs to cause at least one of the plurality of battery packs in each of the plurality of left-hand side battery packs and the plurality of right-hand side battery packs to be discharged at a time in order.

A lighter than air airship (1) comprising a gas-filled flexible hull (2) which is elongate with a longitudinal axis (1′) and with a front end (4) and a rear end (5), wherein a harness-structure (3) is abutting an outer side of the hull (2) and not perturbing the hull and not extending through the hull, the harness-structure (3) is made of a bendable material and carries a propeller engine (10) for forward thrust of the airship (1), rechargeable batteries (11) for providing electrical power to the propeller engine (10), and a solar panel for providing electrical power to recharge the batteries (11).

A drive system comprises a DC-DC converter that is arranged to receive an input voltage from a battery having a nominal battery voltage. The DC-DC converter has a first mode of operation in which the DC-DC converter generates a regulated output voltage from the input voltage and supplies the regulated output voltage to a load, and a second mode of operation in which the DC-DC converter is by-passed such that the input voltage from the battery is supplied to the load. A controller is arranged to compare the input voltage to a threshold voltage that is less than the nominal battery voltage. The controller operates the DC-DC converter in the first mode when the input voltage is less than the threshold voltage, and operates the DC-DC converter otherwise.

Described are inerting systems that may be used on board an aircraft or other passenger transportation vehicle to reduce a risk of fire due to electronic components or to other elements in a compartment and to assist in preventing or extinguishing any fire or hazardous condition that may occur. The systems include a source of inert gas such as oxygen depleted air generated from a fuel cell on board the aircraft. The oxygen depleted air or other inert gas is conveyed through ducts to compartments that house the electronics, thus changing the conditions in the compartment to be less conducive to fire.

A power unit for producing both alternating current and direct current includes a switcher connected to a direct current source, wherein the switcher includes circuitry configured to produce both alternating current having first characteristics and direct current having second characteristics, wherein the circuitry comprises a plurality of insulated gate bipolar transistor circuits and drive circuits connected to the insulated gate bipolar transistor circuits. The switcher may receive variable voltage and frequency or constant voltage and frequency. In either case, the switcher circuitry is able to provide power of the desired characteristics. The power unit may be used to power aircraft when the aircraft is on the ground.

An unmanned aerial vehicle comprising at least one rotor motor. The rotor motor is powered by a micro hybrid generation system. The micro hybrid generator system comprises a rechargeable battery configured to provide power to the at least one rotor motor, a small engine configured to generate mechanical power, a generator motor coupled to the small engine and configured to generate AC power using the mechanical power generated by the small engine, a bridge rectifier configured to convert the AC power generated by the generator motor to DC power and provide the DC power to either or both the rechargeable battery and the at least one rotor motor, and an electronic control unit configured to control a throttle of the small engine based, at least in part, on a power demand of at least one load, the at least one load including the at least one rotor motor.

A high voltage electric machine and power distribution system including one or more of such electric machines are provided. In one aspect, a high voltage electric machine includes a stator, a rotor, and a housing encasing at least a portion of the stator and rotor. The stator is modularized into cascaded voltage stator modules. The stator modules are galvanically isolated from one another by intermodular separators. At least one intermodular separator is positioned between each adjacent pair of stator modules. The stator modules are also galvanically isolated from the housing by a housing separator. The housing separator is positioned between the stator modules and the housing. Each stator module has an associated set of windings that are wound only within their associated stator module.

An electric power supply is disclosed having high-voltage, direct-current (HVDC) circuitry comprising one or more DC pre-charge capacitors and one or more power transistor switches, the HVDC circuitry configured to receive high-voltage, direct-current (HVDC) input power of about 320 volts and/or greater and convert the HVDC input power to multi-phase, high-voltage, alternating-current (HVAC) output power of about 320 volts and/or greater; and low-voltage, direct current (LVDC) circuitry adapted and configured to operate on low-voltage, direct-current, wherein the LVDC circuitry is configured to control and monitor the multi-phase HVAC output power. The electric power supply is further configured to operate in reverse and convert received multiphase HVAC input power to HVDC output power.