A control system for charging an aircraft, comprising: a battery pack, an input device configured to enable a user to select between different charging modes, two main contactors connecting the battery pack to an electric propulsion unit (EPU) load and an auxiliary load, a EPU load contactor connecting the battery pack to the EPU load and a controller configured to receive the selected charge mode and control the contactors, keep the two main contactors open upon receiving a user selection to charge in a first mode, close the two main contactors and keep an EPU load contactor open upon receiving a user selection to charge in a second mode, and close the two main contactors and the EPU load contactor upon receiving a user selection to charge in a third mode.

A method for manufacturing a rotor assembly of an electric engine, comprising: loading a first and second plurality of magnets in a magnet insertion tool, loading a sleeve in the magnet insertion tool: performing an insertion movement of the first plurality of magnets with respect to the second plurality of magnets using the magnet insertion tool, wherein the insertion movement comprises: moving the first plurality of magnets in a radial direction of the sleeve; moving the second plurality of magnets in an axial direction of the sleeve; and expanding a radius of the sleeve in the radial direction using the magnet insertion tool during the insertion movement.

A method for manufacturing a rotor assembly of an electric engine, comprising: loading a first and second plurality of magnets in a magnet insertion tool, loading a sleeve in the magnet insertion tool: performing an insertion movement of the first plurality of magnets with respect to the second plurality of magnets using the magnet insertion tool, wherein the insertion movement comprises: moving the first plurality of magnets in a radial direction of the sleeve; moving the second plurality of magnets in an axial direction of the sleeve; and expanding a radius of the sleeve in the radial direction using the magnet insertion tool during the insertion movement.

Provided are a stator, and a propeller driving device and an aircraft using the stator. The propeller driving device includes: a radial gap type BLDC motor with an inner rotor-outer stator structure where a rotor is placed in a circumferential shape with an air gap inside a stator; and a propeller installation bracket for mounting a propeller to a rotary shaft of the motor, wherein the stator includes: a stator core including an annular back yoke having a predetermined width to form a magnetic circuit and teeth extending from the back yoke in a central direction; an insulator formed to surround an outer circumferential surface on which a coil is wound in each tooth; and a stator coil wound around an outer circumferential surface of the insulator in each tooth. The insulator is formed of an insulating heat dissipation composite material having both heat dissipation performance and insulation performance.

Provided are a stator, and a propeller driving device and an aircraft using the stator. The propeller driving device includes: a radial gap type BLDC motor with an inner rotor-outer stator structure where a rotor is placed in a circumferential shape with an air gap inside a stator; and a propeller installation bracket for mounting a propeller to a rotary shaft of the motor, wherein the stator includes: a stator core including an annular back yoke having a predetermined width to form a magnetic circuit and teeth extending from the back yoke in a central direction; an insulator formed to surround an outer circumferential surface on which a coil is wound in each tooth; and a stator coil wound around an outer circumferential surface of the insulator in each tooth. The insulator is formed of an insulating heat dissipation composite material having both heat dissipation performance and insulation performance.

A power distribution system for an aircraft, comprising: a plurality of electric propeller units (EPUs), a first paired battery pack unit, the first paired battery pack unit, and a second paired battery pack unit. The first paired battery pack unit may include a first battery electrically connected to a second battery via a first high voltage bus. The first battery may be configured to provide power to a first set of EPUs of the plurality of EPUs, the second battery may be configured to provide power to a second set of EPUs of the plurality of EPUs, the first battery may be configured to act as a backup battery for powering the second set of EPUs, and the first high voltage bus and the second high voltage bus may be electrically separate from one another.

A power distribution system for an aircraft, comprising: a plurality of electric propeller units (EPUs), a first paired battery pack unit, the first paired battery pack unit, and a second paired battery pack unit. The first paired battery pack unit may include a first battery electrically connected to a second battery via a first high voltage bus. The first battery may be configured to provide power to a first set of EPUs of the plurality of EPUs, the second battery may be configured to provide power to a second set of EPUs of the plurality of EPUs, the first battery may be configured to act as a backup battery for powering the second set of EPUs, and the first high voltage bus and the second high voltage bus may be electrically separate from one another.

Embodiments are provided for charging system for an aircraft. The charging system may comprise a plurality of electric propeller units (EPUs), a plurality of battery packs configured to power the plurality of EPUs, a charge control unit configured to determine a target charge level for each of the plurality of battery packs, receive charge status information from each of the plurality of battery packs, and upon determining that a target charge level of at least one of the battery packs has been reached, command the at least one battery pack to disconnect from a common charging bus having a high voltage connection to a power source external to the aircraft.

Embodiments are provided for charging system for an aircraft. The charging system may comprise a plurality of electric propeller units (EPUs), a plurality of battery packs configured to power the plurality of EPUs, a charge control unit configured to determine a target charge level for each of the plurality of battery packs, receive charge status information from each of the plurality of battery packs, and upon determining that a target charge level of at least one of the battery packs has been reached, command the at least one battery pack to disconnect from a common charging bus having a high voltage connection to a power source external to the aircraft.