Patent ID: 11878594
Assignee: THE BOEING COMPANY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC B  H  G  Y | IPC B  G

Claim 0:
1. A method for protecting an electric propulsion system, the method comprising:
(a) sensing a first current supplied by a battery pack at a first end of a protection zone that includes at least a portion of a power line that is connected to receive current from the battery pack and supply current to a motor controller;
(b) sensing a second current supplied to the motor controller at a second end of the protection zone;
(c) receiving sensor data representing a magnitude of the first current sensed in step (a);
(d) receiving sensor data representing a magnitude of the second current sensed in step (b);
(e) calculating a current difference equal to a difference between the magnitude of the first current and the magnitude of the second current;
(f) determining that the current difference exceeds a difference threshold indicating a fault in the protection zone;
(g) commanding the electric propulsion system to operate in a mode that isolates the fault in response to step (f); and
(h) operating the electric propulsion system in a mode that isolates the fault,
wherein steps (c) through (g) are performed by a differential protection control module, and
wherein step (h) comprises changing states of power switches in the motor controller to short an AC motor connected to the motor controller, thereby blocking current regenerated by the AC motor from reaching the power line.