Systems and method for fault protection

A protection system for an electrical power distribution network of an aircraft, the electrical power distribution network including one or more electrical sources connected to one or more electrical loads through a power distribution system, the power distribution system connected to an electrical ground of the aircraft by a high impedance grounding circuit, the protection system comprising:

• an electrical wiring interconnection system separating positive power lines and negative power lines of the power distribution system for reducing line-to-line faults;
• a plurality of protection devices coupled to the power distribution system, wherein a first subset of the plurality of protection devices are coupled electrically upstream of the high impedance grounding circuit and a second subset of the plurality of protection devices are coupled electrically downstream of the high impedance grounding circuit;
• a ground fault detector operably connected to the high impedance grounding circuit and to the electrical ground;
• and
• a controller coupled to the power distribution system, the high impedance grounding circuit, the plurality of protection devices, the ground fault detector, and at least one current sensor, the controller configured to:
• receive input from the at least one current sensor and/or the ground fault detector;
• determine a fault state associated with the electrical power distribution network based on the received input, the fault state comprising no faults, a line-to-line fault or a line-to-ground fault;
• and
• send a trip signal to selectively open or close the first subset or the second subset of the plurality of protection devices when the fault state indicates the line-to-line fault or the line-to-ground fault.

A method of responding to faults in an electrical power distribution network of an aircraft, the electrical power distribution network including a power distribution system grounded through a high impedance grounding circuit, and a plurality of protection devices, the method comprising:

• receiving a current measurement from at least one current sensor and/or a voltage measurement from at least one voltage sensor, wherein the voltage measurement includes a first voltage value between a positive power line and electrical ground and a second voltage value between a negative power line and ground;
• determining a fault state associated with the electrical power distribution network based on the current measurement and/or the voltage measurement, the fault state comprising no faults, a line-to-line fault, or a line-to-ground fault;
• and
• sending a trip signal to selectively open or close a first subset or a second subset of the plurality of protection devices when the fault state indicates the line-to-line fault or the line-to-ground fault;
• wherein the fault state indicates a line-to-line fault when the current measurement exceeds a predetermined threshold;
• and
• wherein the fault state indicates a line-to-ground fault when a difference between the first voltage value and the second voltage value of the voltage measurement exceeds a predetermined threshold.