Electronic overspeed protection system and method

A method for providing overspeed protection for a gas turbine engine, the gas turbine engine having an engine shaft, the method comprising:

• monitoring, via an overspeed protection system, a torque of the engine shaft;
• determining, via the overspeed protection system, a speed condition of the engine shaft;
• evaluating whether a torque conditional is satisfied based upon the torque of the engine shaft and a torque threshold, the engine conditional being satisfied when the torque of the engine exceeds the torque threshold;
• evaluating whether an overspeed conditional is satisfied based upon the speed condition of the engine shaft and a speed threshold, the speed conditional being satisfied when the speed condition of the engine shaft exceeds the speed threshold;
• determining, via the overspeed protection system, that an overspeed condition is present within the gas turbine engine when both the torque conditional is satisfied and the speed conditional is satisfied, the overspeed condition being indicative of an above normal rotational speed of the engine shaft;
• and
• initiating a shutdown procedure for the gas turbine engine in response to the determined overspeed condition to reduce the rotational speed of the engine shaft.

An overspeed protection system for providing overspeed protection for a gas turbine engine, the gas turbine engine having an engine shaft, the overspeed protection system comprising:

• at least one torque sensor;
• a controller communicatively coupled to the at least one torque sensor, the controller comprising at least one processor, the at least one processor configured to perform a plurality of operations, the plurality of operations comprising:
• monitoring a torque of the engine shaft;
• determining at least one additional condition of the engine shaft;
• receiving an engine shutdown command;
• as a result of receiving the engine shutdown command, changing a torque threshold from a first torque threshold value to a second torque threshold value to test the overspeed protection system, the second torque threshold value higher than the first torque threshold value;
• and
• determining an overspeed condition of the gas turbine engine as a result of the torque of the engine shaft being below the second torque threshold value of the torque threshold and the at least one additional condition of the engine shaft is indicative of the gas turbine engine being in an operational state, the overspeed condition being indicative of an above normal rotational speed of the engine shaft;
• and
• initiating a shutdown procedure for the gas turbine engine in response to the determined overspeed condition to reduce the rotational speed of the engine shaft.