System and method for overspeed detection and protection in an engine

A control system for a gas turbine engine, the control system comprising:

• a memory;
• and
• a processor coupled to the memory, the processor configured to:
• receive data from a first speed sensor operable to detect a first speed of a first element coupled to a gearbox of the gas turbine engine, the first speed sensor positioned on an input side of the gearbox;
• receive data from a second speed sensor operable to detect a second speed of a second element coupled to the gearbox, the second speed sensor positioned on an output side of the gearbox;
• detect a trigger event based on the data from the first speed sensor and the data from the second speed sensor, the trigger event comprising a divergence between the first speed and the second speed that is indicative of an overspeed condition of the gas turbine engine;
• and
• upon detecting the trigger event, communicate a command to an engine operational system to operate a valve that dumps compressor discharge air pressure or to operate a variable turbine inlet vane to control air flow to a turbine of the gas turbine engine.

A method, comprising:

• sensing a first speed of a first element from a first speed sensor positioned on an input side of a gearbox in an engine;
• receiving data on a second speed of a second element from a second speed sensor positioned on an output side of the gearbox;
• detecting a trigger event based on the first speed and the second speed, the trigger event comprising a divergence between the first speed and the second speed that is indicative of an overspeed condition of the engine;
• and
• upon detecting the trigger event, communicating a command to an engine operational system to operate a valve that dumps compressor discharge air pressure, or to operate a variable turbine inlet vane to control air flow to a turbine of the engine.