System and method for overspeed detection and protection in an engine
An engine includes a gearbox coupled to a first element and a second element. The engine may include a first speed sensor positioned on an input side of the gearbox, the first speed sensor operable to detect a first speed of the first element. The engine may further include a second speed sensor positioned on an output side of the gearbox, the second speed sensor operable to detect a second speed of the second element. The engine includes a controller comprising a processor and a memory coupled to the processor. The processor may be configured to receive data from the first speed sensor and the second speed sensor. The processor is also configured to detect a trigger event based on the data from the first speed sensor and the data from the second speed sensor. Upon detecting the trigger event, the processor communicates a command to an engine operational system.
1 . A gas turbine engine, comprising:
a gearbox coupled to a first element and a second element;
a first speed sensor positioned on an input side of the gearbox, the first speed sensor operable to detect a first speed of the first element;
a second speed sensor positioned on an output side of the gearbox, the second speed sensor operable to detect a second speed of the second element; and
a control system comprising a processor and a memory coupled to the processor, the processor configured to:
receive data from the first speed sensor; receive data from the second speed sensor;
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.
2 . The gas turbine engine of claim 1 , wherein the first element is an input shaft of the gearbox or a component coupled thereto, and wherein the second element is an output shaft of the gearbox or a component coupled thereto.
3 . The gas turbine engine of claim 2 , wherein the input shaft is a high-speed shaft, and wherein the output shaft is a low-speed shaft.
4 . The gas turbine engine of claim 1 , wherein the trigger event is at least one of:
exceeding a threshold difference between the first speed and the second speed; or
exceeding a threshold rate of change between the first speed and the second speed.
5 . The gas turbine engine of claim 1 , wherein the command is configured to stop the gas turbine engine.
6 . The gas turbine engine of claim 1 , wherein one or more of the first speed sensor or the second speed sensor comprises a variable reluctance sensor, a surface acoustic wave (SAW) sensor, a blade beta angle sensor, or an electrical machine.
7 . The gas turbine engine of claim 1 , wherein the processor is further configured to:
detect a first trigger event upon the divergence exceeding a first threshold; and
detect a second trigger event upon the divergence exceeding a second threshold, wherein the first trigger event prompts the processor to communicate a command to slow the gas turbine engine, and wherein the second trigger event prompts the processor to communicate a command to stop the gas turbine engine.
8 . 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.
9 . The control system of claim 8 , wherein the first element is an input shaft coupled to the gearbox or a component coupled thereto, and wherein the second element is an output shaft of the gearbox or a component coupled thereto.
10 . The control system of claim 9 , wherein the input shaft is a high-speed shaft, and wherein the output shaft is a low-speed shaft.
11 . The control system of claim 8 , wherein the trigger event is at least one of:
exceeding a threshold difference between the first speed and the second speed; or
exceeding a threshold rate of change between the first speed and the second speed.
12 . The control system of claim 8 , wherein the command is configured to stop the gas turbine engine.
13 . 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.
14 . The method of claim 13 , wherein the first element is an input shaft of the gearbox or a component coupled thereto, and wherein the second element is an output shaft of the gearbox or a component coupled thereto.
15 . The method of claim 13 , wherein the command is configured to stop the engine.
16 . The method of claim 13 , further comprising:
determining a relationship between the first speed and the second speed; and
detecting the trigger event upon the relationship exceeding a threshold.
17 . The method of claim 13 , further comprising: determining a rate of change of the first speed; determining a rate of change of the second speed;
determining a relationship between the rate of change of the first speed and the rate of change of the second speed; and
detecting the trigger event upon the relationship exceeding a threshold.
18 . The method of claim 13 , further comprising:
determining a relationship between the first speed and the second speed;
determining a rate of change in the relationship; and
detecting the trigger event upon the rate of change in the relationship exceeding a threshold.
19 . The method of claim 13 , further comprising: determining a rate of change of the first speed; determining a rate of change of the second speed;
determining a relationship between the rate of change of the first speed and the rate of change of the second speed;
determining a rate of change of the relationship; and
detecting the trigger event upon the rate of change of the relationship exceeding a threshold.
20 . The method of claim 13 , further comprising determining a known relationship between the first speed and the second speed based on a reduction ratio of the gearbox, wherein detecting the trigger event comprises detecting the trigger event upon the divergence exceeding a threshold based on the known relationship.