Temperature inversion detection and mitigation strategies to avoid compressor surge

A system for controlling a plurality of compressor inlet guide vanes of a gas turbine engine in an aircraft, the system comprising:

• an engine data source configured to supply an engine data representative of one or more sensed gas turbine engine parameters;
• and
• an engine control unit configured to implement a compressor inlet guide vane control algorithm, the engine control unit coupled to receive the engine data from the engine data source and an inlet temperature value that is at least representative of a sensed engine inlet total temperature, the engine control unit configured to:
• (i) supply the inlet temperature value to the compressor inlet guide vane control algorithm,
• (ii) process the one or more sensed gas turbine engine parameters to determine an inlet temperature modifier value, the inlet temperature modifier value being an estimate of a difference between the sensed engine inlet total temperature and an actual engine inlet total temperature,
• (iii) add the inlet temperature modifier value to the inlet temperature value to derive a modified engine inlet total temperature,
• (iv) use the modified engine inlet total temperature in the compressor inlet guide vane control algorithm, and
• (v) control the compressor inlet guide vanes using the compressor inlet guide vane control algorithm.

A system, comprising:

• a gas turbine engine including a compressor section and a plurality of compressor inlet guide vanes, the plurality of compressor inlet guide vanes respond to guide vane commands to move to commanded guide vane positions;
• an engine data source in operable communication with the gas turbine engine and configured to supply an engine data representative of one or more sensed gas turbine engine parameters;
• and
• an engine control unit in operable communication with the gas turbine engine and the engine data source and configured to implement a compressor inlet guide vane control algorithm, the engine control unit coupled to receive the engine data from the engine data source and an inlet temperature value that is at least representative of a sensed engine inlet total temperature, the engine control unit configured to:
• (i) supply the inlet temperature value to the compressor inlet guide vane control algorithm,
• (ii) process the one or more sensed gas turbine engine parameters to determine an inlet temperature modifier value, the inlet temperature modifier value being an estimate of a difference between the sensed engine inlet total temperature and an actual engine inlet total temperature,
• (iii) add the inlet temperature modifier value to the inlet temperature value to derive a modified engine inlet total temperature,
• (iv) use the modified engine inlet total temperature in the compressor inlet guide vane control algorithm, and
• (v) control the compressor inlet guide vanes using the compressor inlet guide vane control algorithm.