Bleed-off valve drive controller for aircraft gas turbine engine

A bleed-off valve drive controller for an aircraft gas turbine engine equipped with at least:

• a single spool compressor and turbine which obtains thrust from output generated by driving the turbine with high-temperature, high-pressure gas produced by combusting fuel with compressor-compressed intake air in a combustion chamber;
• a bleed-off valve that bleeds intake air compressed by the compressor exterior;
• an electric actuator that drives the bleed-off valve to open or close when current is supplied;
• and
• an electronic control unit that controls supply of current to the electric actuator;
• wherein the electronic control unit is constituted of a microcomputer equipped with at least a processor and a memory coupled to the processor, and the processor is configure to:
• calculate a required valve opening θr required under operating condition of the engine and a current value Ia corresponding to the required valve opening θr, and instruct current supply to the electric actuator based on the calculated current value Ia so as to bring opening θ of the bleed-off valve to the calculated required opening θr;
• compare the current value Ia with a predetermined current value Ib, estimate that the bleed-off valve has failed if the current value Ia exceeds the predetermined current value 1b, calculate a current value Ic when the bleed-off valve is estimated to have failed and instruct current supply to the electric actuator based on the calculated current Ic so as to enlarge opening θ of the bleed-off valve toward wide-open opening θw;
• calculate a current value Id and instruct current supply to the electric actuator based on the calculated current value Id so as to decrease opening θ of the bleed-off valve from wide-open opening θw toward the calculated required opening θr;
• and
• compare the supplied current value Id with a predetermined current value Ib and determine the bleed-off valve normal when the supplied current value Id is equal to or smaller than the predetermined current value 1b.

A method for controlling a bleed-off valve drive controller for an aircraft gas turbine engine equipped with at least a single spool compressor and turbine which obtains thrust from output generated by driving the turbine with high-temperature, high-pressure gas produced by combusting fuel with compressor-compressed intake air in a combustion chamber;

• the bleed-off valve that bleeds intake air compressed by the compressor exterior;
• and
• an electric actuator that drives the bleed-off valve to open or close when current is supplied;
• comprising the steps of:
• calculating a required valve opening θr required under operating condition of the engine and a current value Ia corresponding to the required valve opening θr, and instructing current supply to the electric actuator based on the calculated current value Ia so as to bring opening θ of the bleed-off valve to the calculated required opening θr;
• comparing the current value Ia with a predetermined current value Ib, estimating that the bleed-off valve has failed if the current value Ia exceeds the predetermined current value 1b, calculating a current value Ic when the bleed-off valve is estimated to have failed and instructing current supply to the electric actuator based on the calculated current Ic so as to enlarge opening θ of the bleed-off valve toward wide-open opening θw;
• calculating a current value Id and instruct current supply to the electric actuator based on the calculated current value Id so as to decrease opening θ of the bleed-off valve from wide-open opening θw toward the calculated required opening θr;
• and
• comparing the supplied current value Id with a predetermined current value Ib and determining the bleed-off valve normal when the supplied current value Id is equal to or smaller than the predetermined current value 1b.