Compressed air supply system of aircraft

A compressed air supply system of an aircraft,

• the compressed air supply system comprising:
• a bleed air passage through which bleed air from a gas turbine engine flows;
• an auxiliary compressor including a compressor inlet and a compressor outlet, the compressor inlet being fluidly connected to the bleed air passage;
• a supply passage which is fluidly connected to the compressor outlet and through which compressed air from the auxiliary compressor is supplied to an air system of the aircraft;
• a return passage which extends from the supply passage and through which the compressed air from the auxiliary compressor is supplied to the bleed air passage;
• a pressure regulating valve that opens or closes the return passage;
• a driver that rotates the auxiliary compressor;
• a sensor that detects a pressure of the bleed air passage or the supply passage;
• and
• circuitry that controls an output rotational frequency of the driver in accordance with a detection signal of the sensor, wherein
• when an absolute value of a time change rate of the pressure detected by the sensor exceeds a threshold, the circuitry controls an opening degree of the pressure regulating valve such that a pressure fluctuation in the supply passage is suppressed.

A compressed air supply system of an aircraft,

• the compressed air supply system comprising:
• a bleed air passage through which bleed air from a gas turbine engine flows;
• a first auxiliary compressor including a compressor inlet and a compressor outlet, the compressor inlet being fluidly connected to the bleed air passage;
• a supply passage which is fluidly connected to the compressor outlet and through which compressed air from the first auxiliary compressor is supplied to an air system of the aircraft;
• a driver that rotates the first auxiliary compressor;
• a second auxiliary compressor that includes a compressor inlet and a compressor outlet, is connected in parallel with the first auxiliary compressor, and is rotated by the driver, the compressor inlet being fluidly connected to the bleed air passage, the compressor outlet being fluidly connected to the supply passage;
• a switching structure that switches the second auxiliary compressor between a compression state and a non-compression state;
• a sensor that detects a pressure or a temperature of the supply passage;
• and
• circuitry that controls an output rotational frequency of the driver in accordance with a detection signal of the sensor, wherein
• the switching structure includes
• a second return passage that bypasses the second auxiliary compressor and connects the compressor outlet of the second auxiliary compressor to the compressor inlet of the second auxiliary compressor and
• a second pressure regulating valve that opens or closes the second return passage.