SURGE AVOIDANCE CONTROL METHOD AND SURGE AVOIDANCE CONTROL DEVICE FOR EXHAUST TURBINE TURBOCHARGER

摘要

A surge avoidance control method of avoiding surging in an exhaust turbocharger which comprises a turbine rotated by exhaust gas from an engine and a compressor rotatably driven by the turbine, by controlling an opening degree of an operation device capable of adjusting an operation point of the compressor between fully open and fully closed, includes: a surge detection step of determining whether the operation point of the compressor is positioned in a surge operation region at each predetermined timing; a surge avoidance opening-degree calculation step of calculating a surge avoidance opening degree of the operation device necessary for moving the operation point of the compressor determined to be positioned in the surge operation region in the surge detection step out of the surge operation region; a correction opening-degree calculation step of calculating a correction opening degree of the operation device on the basis of a moving velocity of the operation point of the compressor which is determined to be positioned in the surge operation region in the surge detection step; and an opening-degree command value calculation step of calculating an opening-degree command value of the operation device on the basis of the surge avoidance opening degree and the correction opening degree.