Patent attributes
In the processing circuit of the control device, the stress of the compressor impeller is acquired every predetermined control cycle. Setting a small section, and calculating a small section average value and a small section amplitude are repeatedly executed. Setting a middle section, and calculating a middle section average value and a middle section amplitude are repeatedly executed. The first damage value is calculated based on the small section average value and the small section amplitude. The second damage value is calculated based on the middle section average value and the middle section amplitude. An estimated value of the deterioration degree of the compressor impeller is calculated based on the integrated value of the first damage value and the second damage value.
