Patent ID: 11933291
Assignee: HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  G  H | IPC F  G  H

Claim 10:
11. A method of monitoring a compressor including a motor, a compressor body that compresses a gas by being driven by the motor, a pressure sensor that is provided on a discharge side of the compressor body and senses a pressure of the compressed gas, at least one controller having a functionality of switching between load running and no-load running on a basis of the pressure sensed by the pressure sensor and a functionality of controlling power to be supplied to the motor via a circuit that has a semiconductor element, and a first temperature sensor that senses a temperature of the semiconductor element, the method comprising:
calculating a relative temperature of the semiconductor element relative to a reference temperature by using the temperature sensed by the first temperature sensor at time of switching of the compressor from no-load running to load running; and
calculating an amount of change in a remaining lifetime of the semiconductor element corresponding to the relative temperature of the semiconductor element, whereby the remaining lifetime of the semiconductor element is monitored.