Control device and control method

A control device comprising:

• a variation command unit that changes a command value, which is a command value sent to a system including a compressor, affecting an operating state of the compressor;
• a proportional coefficient calculation unit that calculates a proportional coefficient of a variation in a parameter, which indicates a state of the compressor or an electric motor that drives the compressor when the system is operated based on the command value, with respect to the command value;
• and
• a detection unit that detects surging in the compressor based on a value of the proportional coefficient.

A control method comprising:

• changing a command value, which is a command value sent to a system including a compressor, affecting an operating state of the compressor;
• calculating a proportional coefficient of a variation in a parameter, which indicates a state of the compressor or an electric motor that drives the compressor when the system is operated based on the command value, with respect to the command value;
• and
• performing control for avoiding or suppressing surging in the compressor, based on a value of the proportional coefficient.

A non-transitory computer-readable storage medium storing a program for causing a computer to execute a process of:

• changing a command value, which is a command value sent to a system including a compressor, affecting an operating state of the compressor;
• calculating a proportional coefficient of a variation in a parameter, which indicates a state of the compressor or an electric motor that drives the compressor when the system is operated based on the command value, with respect to the command value;
• and
• performing control for avoiding or suppressing surging in the compressor, based on a value of the proportional coefficient.