Control device that detects surging
A control device includes: 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 control unit that performs control for avoiding or suppressing surging in the compressor, based on a value of the proportional coefficient.
1 . A control device comprising:
a central processing unit (CPU) that:
changes a command value that is sent to a system including a compressor and affects an operating state of the compressor,
calculates a proportional coefficient of a variation in a parameter that 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
performs control for avoiding or suppressing surging in the compressor, based on a value of the proportional coefficient, wherein
the command value is a rotation speed command value of the compressor, and
the CPU further:
changes the rotation speed command value on a time basis during each cycle of the compressor,
calculates the proportional coefficient when the rotation speed command value is changed, and
performs control for increasing a flow rate of fluid sucked and discharged by the compressor, according to a magnitude of the proportional coefficient.
2 . The control device according to claim 1 , wherein the parameter is one of multiple different parameters, and
the CPU further:
calculates the proportional coefficient for each of a plurality of the parameters, and
performs control for avoiding or suppressing surging in the compressor, based on values of a plurality of the proportional coefficients.
3 . The control device according to claim 1 , wherein
the parameter is at least one of a rotation speed of the compressor, vibration of the compressor, a current flowing through the compressor, the flow rate of fluid sucked and discharged by the compressor, pressure of the fluid, a pressure ratio of the fluid before and after the compressor, a rotation speed of the electric motor, vibration of the electric motor, a current flowing through the electric motor, power consumed by the electric motor, and periphery noise.
4 . A control device comprising:
a central processing unit (CPU) that:
changes a command value that is sent to a system including a compressor and affects an operating state of the compressor,
calculates a proportional coefficient of a variation in a parameter that 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
detects surging in the compressor based on a value of the proportional coefficient, wherein
the command value is a rotation speed command value of the compressor, and
the CPU further:
periodically changes the rotation speed command value on a time basis during each cycle of the compressor,
calculates the proportional coefficient when the rotation speed command value is changed, and
detects the surging in the compressor according to a magnitude of the proportional coefficient.