A control system is provided to optimize a compressor that has a variable guide vane position and a variable speed set point. One or more controllers receive a process set point for a main process variable for a first performance control application and a deviation set point for a surge deviation level for a second performance control application. The first performance control application operates a first independent primary control loop to control the main process variable at the process set point by manipulating the variable guide vane position. The second performance control application operates a second independent primary control loop to control a surge deviation level at the deviation set point by manipulating the variable speed set point. The second performance control application also executes a limit control loop to limit the main process variable at a limit set point by manipulating the variable speed set point.

A compressor is provided. The compressor according to the present disclosure includes: one or more impellers suctioning and compressing refrigerant; a motor rotating the impeller; a rotation shaft to which the impeller and the motor are connected; a gap sensor measuring a displacement change of the rotation shaft as a frequency change; a temperature compensation sensor determining a frequency compensation value according to a temperature change around the gap sensor; and a control unit calculating a displacement amount of the rotation shaft by reflecting the frequency compensation value provided by the temperature compensation sensor and the frequency change measured by the gap sensor.

Pneumatic air systems for use onboard aircraft include a compressor configured to receive air from an air supply and increase a pressure of said received air to generate compressed air, a heat exchanger configured to receive the compressed air as a first working fluid and a treating air as a second working fluid, the heat exchanger configured to convert the compressed air to compressed and temperature treated air, one or more aircraft systems configured to receive the compressed and temperature treated air, and a surge prevention circuit arranged to prevent surge of air at the compressor, wherein the surge prevention circuit comprises a mechanical valve that is actuated based on a detected pressure within a sense line operably coupled to the mechanical valve.

A compressor control apparatus includes a rectifier configured to rectify AC power to DC power; an inverter including a plurality of switching elements, configured to convert the DC power into a three-phase voltage according to a pulse width modulation (PWM) signal applied to the plurality of switching elements; a motor configured to receive a three-phase current based on the three-phase voltage; a current detector configured to detect a sum of a first phase current, a second phase current, and a third phase current supplied to the motor; and a controller configured to differently determine a duty ratio of the PWM signal applied to each of the plurality of switching elements, and to determine the first phase current, the second phase current, and the third phase current, respectively, based on the determined duty ratio and the sum of the currents detected from the current detector.

A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit. A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

The purpose of the present invention is to provide a gas compressor capable of reducing variation in discharge pressure through control of the number of compressor bodies and a control method for the gas compressor. In order to solve the problem, this gas compressor includes a plurality of compressor units each having a compressor body, a motor for driving the compressor body, and an inverter for controlling a rotational speed of the motor, and a control device for controlling the inverters. Discharge pipes of the compressor bodies converge on one main discharge pipe. A drive frequency of the motor of each compressor body is controlled by the corresponding inverter, whereby a pressure of each discharge pipe is controlled and a discharge pressure of the main discharge pipe is controlled. When the discharge pressure of the main discharge pipe has increased in a period of reduction in the drive frequency of the motor of the compressor body before the drive frequency reaches a lower-limit frequency, the control device calculates a prediction time for reaching a stopping pressure. The control device stops one of the compressor bodies when the prediction time is less than a threshold value.

The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

A control method for a centrifugal compressor and an air conditioning system. The control method for the centrifugal compressor includes: S100, when an inlet opening of the centrifugal compressor is below a first preset value, shutting down a drive motor of the centrifugal compressor; or S200, when the inlet opening of the centrifugal compressor is not below the first preset value, performing the following operations in a preset order: decreasing the inlet opening of the centrifugal compressor, and increasing a rotate speed of the centrifugal compressor.

A heating, ventilation, and/or air conditioning (HVAC) system includes a compressor having an impeller configured to rotate and drive a working fluid through a working fluid circuit of the HVAC system in an active operating mode. The HVAC system further includes a controller configured to, in response to receiving an input indicative of a transition to operate in an inactive operating mode, suspend the active operating mode by interrupting a supply of power to the compressor, adjust pre-rotation vanes of the compressor, a variable geometry diffuser of the compressor to a first position, or both to enable a backflow of the working fluid through the compressor for a first interval of time, and, after the first interval of time has elapsed, adjust the pre-rotation vanes, the variable geometry diffuser, or both to a second position to block the backflow of the working fluid through the compressor.

A vacuum exhaust apparatus capable of accurately and rapidly adjusting the pressure in an exhaust chamber and a vacuum pump used therein are provided. A vacuum pump includes a rotor that rotates to exhaust an exhaust chamber and a casing having an inlet port. A valve is located between the inlet port of the vacuum pump and an outlet port of the exhaust chamber. A controller performs control such that the pressure in the exhaust chamber matches a target value. The controller adjusts the opening degree of the valve when the absolute value of the difference between the pressure in the exhaust chamber and the target value is greater than a predetermined value, and adjusts the rotational speed of the rotor of the vacuum pump when the absolute value of the difference between the pressure in the exhaust chamber and the target value is less than the predetermined value.