The purpose of the present invention is to provide a gas compressor that can achieve reduced fluctuation of discharge pressure during compressor body number control, and a method for controlling the gas compressor. 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 each of the inverters, in which discharge pipes of the compressor bodies are merged with one main discharge pipe and discharge pressure of the main discharge pipe is controlled through control of pressure of the respective discharge pipes by controlling, by means of the respective inverters, driving frequencies of the compressor bodies. The control device determines whether recovery through an increase in the driving frequency of the motor of each of the compressor bodies is possible, on the basis of the pressure value and a temporal changing amount of the discharge pressure of the main discharge pipe when the driving frequency of the motor of the compressor body is being increased but has not reached an upper limit frequency, and controls an increase of the number of the compressor bodies to be operated.

A linear actuator system includes a linear actuator and at least one proportional control valve and at least one pump connected to the linear actuator to provide fluid to operate the linear actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.

Systems and methods are disclosed of monitoring performance of an incompressible fluid system. The system has a positive displacement pump and a high bandwidth pressure sensor. A method comprises sensing a pressure of the fluid with the pressure sensor, determining pump ripple frequency and hence the speed of the positive displacement pump, calculating the pump flow rate, determining a flow restriction of the fluid system based on the pressure and flow, and assessing or trending the fluid system flow restriction.

A linear actuator system includes a linear actuator and at least one proportional control valve and at least one pump connected to the linear actuator to provide fluid to operate the linear actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.

A screw compressor system for a utility vehicle has at least one screw compressor, at least one screw compressor drive, at least one temperature probe and at least one control and regulation unit. The control and/or regulation unit is connected to the screw compressor drive and to the temperature probe and is designed and configured such that it controls, in accordance with a temperature threshold signal obtained from the temperature probe, the screw compressor drive with respect to a rotational speed.

A method of controlling the production efficiency of a well includes determining one or more parameters of a pump model for a pump of the well, determining an inflow rate of liquid into the well, and adjusting a pumping speed of the pump based on the one or more parameters of the pump model to maintain a outflow rate of liquid from the well at a desired fraction of the inflow rate.

A linear actuator system includes a linear actuator and at least one proportional control valve and at least one pump connected to the linear actuator to provide fluid to operate the linear actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.

A gas compressor includes a compression mechanism, a separator tank that introduces lubricating oil to be supplied to the compression mechanism and a mixed fluid of a working fluid and lubricating oil discharged from the compression mechanism and separates the lubricating oil. An oil cooler cools the lubricating oil from the separator tank. An oil circulation path supplies cooled lubricating oil to the compression mechanism. The gas compressor includes a suction temperature sensor that detects suction temperature of the working fluid, a discharge pressure sensor that detects discharge pressure of the compressed working fluid, a rotation speed sensor that detects rotation speed of the motor. A lubricating oil state estimation unit estimates the temperature of the lubricating oil based on the detected suction temperature, discharge pressure, and rotation speed of the motor. The lubricating oil state estimation unit uses this result to estimate the deterioration state of the lubricating oil.