Low-flow fluid delivery system. The system includes a pump assembly comprising a pump mechanism having an inlet side and an outlet side, wherein the inlet side is configured to fluidly couple to a fluid supply. The system further includes a pressure sensor operably coupled to the outlet side and configured to measure a fluid pressure at the outlet side. An actuator mechanically is coupled to the pump mechanism to drive the pump mechanism. A controller is coupled to the pressure sensor, wherein the controller is configured with a preselected set of fluid pressure set points and one or more preselected sets of fluid flow rates and wherein the controller is further configured to control the actuator to increase a fluid flow rate to a first flow rate in the preselected set of fluid flow rates when the fluid pressure at the outlet side falls to a lower one of corresponding fluid pressure set point in the preselected set of fluid pressure set points. The controller is further configured to control the actuator to reduce the fluid flow rate to a second fluid flow rate in the preselected set of fluid flow rates, when the fluid pressure at the outlet side rises to an upper one of a corresponding fluid pressure set point in the preselected set of fluid pressure set points.

An electric submersible pump (ESP), comprising: an intake that suctions fluids into the ESP, wherein the fluids include a mixture of gas, water, and oil; a discharge that discharges the fluids from the ESP; an acoustic intake transducer that determines the speed of sound in the fluids suctioned into the ESP at the intake; and a first acoustic discharge transducer that determines the speed of sound in the fluids discharged from the ESP, wherein the speed of sound of the fluid at both intake and discharge is used to calculate a gas volume fraction difference of the multiphase fluid mixture across the intake and discharge of the pump, and wherein the gas volume fraction difference is used as feedback to control the ESP.

A motor-driven compressor for a vehicle includes a control device and a detection circuit. The detection circuit includes an AD conversion circuit. The AD conversion circuit converts an on-voltage from an analog signal to a digital signal. The control device is configured to determine that a battery is in an overvoltage state and stop the motor-driven compressor for the vehicle when a value of the on-voltage detected from the digital signal is larger than an overvoltage determination threshold value.

A method for determining operating properties of a drill-rod borehole pump, having a pump head, which is connected to a kinematics converter via a drill rod, and the kinematics converter is driven by an electric motor, and furthermore a measuring device is provided for measuring the power consumption of the motor during operation of same.

A control method for a compressor system includes a compressor connected to a pressure vessel and a frequency converter controlling an electric motor of the compressor. In the method, the present operating state is estimated on the basis of a monitored/estimated electrical quantity of the compressor system. The operating state may represent the pressure in the pressure vessel. The pressure in the pressure vessel causes a counter-torque to the motor. The counter-torque is proportional to the pressure and may be used for estimating the pressure inside the pressure vessel. An estimate of a counter-torque may be calculated on the basis of the monitored electrical quantity or quantities.

A sensor module for a compressor having an electric motor connected to a power supply is provided. The sensor module includes: a first input connected to a first voltage sensor that generates a voltage signal corresponding to a voltage of the power supply; a second input connected to a first current sensor that generates a current signal corresponding to a current of the power supply; and a processor connected to the first and second inputs. The processor monitors the first and second inputs and, based on voltage measurements from the first input and current measurements from the second input, detects at least one of: (i) an unexpected variation of electric power from the power supply; and (ii) a mechanical malfunction. The processor is disposed within an electrical enclosure of the compressor, the electrical enclosure being configured to house electrical terminals for connecting the power supply to the electric motor.

A hybrid work machine that can suppress excessive limiting on pump absorption power even in a situation in which supply of electric power to an electric motor is limited is provided. The hybrid work machine includes: an engine 22; an assist generator motor 23 connected to the engine 22 in such a manner that a torque can be transmitted to the engine 22; an electric storage device 24 that supplies electric power to the assist generator motor 23; a monitoring device 28 that monitors the electric storage device 24 and that acquires electric storage device information; a hydraulic pump 41 driven by the engine 22 and the assist generator motor 23; and a pump regulator 43 that regulates a delivery flow rate of the hydraulic pump 41. The hybrid work machine includes: an increasing rate computing section 81 that computes an allowable increasing rate r in response to the electric storage device information for pump absorption power; a limited power computing section 82 that computes a limited value WPlim of the pump absorption power on the basis of the allowable increasing rate r; and a pump control section 86 that controls the delivery flow rate of the hydraulic pump 41 in response to the limited pump power WPlim.

The present disclosure describes a load/unload control method for a compressor system with a rotating compressor connected to a pressure vessel. In the method, the present operating state can be monitored on the basis of a monitored/estimated electrical quantity of the compressor system. The method comprises an identification phase and an operational phase. In the identification phase, the compressor is operated at a constant rotational speed to generate two known pressures to the pressure vessel. At least one electrical quantity is monitored, and values of the electrical quantity corresponding to the pressure limits are stored. In the operational phase, reaching of a pressure limit may then be detected by comparing the present value of the monitored electrical quantity to the stored values.

A startup control method for a fuel cell is provided. The method includes calculating available power of a high-voltage battery when a startup of the fuel cell is requested. An air compressor is then driven based on a calculated magnitude of the available power of the high-voltage battery and a low-voltage battery is charged with the power of the high-voltage battery after the driving of the air compressor is completed.

A pumping system for at least one aquatic application includes a motor coupled to a pump and a controller in communication with the motor. The controller is adapted to determine a first motor speed of the motor, determine a reference power consumption using a reference flow rate and a curve of speed versus power consumption for the reference flow rate, and generate a difference value between the reference power consumption and a present power consumption. The controller drives the motor to reach a steady state condition at a second motor speed based on the difference value.