A compressor arrangement for operating a compressed air supply facility of a vehicle includes a compressor having an electric motor constructed as an electronically commutated, brushless DC motor with a control circuit comprising a power electronics unit, and a pneumatic compressor. The electric motor is constructed in the form of an external rotor motor.

A control system and method of a VFD-based pump. The control system controls an electric motor via a VFD, and the electric motor drives the pump. The control system comprises: an anti-ripple injection module for injecting an anti-ripple signal into a control path, the anti-ripple signal causing pressure ripples in the pump output to be at least partially cancelled. Further a pump system, comprising: a VFD, an electric motor, and a pump, wherein the VFD comprises the control system stated above.

A variable frequency drive system and a method of controlling a pump driven by a motor with the pump in fluid communication with a fluid system is provided. The method includes monitoring a pressure in the fluid system, monitoring and adjusting an operating frequency of the motor to maintain the pressure at a pressure set point, and, based on the monitored operating frequency, causing the pump to temporarily boost the pressure in the fluid system to a temporary boost set point for a first time period. The method also includes determining whether the temporarily boosted pressure in the fluid system stays above the pressure set point for a second time period and causing the pump to enter a sleep mode when the temporarily boosted pressure stays above the pressure set point through the second time period.

A variable frequency drive system and a method of controlling a pump driven by a motor with the pump in fluid communication with a fluid system is provided. The method includes monitoring a pressure in the fluid system, monitoring and adjusting an operating frequency of the motor to maintain the pressure at a pressure set point, and, based on the monitored operating frequency, causing the pump to temporarily boost the pressure in the fluid system to a temporary boost set point for a first time period. The method also includes determining whether the temporarily boosted pressure in the fluid system stays above the pressure set point for a second time period and causing the pump to enter a sleep mode when the temporarily boosted pressure stays above the pressure set point through the second time period.

The present invention provides a method and system for providing on-site electrical power to a fracturing operation, and an electrically powered fracturing system. Natural gas can be used to drive a turbine generator in the production of electrical power. A scalable, electrically powered fracturing fleet is provided to pump fluids for the fracturing operation, obviating the need for a constant supply of diesel fuel to the site and reducing the site footprint and infrastructure required for the fracturing operation, when compared with conventional systems.

A system, method, and computer-readable medium for determining the flow rate and fluid density in an electrical submersible pump (ESP) and controlling the ESP based on the flow rate and density. In one implementation, an ESP system includes an ESP, drive circuitry, a current sensor, a voltage sensor, and a processor. The ESP includes an electric motor. The drive circuitry is electrically coupled to the ESP and is configured to provide an electrical signal to power the ESP. The current sensor is configured to measure a current of the electrical signal. The voltage sensor is configured to measure a voltage of the electrical signal. The processor is configured to calculate speed of a shaft of the electric motor based on a frequency induced by rotation of the motor detected in the current. The processor is also configured to calculate a density of fluid in the ESP based on the speed.

A system for operational acoustic optimization of a variable speed compressor (2) includes a motor (6), a frequency inverter (3), and a control block (5). The frequency inverter (3) is electrically connected to the synchronous motor (6), an electrical network (4), and the control block (5). The control block (5) is configured to control the speed of the motor (6) and to establish a first switching frequency (F1) and a second switching frequency (F2) of the frequency inverter (3). The frequency inverter (3) is configured to start the variable speed compressor (2) by supplying motor (6) with a signal (9) with the first switching frequency (F1) for the duration of a time period (T1) corresponding to at least one alignment operation period of the motor (6) and to supply the motor (6) with a signal (9) with the second switching frequency (F2) after the time period (T1).

The present invention provides a method and system for providing on-site electrical power to a fracturing operation, and an electrically powered fracturing system. Natural gas can be used to drive a turbine generator in the production of electrical power. A scalable, electrically powered fracturing fleet is provided to pump fluids for the fracturing operation, obviating the need for a constant supply of diesel fuel to the site and reducing the site footprint and infrastructure required for the fracturing operation, when compared with conventional systems.

An operating method is used for a compressor of a refrigerating machine, where the compressor includes an electric motor- and a power supply device configured to modulate a supply voltage and/or current and/or frequency for driving an electric motor. The method includes (a) setting a stator resistance calibration value and at least one threshold value for a control parameter, the threshold value being correlated to the calibration value; (b) injecting, continuously during operation of the electric motor, a disturbance signal into the electric motor (c) detecting a resulting voltage signal and a resulting current signal, corresponding to the perturbation signal; (d) associating with the control parameter a value calculated as a function of the resulting voltage signal and a resulting current signal; and (e) regulating or interrupting the supply voltage and/or current and/or frequency depending on the control parameter with respect to the at least one threshold value.

A system, method, and computer-readable medium for determining the flow rate and fluid density in an electrical submersible pump (ESP) and controlling the ESP based on the flow rate and density. In one implementation, an ESP system includes an ESP, drive circuitry, a current sensor, a voltage sensor, and a processor. The ESP includes an electric motor. The drive circuitry is electrically coupled to the ESP and is configured to provide an electrical signal to power the ESP. The current sensor is configured to measure a current of the electrical signal. The voltage sensor is configured to measure a voltage of the electrical signal. The processor is configured to calculate speed of a shaft of the electric motor based on a frequency induced by rotation of the motor detected in the current. The processor is also configured to calculate a density of fluid in the ESP based on the speed.