There is provided an integrated electric compressor that can be made small in size while reducing radio noise effectively. In an inverter of the electric compressor, a snubber circuit 21 comprising a resistor R and a capacitor C is provided between input/output terminals 20 of a power source and a switching element 18. The snubber circuit 21 is formed by surface mounting a resistive element constituting the resistor R and a capacitor element constituting the capacitor C on a power board 16. A leakage current from a motor 19 is thus restrained and radio noise is reduced. The resistive element and the capacitor element constituting the snubber circuit 21 are preferably surface mounted on the power board 16 on the side opposite to the side on which a control circuit board is arranged.

A pumping system for evacuating an enclosure comprises a pumping mechanism (30), a motor (32) for driving the pumping mechanism, and a controller (36) for controlling the motor. The controller sets a maximum value for a rotational frequency of the motor and a maximum value for a current in the motor, and, to optimise the performance of the pumping system, independently adjusts the maximum values during evacuation of the enclosure.

The present invention relates to a method for operating an undulating diaphragm pump comprising an undulating diaphragm and actuating means of the undulating diaphragm electrically powered according to a given frequency or voltage to make the undulating diaphragm oscillate and undulate. According to the invention, the method consists in modifying the electrical supply frequency and/or voltage of the actuating means according to at least one operating parameter, determined in advance, of the undulating diaphragm pump.

A method is provided for controlling a pump driven by a motor with the motor connected to a drive. The method can include determining a parameter value related to a fault condition, comparing the parameter value to a threshold value, and adjusting a speed control of the drive based on the comparison of the determined parameter to the threshold value.

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 compressor control device, a method for controlling a compressor, and a refrigerator including the same are provided. The compressor control device controls the compressor to be driven using a mode in which the compressor is selectively driven by an inverter and a mode in which the compressor is driven directly using a supply voltage, according to a quality of the supply voltage, a loss which is caused by use of the inverter reduced or removed by directly providing the supply voltage to the compressor within a predetermined voltage or frequency range, and an increased energy efficiency by reducing power consumption.

The disclosure provides a controller and server combination, which implements a set of software programs to control a booster pump system. In a preferred embodiment, the software derives quadratic models for the pump performance curves, and the system curve. The system monitors the flow rate of the system, the pump performance curve model and the system curve model to adjust the drive frequency and the number of active pumps to meet flow rate demand efficiency.

A system and method that controls the evacuation of fluid from a sea vessel and configured to prevent turning off the bilge pump during periods of water sloshing. The invention provides a control unit that is adaptable to any size vessel or bilge pump based on a learned experience gained by sensory information.

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 and method for a compressor includes a compressor connected to a condenser, a discharge line temperature sensor that outputs a discharge line temperature signal corresponding to a discharge line temperature of refrigerant leaving the compressor, and a control module connected to the discharge line temperature sensor. The control module determines a saturated condenser temperature, calculates a discharge superheat temperature based on the saturated condenser temperature and the discharge line temperature, and monitors a flood back condition of the compressor by comparing the discharge superheat temperature with a predetermined threshold. The control module increases a speed of the compressor when the discharge superheat temperature is less than or equal to the predetermined threshold.