A method and a device for controlling a capacity change of a compressor, and a smart home appliance. The method includes: determining whether a capacity of the compressor is required to be changed; if yes, determining an intermediate frequency; changing the capacity of the compressor while maintaining the operating frequency of the compressor at the intermediate frequency; and the maintaining the operating frequency of the compressor at the intermediate frequency reduces a sudden change in output of the compressor after the changing the capacity.

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.

A motor of an ESP is positioned in a wellbore. Measured data is received from one or more sensors. A first deep learning model miming on a motor controller of the ESP determines first operating parameters or first operating conditions for the ESP based on the measured data. The motor controller sends the first operating parameters or first operating conditions to a centralized computer system. A second deep learning model miming on the centralized computer system determines second operating parameters or second operating conditions associated with the ESP based on the first operating parameters or first operating conditions. The centralized computer system sends the second operating parameters or second operating conditions to the motor controller. The motor controller adjusts operation of the motor of the ESP based on the second operating parameters or second operating conditions.

A motor associated with an electric submersible pump (ESP) is positioned in a wellbore. Measurement data is received from one or more sensors. A deep learning model running on a motor controller associated with the ESP determines operating parameters or operating conditions of the ESP based on the measurement data. The motor controller adjusts operation of the motor of the ESP based on the determined operating parameters or operating conditions.

A high pressure threshold detection circuit (100) is provided. The high pressure threshold detection circuit includes a pressure transducer (110) for measuring a pressure of a medium at an outlet (104) of a compressor (102). The high pressure threshold detection circuit (100) includes a controller (120). The controller (120) includes a comparator (123) and a switch (125). The comparator (123) and the switch (125) are electrically coupled. The switch (125) is electrically coupled to an enable circuit (131). The pressure transducer (110) is electrically coupled to the comparator (123) to provide a signal to the comparator (123) based on the pressure measured at the outlet (104). The comparator (123) outputs a control signal (111) to the switch (125) when the signal (111) is equal to or greater than a reference value (126). The switch (125) opens the enable circuit (131) to disable compression of the medium by the compressor (102) in response to the control signal (111).

The disclosure discloses a method and a device for controlling cylinder switching of a compressor, a unit and an air conditioning system. The method includes: determining whether the compressor needs to perform cylinder switching; if so, adjusting current operating frequency according to a system pressure difference so that both the adjusted operating frequency and the system pressure difference meet a cylinder switching condition of the compressor; and controlling the compressor to perform cylinder switching. At the moment, the system pressure difference and the operation frequency are stable, and would not interfere the compressor's maintaining of the single-cylinder or double-cylinder operation state, which guarantees the energy efficiency of the unit where the compressor is located, and improves the use experience of a user.

A method for controlling a motor-driven pump in communication with a fluid system is provided. Preferably the method employs a frequency drive system to control the motor-driven pump. The control method is characterized in that the operating frequency of the motor can be adjusted very quickly and it is ensured to be operated in a safe frequency range no more than a rated current.

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.

An on-board fluid machine includes a housing configured to allow fluid to flow into the housing, an electric motor accommodated in the housing, and a driver that is supplied with DC power and drives the electric motor. The driver includes a low-pass filter circuit and an inverter circuit. The low-pass filter circuit includes a common mode choke coil and a capacitor. The driver further includes a damping unit located at a position where magnetic field lines produced by the common mode choke coil generate eddy current.

A high pressure threshold detection circuit (100) is provided. The high pressure threshold detection circuit includes a pressure transducer (110) for measuring a pressure of a medium at an outlet (104) of a compressor (102). The high pressure threshold detection circuit (100) includes a controller (120). The controller (120) includes a comparator (123) and a switch (125). The comparator (123) and the switch (125) are electrically coupled. The switch (125) is electrically coupled to an enable circuit (131). The pressure transducer (110) is electrically coupled to the comparator (123) to provide a signal to the comparator (123) based on the pressure measured at the outlet (104). The comparator (123) outputs a control signal (111) to the switch (125) when the signal (111) is equal to or greater than a reference value (126). The switch (125) opens the enable circuit (131) to disable compression of the medium by the compressor (102) in response to the control signal (111).