A compressor driving apparatus, or a home appliance including the same, includes a DC terminal capacitor to store a charge, an inverter to convert direct current associated with the charge of the DC terminal capacitor into an alternating current and output the alternating current to a motor, an output current detection unit to detect an output current flowing in the motor, and an inverter controller to increase a motor speed by starting the motor, and controlling a speed increase of the motor to change based on an increasing slope of a change in an output current detected by the output current detection unit during the speed increase of the motor.

An electric compressor includes a compression portion discharging a high pressure refrigerant by compressing a low-pressure drawn refrigerant, an electric motor driving the compression portion with a rotation of a rotor, a motor drive circuit driving the electric motor, an intermediate pressure port through which an intermediate pressure refrigerant is introduced into the compression portion, and a controller performing a rotation control of the rotor. When the controller stops the electric motor in a two-step compression mode in which the intermediate pressure refrigerant is introduced into the compression portion, the controller stops the rotor rotating by performing short-circuit braking on the electric motor and then fixes a rotational position of the rotor at a predetermined rotational position by performing direct current excitation on the electric motor.

An air conditioner comprising a blower unit to blow air at a predetermined amount, a cooling unit arranged downstream of the blower unit in an air flowing direction, a compressor which is operated at a variable operating frequency so that a revolving speed thereof is adjustable, a condenser, and a cooling coil connected in this order by pipes to circulate a heating medium to cool blown air. A heating unit is arranged on a downstream side of said cooling unit in the air flowing direction in which the blown air is heated by a heater. A control unit controls the operating frequency of the compressor and includes a compressor control part which adjusts the revolving speed of the compressor in such a way that the operating frequency of the compressor is decreased by a predetermined frequency when an output of the heating unit exceeds a first threshold value.

Controls for chillers with variable speed and variable geometry compressors are disclosed. In exemplary embodiments, a centrifugal compressor equipped with a variable frequency drive and variable inlet guide vanes may be utilized. A controller is operable to determine a chiller capacity command, a speed command, and a vane position command. The speed command and vane position command may maintain system operation at or near a surge control boundary over one or more capacity ranges to enhance efficiency and deviate from the surge control boundary over certain capacity ranges to improve controllability or avoid control aberrations.

A heat pump device includes a compressor including a motor, a heat exchanger, an inverter, and an inverter control unit. The inverter control unit generates a drive signal for the inverter. When the compressor is heated, the inverter control unit applies, to the motor, a high-frequency voltage with which the motor cannot be rotationally driven; estimates a magnetic pole position indicating a stop position of a rotor of the motor; determines an amplitude and a phase of a voltage command based on an estimation result of the magnetic pole position and a necessary amount of heat, and generates a drive signal.

There is provided a chiller control device (50) of a chiller system (1) that is provided with a centrifugal chiller (11) provided with a compressor (60) rotated by a motor (72), an operation panel (20) which is provided in the centrifugal chiller (11), operates the centrifugal chiller (11), and displays a state of the centrifugal chiller (11), and a starting panel (20) which supplies power to the motor (72) and starts the motor (72). The starting panel (10) begins supplying power to the motor (72) of the compressor (60) in response to a start command from the centrifugal chiller (11) to start the motor (72), and outputs a start answer and a start completion signal to the centrifugal chiller (11), and an abnormal state is output to the operation panel (20) if the start answer and/or the start completion signal continue to be output after the centrifugal chiller (11) has stopped.

A swimming pool heating system, including a heat pump and control of the compressor of the heat pump according to a number of non-zero power levels, is detailed. The system includes, for example, three power levels, the first level being close to 40% of the maximum compressor speed, the second level being close to 70% of the maximum compressor speed, and the third level being close to 100% of the maximum compressor speed.

A motor drive that enables the elimination of distortion of a motor current caused by direct current voltage ripples with the use of a smoothing capacitor having a small capacity and refrigeration equipment. A motor drive includes a rectifier circuit, a smoothing capacitor, voltage detector, an inverter circuit, current sensor, and a controller configured to control the inverter circuit. The controller has a voltage controller configured to generate a voltage command value used for controlling the motor, a ripple frequency arithmetic unit configured to operate a ripple frequency included in the direct current voltage signal, and a harmonic suppressor configured to process a signal based on the direct current signal using an S controller having a gain near the ripple frequency and output a corrected amount. The inverter circuit is controlled based on a signal that the voltage command value is corrected using the corrected amount.

A refrigeration system includes a variable capacity compressor system configured to pressurize refrigerant within a refrigerant circuit and a controller configured to receive data indicative of an operating capacity of the variable capacity compressor system and configured to adjust a superheat target setpoint of the refrigerant within the refrigerant circuit based on the data.

A liquefied gas cooling apparatus including: a gas flow path for carrying a liquefied gas that is liquefied by cooling; and a refrigeration unit including a refrigerating cycle formed by an evaporator for cooling the liquefied gas flowing through the gas flow path, a compressor, a condenser, and a throttle expansion unit. The compressor is driven through an electric motor contained in a sealed housing together with a compressor mechanism.