A heat pump device includes an inverter control unit for controlling an inverter. The inverter control unit includes a constraint-energization control unit that, during operation standby of a compressor, determines whether heating to the compressor is necessary, on the basis of a refrigeration stagnation amount in the compressor, and, when having determined that heating to the compressor is necessary, selects, according to the refrigeration stagnation amount, any one of direct-current energization for supplying a direct-current voltage to the motor and high-frequency energization for supplying a high-frequency voltage having a frequency higher than a frequency during a normal operation to the motor, so as to output a constraint energization command for carrying out constraint energization of the motor; and a driving-signal generating unit that generates a driving signal on the basis of the constraint energization command.

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 rotor includes a cylindrical a rotor core having a plurality of magnet insertion holes extending along a central axis of the cylindrical shape and permanent magnets inserted into the magnet insertion holes, respectively. A slit extending along the central axis is provided between an outer circumferential surface of the rotor core and at least one of the magnet insertion holes. The slit inner lines extend toward the outer circumferential surface of the rotor core from the apex of the slit, the apex being located on a side of the magnet insertion holes. The slit outer line connects side ends of the slit inner lines located on a side opposite to the apex.

Provided is an air conditioner including at least one indoor unit; an EHP outdoor unit connected with the at least one indoor unit, and configured to control an applied current and drive an EHP compressor; a GHP outdoor unit connected with the at least one indoor unit and including a GHP compressor configured to operate using power from an engine driven through a combustion gas and an oil separator provided at an outlet side of the GHP compressor; an oil level sensor provided at the EHP outdoor unit or the GHP outdoor unit and configured to detect an amount of oil; and a control part configured to control an RPM of the EHP compressor or the GHP compressor based on information detected by the oil level sensor.

A method and an apparatus for adjusting an operating frequency of an inverter compressor are provided. The method includes following steps: detecting whether an inverter air conditioner is in a heating mode; obtaining a target operating current of the inverter compressor if the inverter air conditioner is in the heating mode; adjusting the operating frequency of the inverter compressor according to the target operating current; obtaining an operating parameter of the inverter compressor and obtaining a maximum operating frequency of the inverter compressor according to the operating parameter; obtaining a current correction according to the maximum operating frequency and correcting the target operating current according to the current correction to update the target operating current.

A system includes a variable-capacity compressor operable in a first capacity mode and in a second capacity mode that is higher than the first capacity mode. A control module is configured to switch the variable-capacity compressor between the first capacity mode and the second capacity mode based on a demand signal from the thermostat. The control module determines a number of previous consecutive operating cycles of the variable-capacity compressor in the first capacity mode within a predetermined period of time. The control module operates the variable-capacity compressor in the second capacity mode in response to the number of previous consecutive operating cycles of the variable-capacity in the first capacity mode within the predetermined period of time exceeding a predetermined threshold.

The present invention is provided with an extraction device (40) including: a cooling unit for cooling gas that has been extracted from a condenser (5) and condensing condensed gas; and an exhaust pump (48) for discharging, to the exterior, uncondensed gas that has been isolated without having been condensed by the cooling unit. A current temperature difference, which is the difference between the current saturation temperature in the condenser (5) and the current outlet temperature of a cooling water heat transfer tube (5a), and a planned temperature difference, which is a planned value, are computed. Using information on an in-tube fouling temperature difference elevation, which is a difference between the saturation temperature in the condenser (5) and the outlet temperature of the cooling water heat transfer tube (5a) and which is predetermined assuming in-tube fouling of the cooling water heat transfer tube (5a), the temperature difference elevation due to the current in-tube fouling is computed. The extraction device (40) is operated if the elevation of the current temperature difference from the planned temperature difference is greater by a predetermined value or more than the temperature difference elevation due to the current in-tube fouling.

A heat pump and a control method thereof, the control method of the heat pump which heats a heated space through heat exchange between outdoor air and a refrigerant and heat exchange between the refrigerant and circulation water, includes calculating the maximum allowable frequency of a compressor based on the temperature of the outdoor air and the heating load of the heated space, calculating the mean operating frequency of the compressor while the compressor is operated at the calculated maximum allowable frequency, recalculating the maximum allowable frequency based on a result of comparison between the mean operating frequency and the maximum allowable frequency, and operating the compressor at the recalculated maximum allowable frequency, thereby improving coefficient of performance (COP) of the heat pump.

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.

The present invention has an object to suppress an overshoot in the outlet temperature of a heat medium. A heat source machine controlling apparatus includes a computing unit and a set temperature changing unit. The computing unit calculates a load change rate using a predetermined arithmetic expression. The set temperature changing unit determines whether or not the load change rate calculated by the computing unit exceeds a predetermined threshold value. In the case where the load change rate exceeds the predetermined threshold value, the set temperature changing unit changes a set chilled water outlet temperature so as to suppress a change in a chilled water outlet temperature. For example, in the case where the chilled water outlet temperature is on a falling trend, if the set chilled water outlet temperature is set to a relatively high value, the heat source machine load decreases, and the chilled water outlet temperature is controlled to coincide with the set chilled water outlet temperature after the change. Consequently, an overshoot can be suppressed.