The invention provides an air conditioner control method and device and an air conditioner. The air conditioner control device acquires a current temperature of a chilled water of a unit at a preset period; determine a target load of the unit, a target temperature of a chilled water and a target temperature of a cooling water based on a temperature of the chilled water set by a user and the current temperature of the chilled water; determine an evaporating parameter and a condensing parameter of the unit based on the target load of the unit, the target temperature of the chilled water and the target temperature of the cooling water; and determine operation parameters of a compressor based on the target load of the unit, the evaporation parameter and the condensation parameter. Therefore, the unit can operate based on the operation parameters.

A heat pump apparatus includes: a refrigerant circuit which circulates refrigerant; a heat medium circuit which makes a heat medium flow; a heat exchanger which cause heat exchange to be performed between the refrigerant and the heat medium; and an indoor unit which houses at least the heat exchanger. The heat exchanger has a double-wall structure. The indoor unit includes a container which houses the heat exchanger. In the container, a first opening port is formed to communicate with an outdoor space without communicating with an indoor space.

A compressor driving device includes a three-phase alternating current power supply input end, a relay module, a rectifier circuit, and a driving control circuit which are sequentially connected; the rectifier circuit is used for converting connected alternating current into direct current and then outputting the direct current to a direct current bus; the driving control circuit is used for converting the direct current output by the direct current bus into compressor driving power; a pressure switch is used for measuring the pressure value in a refrigerating system, and when the measured pressure value is larger than a preset pressure threshold, disconnecting the power supply circuit of the relay module; the driving control circuit is also used for detecting the on-off state of the pressure switch and controlling the compressor to stop working when the pressure switch is switched off.

A device management system for an inverter compressor is a device management system for an inverter compressor provided with a motor to be driven by an inverter, and includes: a partial discharge detector that detects a voltage of the motor to detect a partial discharge that occurs in the motor; and a determination module that determines whether there is a risk of occurrence of the partial discharge or whether the partial discharge occurs based on a result of detection by the partial discharge detector. When the voltage detected by the partial discharge detector is higher than a first threshold, the determination module determines that there is a risk of the occurrence of the partial discharge or the partial discharge occurs, and performs a protective operation to reduce the risk of the occurrence of the partial discharge in the motor or the occurrence of the partial discharge in the motor.

Provided is an air conditioner compressor operating power detecting method comprises: detecting a compressor driving power supply frequency as the air conditioner running; calculating a drive power supply period T based on the detected drive power supply frequency f wherein the drive power supply period T=1/f; the driving power supply period T is equally divided into n time segments; and in each time segment, respectively sampling a compressor drive voltage, respectively sampling a compressor drive current in each time segment; calculating a voltage reference value U′; calculating a current reference value I′; obtaining a plurality of voltage reference values U′; obtaining a plurality of current reference values I′; calculating a mean voltage reference value U.sub.mean, calculating a mean current reference value I.sub.mean, calculating a compressor operating power P.sub.compressor. Another aspect is provided an air conditioner. The invention has advantages of being accurate in calculation.

A method for controlling a refrigerator includes turning on a compressor to operate with a predetermined cooling power for cooling a storage compartment, turning off the compressor when a temperature of the storage compartment reaches a temperature equal to or lower than a first reference temperature, and turning on the compressor again when the temperature of the storage compartment reaches a temperature equal to or higher than a second reference temperature higher than the first reference temperature. In the turning on the compressor again, the compressor is operated with a cooling power determined based on an on slope, which is a temperature change slope of the storage compartment during an on time of the compressor, and an off slope, which is a temperature change slope of the storage compartment during an off time of the compressor.

A refrigerant leakage determination system capable of detecting leakage of refrigerant without requiring complicated processing is provided. A refrigerant leakage determination system is a refrigerant leakage determination system of a refrigeration cycle apparatus that includes a refrigerant circuit including a heat-source-side heat exchanger and has, as operating modes, a normal mode in which the heat-source-side heat exchanger is caused to function as an evaporator and a defrosting mode in which the heat-source-side heat exchanger frosted during a normal operation is defrosted. The refrigerant leakage determination system includes a processor configured to acquire defrosting information regarding a relationship between a normal operation period and the number of defrosting operations, and memory that stores the defrosting information. The processor is further configured to determine, based on the acquired defrosting information, leakage of refrigerant in the refrigerant circuit.

Systems and methods for monitoring an HVAC&R system employ a monitoring agent that uses observations of evaporator and condenser intake temperatures, evaporator discharge temperature, and a compressor input power parameter to learn operating characteristics of the HVAC&R system in newly maintained condition. Thereafter, the agent continuously or regularly computes a relative coefficient of performance (COP) for the system under subsequent observed ambient conditions, and relates the present instantaneous efficiency of the HVAC&R system under the observed ambient conditions to the instantaneous efficiency when the system was in newly maintained condition. The relative COP can be used to detect system degradation and quantify the energy usage and cost attributable to the degradation. The agent can take appropriate actions to prevent/minimize damage based on the degree of degradation detected, including shutting off power to the HVAC&R system. The monitoring agent can also be extended to other types of systems besides HVAC&R system.

A rotary-machine control device includes: a connection switching device switching a connection state of stator windings of a rotary machine; a current detection unit detecting a rotary machine current flowing in the rotary machine; a voltage application unit applying voltage to the rotary machine; a control unit generating a voltage command provided to the voltage application unit and outputting a switching command to switch the connection state to the connection switching device; and an open-phase determination unit determining presence or absence of disconnection in the rotary machine or presence or absence of disconnection of a power distribution line to the rotary machine. During rotation of the rotary machine, the control unit outputs the switching command and the open-phase determination unit determines presence or absence of disconnection.

A method for operating an appliance motor includes receiving a target speed for the motor, obtaining a power limit for the motor, determining an inverter current limit based at least in part on the target speed and the power limit, determining an inverter output current to achieve the target speed, wherein the inverter output current is limited to the inverter current limit, and supplying the motor with the inverter output current.