A closed loop feedback control and diagnostics system for a transport climate control system is provided. The closed loop feedback control and diagnostics system includes a plurality of source current sensors configured to monitor current received from a high voltage three-phase AC power source. The closed loop feedback control and diagnostics system also includes a plurality of compressor current sensors configured to monitor current drawn by an electrically powered compressor of the transport climate control system. The closed loop feedback control and diagnostics system also includes a controller configured to receive source current signals from each of the plurality of source current sensors, configured to receive compressor current signals from each of the plurality of compressor current sensors, and configured to control operation of the transport climate control system based on the received source current signals and the received compressor current signals.

A drive circuit is provided and includes a rectification circuit, a buck converter, a first inverter, and a second inverter. The rectification circuit is configured to rectify a first AC voltage signal to generate a rectified voltage signal. The buck converter is configured to downconvert the rectified voltage signal to a DC voltage signal, wherein the DC voltage signal is supplied to a DC bus. The first inverter is configured to convert the DC voltage signal to a second AC voltage signal and supply the second AC voltage signal to a compressor motor. The second inverter is configured to convert the DC voltage signal to a third AC voltage signal and supply the third AC voltage signal to a condenser fan motor. Peak voltages of the second AC voltage signal and the third AC voltage signal are less than peak voltages of the first AC voltage signal.

A refrigeration system includes at least one compressor, a condenser, one or more sensors, and a controller. The one or more sensors are operable to sense data associated with the refrigeration system. The controller is operable to receive operating data associated a first control variable and a second control variable, the operating data received from the one or more sensors. The controller is further operable to determine, based on the operating data, that a control objective is not met, and operate the refrigeration system according to a configuration selected to cause the control objective to be met in response to determining that the control objective is not being met, wherein operating the refrigeration system according to the configuration selected to cause the control objective to be met comprises overriding control of the second control variable until the control objective is met.

An air conditioner includes an inverter circuit, a control unit that controls the inverter circuit, a compressor having a protection device (a pressure switch), and a phase-voltage detection circuit (a U-phase voltage detection circuit) that detects a voltage at any of three-phase windings (compressor windings) of the compressor. The control unit includes a shutdown-cause specifying unit that determines presence or absence of an operation of the protection device based on a phase voltage value detected by the phase-voltage detection circuit, by turning on any of a plurality of switching elements constituting the inverter circuit, after the compressor has been shut down, and specifies a cause of the shutdown of the compressor.

A motor drive control device includes a three-phase rectifier; a boosting circuit including a reactor, a switching element, and a backflow preventing element and boosts a direct-current bus voltage supplied from the three-phase rectifier; a smoothing capacitor; an inverter circuit; a boosting control unit; an inverter control unit; and a circuit protecting unit suppresses a ripple current flowing through the smoothing capacitor. In the circuit protecting unit, a correlation of an on-duty ratio of the switching element included in the boosting circuit, the output power of the inverter circuit, and an estimated ripple current are set. On the basis of the on-duty ratio of the switching element, output power of the inverter circuit, and the correlation, the circuit protecting unit determines an estimated ripple current flowing through the smoothing capacitor. When the estimated ripple current exceeds a preset threshold, the circuit protecting unit suppresses the ripple current.

A power converter including a compressor as a load includes a compensation current output (80) allowing compensation current (Ic), which compensates for leakage current (Ia), to flow. A controller (50) receives a detection signal from a rotational speed sensor (55) which senses the rotational speed of the compressor (CM). When the rotational speed has increased to a set rotational speed at which the leakage current (Ia) is lower than or equal to its limiting value (Lmax) (e.g., the limiting value specified under the Electrical Appliances and Materials Safety Act or by the IEC) in a state where the compensation current output (80) is off, the compensation current output (80) is switched from an on state to an off state. This may reduce the leakage current from the compressor with low power loss.

An air conditioner and a compressor protection circuit thereof are provided. When overcurrent occurs in a phase current of a compressor, an overcurrent level signal is output by a voltage comparison module, and is latched and output to an intelligent power module by a signal latching module, and the intelligent power module shuts off the output of the phase current according to the overcurrent level signal, so as to achieve the overcurrent protection of the compressor; and subsequently, a conventional level signal is output to the signal latching module by the voltage comparison module, the signal latching module keeps outputting the overcurrent level signal, and outputs the conventional level signal until a latching cancel signal output by a signal processing circuit is received, so that the intelligent power module starts the output of the phase current, thereby enabling the compressor to normally operate.

A refrigerator includes a motor to drive a compressor, an output current detector to detect an output current flowing to the motor, a compressor controller to calculate a power consumed in the compressor based on the detected output current, a plurality of power consuming units, and a main controller to receive the calculated compressor power consumption information, and when the plurality of power consuming units operate, to calculate a final power consumption using power consumption information stored for each power consuming unit and the calculated compressor power consumption information. Accordingly, computation of a power consumption may be simply performed.

A climate-control system may include a compressor, a condenser, an evaporator, a first sensor, a second sensor, a third sensor, and a control module. The compressor may include a motor and a compression mechanism. The condenser receives compressed working fluid from the compressor. The evaporator is in fluid communication with the compressor and disposed downstream of the condenser and upstream of the compressor. The first sensor may detect an electrical operating parameter of the motor. The second sensor may detect a discharge temperature of working fluid discharged by the compression mechanism. The third sensor may detect a suction temperature of working fluid between the evaporator and the compression mechanism. The control module is in communication with the first, second and third sensors and may determine whether a refrigerant floodback condition is occurring in the compressor based on data received from the first, second and third sensors.

A system includes a plurality of compressors, an evaporator, an expansion device, and a system controller. The compressors may be linked in parallel. The system controller may: determine a saturated evaporator temperature, a saturated condensing temperature, and a target capacity demand; determine an estimated system capacity and an estimated power consumption for each compressor operating configuration; compare the estimated system capacity with the target capacity demand and an error tolerance value; select an optimum operating mode based on the comparisons and based on the estimated power consumption; and command activation and deactivation of the plurality of compressors to achieve the selected optimum operating mode. The optimum operating mode may be selected after the normal system logic achieves a steady state and may be selected from a group having the estimated system capacity within the error tolerance of the target capacity demand and a lowest associated power consumption value.