A heat pump device includes an inverter control unit outputting PWM signals to an inverter; a current detection unit detecting a current value flowing in the inverter and outputting the current value after reducing a current value having a first frequency or higher in detected current value; and a drive-signal stop unit that, when the current value output from the current detection unit is equal to or larger than an interruption level, stops output of PWM signals to the inverter. Particularly, the inverter control unit generates a voltage command value such that the voltage command value becomes a value equal to or larger than a lower limit determined according to the first frequency and generates PWM signals based on generated voltage command value and a carrier signal, thereby causing a voltage output time to the motor to be a predetermined time or longer.

A vehicle, a refrigerator for a vehicle, and a method for controlling a refrigerator for a vehicle are provided. The method for controlling the refrigerator for the vehicle includes turning on a switch of the refrigerator for the vehicle, measuring a temperature of an interior of the refrigerator for the vehicle a first time, measuring a temperature of the interior of the refrigerator for the vehicle again a second time after a predetermined time has elapsed from the first time, determining a temperature change of the interior of the refrigerator from the first time to the second time, and operating the refrigerator for the vehicle in a quench mode in which the temperature in the interior of the refrigerator is rapidly lowered, unlike a normal mode, if the temperature change in the interior of the refrigerator is in a positive direction.

A preheater for a compressor that is capable of heating a lubricant oil efficiently with smaller power is provided. A preheater for a compressor includes: a capacitive oil surface sensor that is provided at a compressor used in a refrigerating cycle, and detects an oil surface of a lubricant oil A in the compressor; and a power supply unit that applies high-frequency voltage to the oil surface sensor.

A heat exchanger incorporates a metal hydride heat exchanger and mitigates the fluid mixing process, and thus greatly improves the heat transfer efficiency and heat recovery processes. The metal hydride heat exchanger has a container for the metal hydride that has a large aspect ratio. A plurality of high aspect container for the metal hydride may be coupled with a manifold.

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.

The invention relates to a method of operating at least one distributed energy resource comprising a refrigeration system (1) with a number of cooling entities, wherein a power consumption information is communicated to a smart-grid setup (SG). According to the invention the method comprises the steps of: requesting (S0) a power consumption information from the refrigeration system; transmitting (S1) the power consumption information from the refrigeration system (1), wherein a total amount of power consumption (Pmin, Pmax) of the refrigeration system (1) is provided; wherein: a cooling capacity (dQ/dt_i) of at least one cooling entity is determined wherein an entity operation condition (CE) of the cooling entity (E1, E2) is taken into account (D1); a power consumption (W_i) of at least one cooling entity (E1, E2) is determined from the cooling capacity (dQ/dt_i) wherein a performance estimation (COP) of a refrigeration cycle for the cooling entity (E1, E2) is taken into account (D2); providing (D3) the total amount of power consumption (Pmin, Pmax) as a sum of power consumptions (W_i) of at least the one cooling entity of the number of cooling entities (E1, E2), in particular as a sum of relevant power consumptions of the number of cooling entities (E1, E2); receiving (S2) at the refrigeration system (1) a power reference (Wref) from the smart-grid setup (SG). The method presented enables power control of a centralized refrigeration system in a smart-grid setup where an aggregator provides the power reference. In addition, the method also enables the refrigeration system to improve determining flexibility margins beyond absolute max./min values of nominal and zero.

A heat pump device includes a compressor compressing refrigerant; a motor driving the compressor; an inverter applying alternating-current voltage to the motor; and an inverter control unit generating a control signal for controlling the inverter. The inverter control unit executes control by using a first switching pattern in which all of three switching elements on a positive or negative voltage side of the inverter are changed to an ON state, then executes control by using a second switching pattern in which two switching elements to which electric current flows in the same direction when controlled by using the first switching pattern are changed to an OFF state, and then executes control by using a third switching pattern in which two switching elements on a reverse voltage side of the two switching elements changed to an OFF state by using the second switching pattern are changed to an ON state.

A control method and system for a resonant linear compressor applied for controlling the capacity of a cooling system. The method includes: a) reading a reference operation power (P.sub.ref) of the motor of the compressor; b) measuring an operation current (i.sub.MED); c) measuring an operation voltage of a control module of the compressor; d) calculating an input power (P.sub.MED) of the motor as a function of the operation current (i.sub.MED) and of the operation voltage; e) comparing the input power (P.sub.MED) with the reference operation power (P.sub.ref); f) if the reference operation power (P.sub.ref) is higher than the input power (P.sub.MED), then increase an operation voltage of the compressor (UC); g) if the reference operation power (P.sub.ref) is lower than the input power (P.sub.MED), then decrease the operation voltage of the compressor (UC).

A method of feedthrough and overcurrent protection of a sealed compressor used in a transport climate control system (“TCCS”) is provided. The TCCS includes a climate control circuit with a sealed compressor. The sealed compressor includes an outer housing and an electrical motor within the outer housing. The method includes operating the sealed compressor to compress a working fluid by supplying electrical power to the electric motor of the sealed compressor via a sealed electrical feedthrough in the outer housing of the sealed compressor. The method also includes detecting an operating parameter of the sealed electrical feedthrough, and determining whether the sealed electrical feedthrough is in a melting condition based on the detected operating parameter. Also, the method includes adjusting operation of the climate control circuit upon determining that the sealed electrical feedthrough is in the melting condition until the sealed electrical feedthrough is no longer in the melting condition.