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 method and system for dynamic power allocation in a transport refrigeration system (TRS) is provided. The method includes a TRS power source operating in an operational state. The method also includes monitoring an amount of current being drawn from one or more generator powered components of the TRS. Also, the method includes calculating, via a TRS controller of the TRS, a maximum available horsepower amount based on the amount of current being drawn from the one or more generator powered components. Further, the method includes controlling, via the TRS controller, an amount of horsepower directed to a compressor of the TRS based on the maximum available horsepower amount.

In certain embodiments, a refrigeration system comprises an emergency electric power supply configured to supply power to at least one motor drive of the system. The system further comprises a power switch coupled to the emergency electric power supply, a tank configured to store a refrigerant, a first compressor configured to compress the refrigerant of the tank, and a controller coupled to the power switch and the first compressor. The controller may receive an indication from the power switch that the system is using the emergency electric power supply, and in response to receiving the indication from the power switch that the system is using the emergency electric power supply, operate the system in a first power outage mode. The controller may determine an amount of power to supply to the first compressor based on the first power outage mode and transmit a signal to instruct the first compressor to turn on.

A system includes an electronic power converter and a controller. The electronic power converter supplies power to one or more motor drives of an HVAC and/or refrigeration system. The controller obtains a plurality of pulse width modulation (PWM) algorithms. Each PWM algorithm has an associated harmonic signature. The controller further determines one or more resonance frequencies associated with the HVAC and/or refrigeration system. The controller also selects a first PWM algorithm from the plurality of PWM algorithms based at least in part on the harmonic signature associated with the first PWM algorithm mitigating the one or more resonance frequencies associated with the refrigeration system. The controller further operates the electronic power converter according to the first PWM algorithm.

A direct-current power supply device includes a switching unit constituted by a first switching element and a second switching element and a control unit that controls the operations of the first witching element and the second switching element. The switching unit has a first mode in which on-duty is a first value and a second mode in which the on-duty is a second value larger than the first value. When transitioning the switching unit from the first mode to the second mode, the control unit controls the switching unit such that the time until the on-duty reaches the second value is equal to or longer than a fixed time and controls, after the on-duty reaches the second value, an operation cycle of the switching unit to extend the operation cycle.

A cryogenic refrigeration system and method are disclosed. The cryogenic refrigeration system comprises: a refrigerator unit comprising an expansion unit and a variable speed compressor configured to compress refrigerant. The variable speed compressor is configured to receive refrigerant from the refrigerator unit via a lower pressure line and to supply compressed refrigerant to the refrigerator unit via a higher pressure line. There is also control circuitry configured to control the variable speed compressor to maintain a power consumption of the variable speed compressor below a predetermined threshold value, by during cooldown controlling the compressor to initially operate at a reduced frequency and later increasing a frequency of operation of the variable speed compressor such that the variable speed compressor operates at a higher frequency.

A system includes an alternating current (AC) to direct current (DC) voltage convertor, a power factor correction (PFC) subsystem, and one or more motor drives. The AC to DC voltage converter receives alternating current from an AC voltage source. The PFC subsystem receives DC voltage from the AC to DC voltage convertor. The PFC subsystem also outputs a corrected DC voltage corresponding to an output voltage setpoint. The PFC subsystem includes a controller operable to dynamically adjust the output voltage setpoint. The one or more motor drives receive voltage via the PFC subsystem. The output voltage setpoint is determined based at least in part on estimating a load associated with the one or more motor drives configured to receive voltage via the PFC subsystem.

A system includes a compressor driven by a motor. A condenser receives working fluid from the compressor. An evaporator is in fluid communication with the condenser and the compressor. A first sensor produces a first signal, and a second sensor produces a second signal. A processing circuitry processes the first signal and the second signal to determine a new baseline freeze time. The processing circuitry determines the new baseline freeze time for a predetermined time following an installation event, a service event, or a power outage of the compressor.

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.

System and method for monitoring and detecting potential problems early in a VCC based HVAC&R system employs a monitoring application or agent that uses continuous machine learning and a temperature map to derive or learn a relation between a measured input power parameter of one or more system compressors, and condenser and evaporator intake fluid temperatures, based on observations of the temperatures and the input power parameter when the HVAC&R system is new or in a newly maintained condition. The monitoring agent can then use the learned relation to determine, based on subsequent observations of the condenser and evaporator intake fluid temperatures, the input power parameter values that should be expected if the HVAC&R system were operating in the newly maintained condition. The agent can thereafter compare the expected compressor input power parameter values with observed input power parameter values to determine early whether the system is experiencing performance degradation.