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.

Techniques facilitating mechanical vibration management for cryogenic environments are provided. In one example, a system can comprise a processor that executes computer executable components stored in memory. The computer executable components can comprise a linearization component and a drive component. The linearization component can translate data indicative of a nonlinear drive signal into a linear drive signal. The drive component can dynamically control operation of a compressor of a cryocooler using the linear drive signal. The cryocooler can provide cooling capacity for a cryogenic environment.

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 method controls a refrigerator. The refrigerator includes a compressor using that includes a piston and uses refrigerant as lubricant for the piston, and the method includes determining an end time point of a refrigerant recovery operation based on a driving input value of the compressor to thereby reduce abrasion of the piston and power consumption.

[Object] On the basis of a limit of an operation of a control unit that is connected to a power-receiving path of a converting unit, is electrically parallel with the converting unit, and controls apparent power in the power-receiving path of the converting unit, the operation of the control unit is controlled.

[Solution] A power control system includes: an acquisition section that acquires control unit information related to a limit of an operation by a control unit provided for a heat pump system that regulates temperature and/or humidity; and a control section that controls an operation of the control unit on the basis of the control unit information. The control unit is connected to a power-receiving path of a converting unit that converts received power and supplies the converted power to a load used for the regulating. The control unit is electrically parallel with the converting unit. The control unit controls apparent power in the power-receiving path.

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.

A motor driving device that drives a motor and is capable of switching a connection state of stator windings of the motor, includes: relays to switch the connection state of the stator windings by switching positions of contact plates; and a contact control unit to control each of the positions of the contact plates by outputting, to the relays, signals for actuating the contact plates. The contact control unit switches the connection state by sequentially switching output values of the signals such that the output values of the signals are switched at different timings from each other in the relays, and changes a switching order every time the connection state is switched, the switching order being an order in which the output values of the signals are switched.

A drive circuit includes a rectification circuit, a buck converter, and an 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 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 and to a condenser fan motor. The peak voltages of the second AC voltage signal are less than peak voltages of the first AC voltage signal.

The invention relates to an electric compressor control device comprising a low-voltage domain. The low-voltage domain comprises a first control unit set up to process control commands for the control of the electric compressor, and a first voltage supply set up to supply the first control unit and connected to a low-voltage source. The low-voltage domain comprises furthermore a high-voltage domain. The high-voltage domain comprises a second control unit set up to control a power output stage, wherein the power output state inverts a dc voltage from a high-voltage source into an ac voltage in order to supply a motor of the electric compressor with the ac voltage. The high-voltage domain comprises furthermore a second voltage supply set up to supply the second control unit and connected to the high-voltage source.

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.