A heat pump apparatus includes: a compressor including a motor; an inverter that applies a desired voltage to the motor; a current detector that detects current flowing to the motor; a drive-signal generation unit that generates a drive signal for the inverter; a magnetic-pole position estimation unit that changes a voltage phase of a voltage command value for a high-frequency voltage, and estimates a maximum-heat-amount acquisition magnetic-pole position when the generation unit applies the high-frequency voltage to the motor to heat the compressor; a steady heating control unit that determines an amplitude and voltage phase of the voltage command value from the maximum-heat-amount acquisition magnetic-pole position and a defined necessary amount of heat when the generation unit applies the high-frequency voltage to the motor to heat the compressor; and a control switching determination unit that causes one of the estimation unit and the heating control unit to operate.

Included are: a compressor including a compression mechanism that compresses refrigerant, and a motor that drives the compression mechanism; an inverter that applies desired voltage to the motor; an inverter controller that controls the inverter; a high-pressure switch that operates when a discharge pressure of the compressor becomes a preset pressure or higher; and a thermal protector that operates when the temperature of the compressor becomes a preset temperature or higher, wherein the high-pressure switch and the thermal protector are installed on a power supply line for supplying power to the inverter, and the high-pressure switch is opened when the discharge pressure of the compressor becomes the preset pressure or higher, or the thermal protector is opened when the temperature of the compressor becomes the preset temperature or higher, to interrupt power supply to the inverter.

A direct-current power supply includes: a rectifier circuit in which switching elements are bridge-connected; a reactor; a gate circuitry that drives the switching elements; and a gate circuitry that drives the switching elements. A connection point between the switching element and the switching element is connected to an alternating-current power supply via the reactor, and a connection point between the switching element and the switching element is connected to the alternating-current power supply without via the reactor. A time during which the gate circuitry turns on the switching elements is longer than a time during which the gate circuitry turns on the switching elements.

A system includes a pressure exchanger (PX). The PX is coupled to a motor that controls an operating speed of the PX. The system further includes a first pressure gauge configured to generate first pressure data indicative of a pressure of a fluid of a condenser. A first controller is to generate a first control signal based on the first pressure data. The motor of the PX is configured to adjust the operating speed of the PX based on the first control signal. The system further includes a pump. The system further includes a fluid density sensor for generating fluid density data associated with a first output fluid of the PX. A second controller is to generate a second control signal based on at least the fluid density data. The pump is to adjust an operating speed of the pump based on the second control signal.

The present disclosure relates to a method for determining an efficiency curve of a chiller that includes operating a chiller over a range of operating capacities, measuring a temperature of water entering the chiller at an initial capacity, measuring a temperature of water exiting the chiller at the initial capacity, measuring a power consumption of the chiller at the initial capacity, calculating an initial efficiency of the chiller at the initial capacity, measuring a plurality of temperatures of water entering the chiller at a plurality of capacities, measuring a plurality of temperatures of water exiting the chiller at each of the plurality of capacities, measuring a plurality of power consumptions at each of the plurality of capacities, calculating a plurality of efficiencies at each of the plurality of capacities, and generating an efficiency curve for the chiller with the initial efficiency and the plurality of efficiencies.

An air-conditioning apparatus includes a four-way valve, a first three-way valve and a second three-way valve each having a closed port, a compressor, an indoor heat exchanger, an expansion valve, a first outdoor heat exchanger, a second outdoor heat exchanger, a bypass expansion valve, a check valve, a discharge temperature sensor, an indoor pipe temperature sensor, an indoor temperature sensor, a current sensor, and a controller configured to detect switching failure at the four-way valve, the first three-way valve, and the second three-way valve. The controller is configured to detect switching failure at the four-way valve, the first three-way valve, or the second three-way valve by using the temperatures measured by the discharge temperature sensor, the indoor pipe temperature sensor, and the indoor temperature sensor and the current in consideration of an operation status.

A chiller includes an evaporator, a compressor including a prime mover, a first pressure sensor that detects a first pressure in the evaporator, a second pressure sensor that detects a second pressure in a condenser, and a controller. The controller determines a predicted energy level of the compressor based on the first pressure and the second pressure, the predicted energy level associated with liquid droplet flow into the compressor, compares the predicted energy level to an operating energy level, and modifies the at least one of the input power and the input current to the prime mover based on the comparison satisfying a modification condition.

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 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.

Disclosed are a compressor control method, control apparatus and control system. The method includes: receiving a cylinder switching instruction, and detecting operating parameters of a compressor; determining whether a cylinder switching operation is completed according to the operating parameters of the compressor; and after it is determined that the cylinder switching operation is completed, performing torque compensation.