An air conditioner includes a compressor having a compressor motor including coils, an indoor fan having a fan motor, a connection switching unit that switches a connection state of the coils between a first connection state and a second connection state in which a line voltage is lower than a line voltage in the first connection state, and a controller that controls the compressor motor, the fan motor, and the connection switching unit. The controller provides a stop period during which rotation of the compressor motor stops before the connection switching unit switches the connection state of the coils, and rotates the fan motor for at least a time period within the stop period.

An inverter module according to an embodiment of the present invention comprises: a high voltage circuit unit which generates an inverter control voltage and a motor driving voltage by using a first DC voltage; a high voltage circuit pattern which electrically connects the high voltage circuit unit; a low voltage circuit unit which communicates with an external device by using a second DC voltage having a smaller magnitude than the first DC voltage; and a low voltage circuit pattern which electrically connects the low voltage circuit unit. The high voltage circuit pattern and the low voltage circuit pattern are spaced apart from each other.

In a power converter, an inductance L of a reactor and a capacitance C of a capacitor satisfy a condition of the expression (1) below. In the power converter, a current-limiting circuit between an AC power source and the capacitor is unnecessary. Herein, αm ([A.Math.s]) is a value of a ratio of a maximum rated current squared time product to a maximum rated output current of diodes of a rectifier circuit, Pmax is a maximum power consumption of the motor, Vac is a voltage value of a three-phase AC voltage, and a value of a constant a is 4.3

[00001]$\begin{array}{cc}a.C.\sqrt{\frac{C}{L}}.Math.\frac{{\mathrm{Vac}}^3}{P_{\max }}\le {\alpha }_m.& \left(1\right)\end{array}$

A heat pump apparatus includes: a compression mechanism that compresses a refrigerant; a motor that drives the compression mechanism; an inverter that applies a voltage to the motor; and an inverter control unit that generates a drive signal for driving the inverter, based on a carrier signal, in which the inverter control unit periodically changes a carrier frequency of the carrier signal in a heating operation mode in which the refrigerant is heated, and generates the drive signal such that a period of time during which a voltage represented as a real vector is applied to the motor is kept constant regardless of the changed carrier frequency.

In order to restrain damage of a component due to rush current, a main relay in a power source circuit is not turned on and does not conduct a power source line even when a heat source microcomputer is activated with a capacitor not sufficiently charged. This configuration avoids start of charging the capacitor without current limitation, to restrain damage of the component due to rush current.

A motor drive device: a power conversion unit; a current detection unit that detects a phase current of the alternating-current motor; a position/speed specifying unit that specifies a magnetic pole position and a rotational speed of the alternating-current motor; a d-axis current pulsation generating unit that generates a d-axis current pulsation command based on q-axis current pulsation or a q-axis current pulsation command, which being in synchronization with the q-axis current pulsation or the q-axis current pulsation command and preventing or reducing an increase or decrease in amplitude of the voltage command; and a dq-axis current control unit that generates the voltage command for controlling the phase current on the dq rotating coordinates, which rotate in synchronization with the magnetic pole position, by using the magnetic pole position, the rotational speed, the phase current, the q-axis current pulsation or the q-axis current pulsation command, and the d-axis current pulsation command.

Provided is a refrigerant cycle apparatus capable of suppressing detects caused by iodine even when a refrigerant containing iodine is used. An air conditioner includes a refrigerant circuit through which a refrigerant containing iodine circulates. The refrigerant circuit includes a component that is in contact with a refrigerant containing iodine, the component being made of metal other than aluminum or an aluminum alloy, or having a content of aluminum which is equal to or less than a ratio at which corrosion of aluminum occurs by iodine. The component is at least one of a component of a compressor, a component of a heat-source-side heat exchanger or a utilization-side heat exchanger, a component of an expansion valve, a drier, and a connection pipe.

A cooling control device acquires temperatures detected by a plurality of temperature sensors installed at different positions in a target space. The cooling control device identifies a target position where a temperature sensor that has detected a temperature higher than a reference temperature is installed, among the plurality of temperature sensors, and controls an air volume of a blower so that an upper limit of reach of air cooled by a heat exchanger is within a target range defined about the target position as a reference.

The present disclosure relates to a motor operated compressor, including a housing, a compressor provided in the housing, a motor connected to the compressor to drive the compressor, an inverter coupled to one side of the housing, and connected to the motor unit in an electrically conductive manner. The motor operated compressor includes a hermetic terminal assembly, one side of which extends into the inverter unit, and an opposite side of which extends into the housing. A plurality of busbars have one end of each busbar connected to the opposite side of the hermetic terminal assembly, and the other end of each busbar connected to the motor unit. A first insulating cover portion encloses and seals the hermetic terminal assembly and the plurality of busbars inside the housing, such that a conductive body connecting the motor unit and the inverter unit in the main housing is sealed from refrigerant.

The present invention quickly stops rotation of an electric compressor while preventing damage to switching elements. An electric compressor 1 comprises a motor drive circuit 52 having multiple switching elements IGBT Q1 to Q6, a control unit 53 that controls driving of the multiple switching elements IGBT Q1 to Q6 and drives a motor 4, and a current detection unit 54 that detects a current flowing through the motor drive circuit 52. The control unit 53 performs stop control that stops rotation of the compression mechanism 3 by performing braking control that controls drive of predetermined switching elements IGBT (Q2, Q4, Q6 and the like) among the multiple switching elements IGBT Q1 to Q6. In the brake control, when the detected current value I is lower than the first threshold I.sub.1, the control unit 53 adjusts the drive pattern of the predetermined switching elements IGBT (Q2, Q4, Q6 and the like) in order to prevent the detected current value I from exceeding the second threshold I.sub.2 that is lower than the first threshold I.sub.1.