Abstract: An air conditioner includes an indoor and outdoor units connected by a power supply line, a common line, and a signal line. The indoor unit includes a first switch for connection between the power supply line and the signal line, and the outdoor unit includes: a second switch for connection between the power supply line and the outdoor unit; a smoother; and a third switch to connect the signal line and a resistor when in an off state, and be open when in an on state, the resister being connected to the second switch. When the outdoor unit starts, the first switch is turned on with the third switch in the off state to allow flow of an inrush current for charging the smoother and, after which, the second switch is turned on and subsequently the first switch is turned off and the third switch is turned on.

Abstract: An outdoor unit includes a casing with an inlet in a back surface and an outlet in a front surface, a fan in the casing which draws air in the inlet and blows air out the outlet, a compressor in the casing, and a partition plate partitioning the interior into a machine room with the compressor and a blower room with the fan. A control board is installed horizontally on top of the partition plate across the machine room and the blower room, an electric component box covers the control board, a heat-generating component on the blower room side of the control board drives the compressor and the fan, and a cooler connects to the heat-generating component and includes fins exposed from the electric component box. A curved vertical separation surface is between the electronic component and the blower room, and between the electronic component and the back surface.

Abstract: An outdoor unit includes a casing with an inlet formed in a back surface and an outlet formed in a front surface, a fan accommodated in the casing which draws in air from the inlet and blows out the air from the outlet, a compressor accommodated in the casing which compresses a refrigerant, a partition plate partitioning the interior of the casing into a machine room in which the compressor is installed and a blower room in which the fan is installed, a control board installed horizontally on the top of the partition plate across the machine room and the blower room, an electric component box covering the control board, a heat-generating component installed on the blower room side of the control board which drives the compressor and the fan, and a cooler connected to the heat-generating component and including a plurality of fins exposed from the electric component box.

Abstract: A power converting apparatus includes: a first arm including a switching element and a switching element connected in series; a second arm including a switching element and a switching element connected in series, the second arm being connected in parallel with the first arm; a reactor having one end connected to the switching element and the switching element and an opposite end connected to an alternating-current power supply; and a smoothing capacitor connected in parallel with the first arm and the second arm. The loss characteristic of the switching element and the second switching element that occurs in each switching event is better than the loss characteristic of the switching element and the switching element that occurs in each switching event.

Abstract: A refrigeration cycle apparatus includes a partition plate that partitions the inside of a housing of an outdoor unit into a blower chamber and a machine chamber, a reactor attached to the partition plate on a side of the machine chamber, a fixing member that fixes the reactor to the partition plate, and a plate-like first heat transfer member provided between the reactor and the partition plate, and in the refrigeration cycle apparatus, the first heat transfer member is provided between the partition plate and the reactor, and the thermal resistance of the first heat transfer member is smaller than the thermal resistance of the fixing member.

Abstract: A power converting apparatus includes: a boost circuit including a reactor supplied with first voltage output from an alternating-current power supply, a first leg including first upper-arm and lower-arm switching elements connected in series, and a second leg connected in parallel with the first leg and including second upper-arm and lower-arm switching elements connected in series, and boosting the first voltage; a first voltage detecting unit detecting the first voltage; a smoothing capacitor smoothing voltage output from the boost circuit; and a second voltage detecting unit detecting second voltage smoothed by the smoothing capacitor. When the second voltage is larger than the first voltage and is lower than or equal to twice the first voltage, a width of a second drive pulse to turn on the first upper-arm switching element is larger than a width of a first drive pulse to turn on the first lower-arm switching element.

Abstract: A motor drive apparatus includes: inverter modules equivalent in number to phases of a motor; and a control unit that generates a PWM signal for driving the inverter modules by using PWM. Each of the inverter modules includes: a plurality of pairs of switching elements, each pair of switching elements including two switching elements connected in series; a drive circuit; and a protection circuit. The plurality of pairs of switching elements is connected in parallel, and power GNDs that are reference terminals of the plurality of pairs of switching elements, a control GND that is a reference terminal of the drive circuit, and a terminal for overcurrent fault input in the protection circuit are independently exposed to the outside. The power GNDs and the control GND are connected to a single point on a printed circuit board by a wiring pattern.

Abstract: An AC-DC converting apparatus includes: a boost circuit including a reactor supplied with power supply voltage output from an alternating-current power supply, a first leg including a first upper-arm element and a first lower-arm element connected in series, and a second leg connected in parallel with the first leg and including a second upper-arm element and a second lower-arm element connected in series, and boosting the power supply voltage; and a first voltage detecting unit detecting the power supply voltage. When the power supply voltage is positive, the AC-DC converting apparatus causes the first lower-arm element and the second upper-arm element to perform boosting operation alternately every power supply cycle that is cycle of the power supply voltage, and when the power supply voltage is negative, the AC-DC converting apparatus causes the first upper-arm element and the second lower-arm element to perform boosting operation alternately every power supply cycle.

Abstract: A power conversion device includes: a rectifying unit rectifying an AC voltage output from an AC power supply; a booster circuit boosting an output voltage of the rectifying unit; a control unit causing the booster circuit to perform synchronous rectification; and a smoothing capacitor smoothing an output voltage of the booster circuit. The booster circuit is constituted by connecting a plurality of chopper circuits in parallel to each other, the chopper circuits each including an upper arm switching element and a lower arm switching element connected in series to a reactor connected to the rectifying unit, and the control unit generates a drive pulse causing the upper arm switching element to be turned on when a reverse current flows through the upper arm switching element.

Abstract: An AC-DC converting apparatus includes: a boost circuit including a reactor supplied with power supply voltage output from an alternating-current power supply, a first leg including a first upper-arm element and a first lower-arm element connected in series, and a second leg connected in parallel with the first leg and including a second upper-arm element and a second lower-arm element connected in series, and boosting the power supply voltage; and a first voltage detecting unit detecting the power supply voltage. When the power supply voltage is positive, the AC-DC converting apparatus causes the first lower-arm element and the second upper-arm element to perform boosting operation alternately every power supply cycle that is cycle of the power supply voltage, and when the power supply voltage is negative, the AC-DC converting apparatus causes the first upper-arm element and the second lower-arm element to perform boosting operation alternately every power supply cycle.

Abstract: An electric-motor driving apparatus according to the present invention is the electric-motor driving apparatus that drives an electric motor having a winding structure in which a first multi-phase winding and a second multi-phase winding are wound and includes a first DC/AC converter connected to the first multi-phase winding and applying a multi-phase alternating-current voltage to the electric motor, a second DC/AC converter connected to the second multi-phase winding and applying a multi-phase alternating-current voltage to the electric motor, a first three-phase switching unit to perform connecting and disconnecting between phases of the first multi-phase winding, a second three-phase switching unit to perform connecting and disconnecting between phases of the second multi-phase winding, and a winding switching unit to perform connecting and disconnecting between the first multi-phase winding and the second multi-phase winding.

Abstract: A motor system according to the present invention includes: a motor including a first winding portion and a second winding portion, the second winding portion having a larger number of turns than the first winding portion; a first inverter connected to the first winding portion; and a second inverter connected to the second winding portion.

Abstract: A power converting apparatus includes: a first arm including a switching element and a switching element connected in series; a second arm including a switching element and a switching element connected in series, the second arm being connected in parallel with the first arm; a reactor having one end connected to the switching element and the switching element and an opposite end connected to an alternating-current power supply; and a smoothing capacitor connected in parallel with the first arm and the second arm. The loss characteristic of the switching element and the second switching element that occurs in each switching event is better than the loss characteristic of the switching element and the switching element that occurs in each switching event.

Abstract: Provided is a motor driving apparatus used for driving a motor including a first winding group and a second winding group to which three-phase alternating-current voltages are applied. The motor driving apparatus includes a first inverter and a second inverter; the first inverter applies an alternating-current voltage to the first winding group; and the second inverter applies an alternating-current voltage to the second winding group. A first induced voltage detector, a second induced voltage detector, and a third induced voltage detector are provided as voltage detectors for detecting induced voltages induced either in the first winding group or in the second winding group.

Abstract: A power converting apparatus includes: a boost circuit including a reactor supplied with first voltage output from an alternating-current power supply, a first leg including first upper-arm and lower-arm switching elements connected in series, and a second leg connected in parallel with the first leg and including second upper-arm and lower-arm switching elements connected in series, and boosting the first voltage; a first voltage detecting unit detecting the first voltage; a smoothing capacitor smoothing voltage output from the boost circuit; and a second voltage detecting unit detecting second voltage smoothed by the smoothing capacitor. When the second voltage is larger than the first voltage and is lower than or equal to twice the first voltage, a width of a second drive pulse to turn on the first upper-arm switching element is larger than a width of a first drive pulse to turn on the first lower-arm switching element.

Abstract: A refrigeration cycle apparatus includes a partition plate that partitions the inside of a housing of an outdoor unit into a blower chamber and a machine chamber, a reactor attached to the partition plate on a side of the machine chamber, a fixing member that fixes the reactor to the partition plate, and a plate-like first heat transfer member provided between the reactor and the partition plate, and in the refrigeration cycle apparatus, the first heat transfer member is provided between the partition plate and the reactor, and the thermal resistance of the first heat transfer member is smaller than the thermal resistance of the fixing member.

Abstract: An electric-motor driving apparatus is used to drive an electric motor including a plurality of winding groups constituting a three-phase winding. The electric-motor driving apparatus includes a switch that switches connection of windings of a first winding group and a second winding group, an inverter that drives an electric motor, and a controller that controls the inverter and the switch.

Abstract: There are provided the same number of inverter modules as the number of phases of a motor, and an inverter control unit that generates PWM signals used to drive the inverter modules in PWM. Three phase outputs from each of the inverter modules are coupled to form a phase output signal for one phase of the motor while capacitors are mounted between control GNDs of the inverter modules and power GNDs of the inverter modules. Consequently, even if a surge voltage is generated in a GND wiring at the time of a switching operation of switching elements in the inverter modules, the application of the surge voltage to the switching elements can be suppressed.

Abstract: A motor drive apparatus includes: inverter modules equivalent in number to phases of a motor; and a control unit that generates a PWM signal for driving the inverter modules by using PWM. Each of the inverter modules includes: a plurality of pairs of switching elements, each pair of switching elements including two switching elements connected in series; a drive circuit; and a protection circuit. The plurality of pairs of switching elements is connected in parallel, and power GNDs that are reference terminals of the plurality of pairs of switching elements, a control GND that is a reference terminal of the drive circuit, and a terminal for overcurrent fault input in the protection circuit are independently exposed to the outside. The power GNDs and the control GND are connected to a single point on a printed circuit board by a wiring pattern.

Abstract: Provided is a motor driving apparatus used for driving a motor including a first winding group and a second winding group to which three-phase alternating-current voltages are applied. The motor driving apparatus includes a first inverter and a second inverter; the first inverter applies an alternating-current voltage to the first winding group; and the second inverter applies an alternating-current voltage to the second winding group. A first induced voltage detector, a second induced voltage detector, and a third induced voltage detector are provided as voltage detectors for detecting induced voltages induced either in the first winding group or in the second winding group.