Mitsubishi Electric Corporation

Ebara Corporation

Takashi Yamakawa

Koichi Arisawa

Takuya Shimomugi

Yosuke Shinomoto

Keisuke Uemura

Kenji Iwazaki

Shigeo Umehara

Kazunori Hatakeyama

Shinsaku Kusube

Akihiro Tsumura

Yuji Takayama

Kenta Yuasa

Shinya Toyodome

Noriyuki Matsubara

Keisuke Mori

Makoto Tanikawa

Tomomi Higashikawa

Atsushi Tsuchiya

Takayuki Kato

Norikazu Ito

Ikuro Suga

Satoru Ichiki

Shinya Matsushita

Keiichiro Shizu

Tomohiro Kutsuki

Tsutomu Makino

Shota Kamiya

Shunsuke Kubota

Naohide Tsuchimoto

Makoto Kasugai

Esao Yamada

Kentaro Orita

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.

Heat pump apparatus, air conditioner, and refrigerator

An outdoor unit includes a housing having a front surface formed with an outlet and a back surface facing the front surface, an airflow flowing through the outlet; a substrate horizontally placed in the housing, an electric component being mounted on the substrate; and a heat dissipator including a plurality of fins, each of the fins having a heat dissipation surface, the heat dissipator dissipating, due to the airflow, heat generated by the electric component. The heat dissipation surface of each of the fins is parallel to the back surface or is angled at greater than 0 degrees and less than 90 degrees relative to the back surface in top view.

Outdoor unit

An outdoor unit includes: a housing; a compressor placed in the housing; a heat exchanger placed in the housing; and a blower placed in the housing, the blower admitting air from outside the housing and passing the air through the heat exchanger. Furthermore, the outdoor unit includes: a partition plate partitioning the housing into a compressor chamber and a blower chamber; a board on which an electronic component is mounted; a heat dissipator placed in the blower chamber and adjacent to the partition plate, the heat dissipator including a base and a plurality of fins, the base having a fin formation surface, the fins projecting from the fin formation surface, the heat dissipator dissipating heat of the electronic component; and a duct covering the heat dissipator. When the fins are viewed from the fin formation surface side, the fins extend toward the blower side from the partition plate side.

A power converting apparatus includes a first arm including a switching element and a switching element connected in series, a second arm connected in parallel with the first arm and including a switching element and a switching element connected in series, a reactor having one end connected to the switching element and the switching element and the other end connected to a single-phase alternating-current power supply, and a smoothing capacitor connected in parallel with the first arm and the second arm. The power converting apparatus includes a driving circuit driving the switching element, a bootstrap circuit, and a diode adjusting a power supply voltage, wherein a first voltage at which a forward current starts to flow to the diode is lower than a second voltage at which a forward current starts to flow in a body diode formed in the second switching element.

Power converting apparatus, motor driving apparatus, and air conditioner

An outdoor machine includes a housing including a front panel with an opening formed therein; a blower disposed in the housing; a bell mouth disposed in the outer periphery of the blower and connected to the opening; a control board on which an electric component is mounted, the control board being provided in the housing; a heat radiation part that radiates heat generated by the electric component; and a vent deflector that covers the heat radiation part, and forms a ventilation flue through which air generated by the blower flows in the heat radiation part, in which the vent deflectoris not provided in a region between a virtual plane S and the front panel, the virtual plane S covering the entire periphery of an edge of the bell mouth and extending in parallel with the front panel.

Outdoor machine and air conditioner

An air conditioner includes a compressor to compress a refrigerant used in a refrigeration cycle, a converter to generate a DC voltage, an inverter to generate three-phase AC voltages from the DC voltage, a motor to produce a driving force for driving the compressor with a plurality of coils, the three-phase AC voltages being applied to the coils, a connection switching unit to switch connection states of the coils between a first connection state and a second connection state, and a controller to detect an abnormality of the connection switching unit.

Air conditioner and driving device

An over-current protection circuit for a motor capable of selecting one of a plurality of connection states has a plurality of decision circuits, a combining circuit, and a nullifying circuit. The combining circuit combines results of the comparisons in the plurality of decision circuits. The nullifying circuit nullifies part of the comparisons in the plurality of decision circuits. The number of outputs of the over-current protection circuit is one, so that for controlling the driving and stopping of the inverter needs just one terminal is required for receiving the output of the combining circuit. Moreover, because the over-current protection circuit is formed of hardware, the protection can be performed at a high speed.

Motor driving apparatus

A motor driving device is a device for driving a motor including stator windings, includes: a connection switching unit that is connected to the stator windings, includes circuits including semiconductor switches, and switches connection condition of the stator windings to either of first connection condition and second connection condition different from the first connection condition by setting the semiconductor switches to ON or OFF; and an inverter that supplies AC drive voltages to the stator windings.

Motor driving device and air conditioner

A power converter is connected between a power supply source of a first direct current power and a power supply destination of a second direct current power obtained by performing power conversion on the first direct current power. The power converter includes: a switching element; a reactor; a first diode; a first capacitor; a second diode. The reactor is connected to a first end of the switching element. The first end of the switching element and a first end of the reactor are connected to a first connection point. A cathode of the first diode is connected to a second end of the reactor. The cathode of the first diode and the second end of the reactor are connected to a second connection point. The second diode includes an anode connected to the first connection point and a cathode connected to the power supply destination.

Power converter

An air conditioner includes a compressor to compress a refrigerant used in a refrigeration cycle, a converter to generate DC voltage, an inverter to generate three-phase AC voltage from the DC voltage, a motor to generate driving force to drive the compressor by using a plurality of coils to which the three-phase AC voltage is applied, a connection switching unit to switch connection states of the plurality of coils, and an outdoor control device to control the connection switching unit. The outdoor control device restricts the switching of the connection states when a switching count of the connection states exceeds a count threshold value.

Air conditioner

A motor driving device that is a device for driving a motor including stator windings, includes: a connection switching unit that includes relays as mechanical switches connected to the stator windings and excitation coils opening or closing the relays by being energized or non-energized with excitation current and switches connection condition of the stator windings to either of first connection condition (star connection) and second connection condition (delta connection) different from the first connection condition by opening or closing the relays; and an inverter that supplies AC drive voltages to the stator windings.

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.

Power converting apparatus, motor drive apparatus, and air conditioner

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.

Power converting apparatus, motor drive control apparatus, blower, compressor, and air conditioner

A motor drive system can detect a misconnection. A motor drive system for driving a motor including a plurality of stator windings includes: an inverter that converts a DC voltage supplied from a DC voltage source into an AC voltage and applies the AC voltage to the motor; a connection switching device that is disposed between the inverter and the motor and can switch a connection state of the stator windings; and a controller that performs abnormality determination on a connection state of the connection switching device on the basis of a current value of a current flowing in each of the stator windings.

Motor drive system and air conditioner

In a motor driving apparatus having an inverter for driving a motor capable of switching between a star connection and a delta connection, when currents detected by winding current detecting elements detecting currents flowing through windings become excessive, the inverter is made to stop. Moreover, inverter output currents are calculated after removing a circulating current component at the time of the delta connection, from the winding currents detected by the winding current detecting elements, and the inverter is controlled using the calculated inverter output currents. Because over-current protection is performed based on the detected values of the winding currents, it is possible to prevent demagnetization taking account oSf the circulating current. Also, the inverter control is prevented from being affected by the circulating current in the delta connection. Accordingly, it is possible to reduce the number of the current detecting elements, and perform the over-current protection and control properly.

Growing community of inventors

Tokyo, Japan

Takashi Yamakawa