Hitachi-johnson Controls Air Conditioning, Inc.

Rei Kasahara

Dongsheng Li

Hiroaki Kaneko

Takayuki Hashimoto

Kazumoto Urata

Koji Naito

Shin Miura

Kazuhiko Tani

Mikihito Tokudi

Takashi Oishi

Ken Kishita

Takashi Ooishi

Tatsuo Ando

Hiromichi Shinohara

Yoshiaki Kurita

In order to achieve a power conversion device with which a motor can be stably driven, a power conversion device is provided with: an inverter, which converts supplied DC voltage to an AC output voltage and supplies the AC output voltage to windings, and which, in accordance with the DC voltage, changes the saturation level at which the output voltage is saturated, in order to drive a motor equipped with a stator having the windings and a rotor having permanent magnets; and a controller which, when the output voltage is lower than the saturation level, increases the output current of the inverter such that a magnetic flux that weakens or strengthens the magnetic flux generated by the permanent magnets is generated in the windings. An air conditioner including the power conversion device is also disclosed.

Power conversion device and air conditioner

The present invention provides an outdoor unit for an air conditioner that can be constructed at low cost while reducing risk of malfunction. The outdoor unit has a compressor; a fan motor; a compressor driver board having a compressor inverter circuit and a compressor driver circuit; and a fan driver board having a fan inverter circuit and fan driver circuit. The compressor driver board has at least either: a shared control circuit that feeds a first switching signal for a compressor to the compressor driver circuit and feeds a second switching signal for a fan to the fan driver circuit; or a shared power source circuit that steps down a first DC voltage to a second DC voltage and supplies the second DC voltage to the compressor driver circuit and to the fan driver circuit.

Outdoor unit for air conditioner

The air conditioner has: an outdoor heat exchanger that exchanges heat between the air and a refrigerant flowing in the interior of this heat exchanger; an outdoor fan that blows air into the outdoor heat exchanger; an outdoor fan motor that rotationally drives the outdoor fan; an outdoor fan inverter that supplies a desired current to the outdoor fan motor; a current detector that detects the current flowing in the outdoor fan motor; and a control unit that controls the outdoor fan inverter such that the rotational frequency of the outdoor fan motor reaches a target rotational frequency. The control unit starts a defrosting operation of the outdoor heat exchanger on the basis of a detection value from the current detector during the heating operation.

Air conditioner

A controller of an inverter control apparatus includes an A/D conversion unit that performs digital conversion of an input signal when a signal for either an A/D converter start trigger or an A/D converter start trigger is input thereinto; a first inverter control unit that generates the A/D converter start trigger which starts the A/D conversion unit, based on A/D converter start timing information and a first carrier signal; a second inverter control unit that generates the A/D converter start trigger which starts the A/D conversion unit, based on A/D converter start timing information and a second carrier signal; and an A/D start factor selection unit that receives either the A/D converter start trigger or the A/D converter start trigger and selects an A/D start factor at a predetermined period timing of an operation period of the first carrier signal and the second carrier signal.

Inverter control apparatus and air conditioner

Growing community of inventors

Tokyo, Japan

Rei Kasahara