Mitsubishi Electric Corporation

Hitachi, Ltd.

Mitsubishi Denki Kabushiki Kaisha

Hitachi Microcomputer Engineering, Ltd.

Mitsubishi Corporation

Mitsubishi Electric Building Techno-Service Co., Ltd.

Takahiko Kobayashi

Noriyuki Wada

Daiki Matsuura

Kiyoharu Anzai

Keita Hatanaka

Shinsaku Kusube

Masaki Kono

Kazunori Hatakeyama

Keisuke Uemura

Yoshihiko Kimpara

Yoshihiko Kinpara

Yasuhiko Wada

Yoshihiro Taniguchi

Daisuke Ito

Takashi Hashimoto

Akihiko Iwata

Hidetoshi Kitanaka

Yosuke Shinomoto

Takahiro Inoue

Hisanori Yamasaki

Masahiro Iezawa

Shigeo Takata

Sho Kato

Manabu Yoshimura

Taichiro Tamida

Takanori Koike

Hiroyuki Maezawa

Shuhei Koyama

Kazuyoshi Watabu

Masahiro Fukuta

Ichiro Naito

Satoru Terashima

Kazuyoshi Shinozaki

Keiwa Tsukano

Fumiaki Takagi

Syoichi Kawamoto

Takumi Oonuma

A driving apparatus includes: an inverter unit generating a three-phase alternating-current voltage from a direct-current voltage in accordance with a drive signal based on a voltage command and outputting the three-phase alternating-current voltage to a permanent-magnet motor, the permanent-magnet motor including a permanent magnet; a current detection unit detecting a motor current flowing through the permanent-magnet motor; and a control unit generating the voltage command to control an operation of the inverter unit and estimating a temperature of the permanent magnet to perform a protection operation on the inverter unit on the basis of the motor current and an overcurrent protection threshold. The control unit sets the overcurrent protection threshold on the basis of a magnet temperature estimated value of the permanent magnet and any one of a control computation period of the control unit, an output voltage frequency of the inverter unit, and a carrier frequency based on the output voltage frequency of the inverter unit.

Driving apparatus and air-conditioning apparatus

A refrigeration cycle apparatus includes a refrigerant circuit through which refrigerant circulates, a control box in which equipment for controlling the refrigeration cycle apparatus is accommodated, and a refrigerator for cooling a heat emitting body exposed from an opening of the control box. The heat emitting body is the equipment accommodated in the control box. The refrigerator includes a cooling body in contact with the heat emitting body, and a refrigerant pipe through which the refrigerant circulating through the refrigerant circuit passes to cool the cooling body. The refrigerant pipe is in contact with the cooling body. The pipe contact surface is different from the heating-body contact surface. The cooling body has a recessed portion at which the cooling body and the heat emitting body are not in contact with each other. The recessed portion is formed in the heating-body contact surface and spaced from the control box.

Refrigeration cycle apparatus

Provided is an electrostatic capacitance detection device including: an electrode pair including a pair of electrodes, the electrode pair being arranged inside a compressor configured to compress refrigerant; a capacitor being connected in series to the electrode pair; an inverter having one of power lines connected to one end of series-connected electrode pair and capacitor, and is configured to drive the compressor, the power lines being used for driving the compressor; and a voltage detecting unit configured to measure a voltage between the pair of electrodes of the electrode pair.

Electrostatic capacitance detection device and power conversion apparatus

A power conversion device includes a filter unit including an active noise canceler including an active element reducing low frequency components contained in common mode noise of noise and lower than a predetermined threshold frequency, and a passive filter including a passive element reducing normal mode noise of noise and high frequency components contained in the common mode noise of noise and equal to or higher than the threshold frequency. The active noise canceler includes a choke coil having a primary winding to which a first alternating current power is supplied and a secondary winding outputting a current, a filter circuit reducing a high frequency region of the current of the secondary winding, an amplifier circuit amplifying output of the filter circuit and securing a required amount of the current, and a current injection circuit injecting output of the amplifier circuit to each phase of the first alternating current power.

Power conversion device

To estimate a magnet magnetic flux or a magnet temperature with higher accuracy during a three-phase short circuit operation, than in a case only a d-axis current is used. A control device includes a phase short circuit unit for short-circuiting three-phase terminals of a permanent-magnet-type synchronous machine having a permanent magnet. During three-phase short circuit operation in which the three-phase terminals are short-circuited by the phase short circuit unit and the permanent-magnet-type synchronous machine is operated, the control device estimates a magnet state of the permanent magnet on the basis of a d-axis current, a q-axis current and a magnetic characteristic.

Control device and control method

A power converting apparatus for applying to a load an alternating-current voltage converted from a direct-current voltage includes an inverter that receives a PWM signal and applies the alternating-current voltage to the load and an inverter control unit that generates the PWM signal and supplies the PWM signal to the inverter. The frequency of the PWM signal is an integer multiple of the frequency of the alternating-current voltage. The alternating-current voltage includes a plurality of positive pulses and a plurality of negative pulses in one cycle of the alternating-current voltage. The number of the positive pulses and the number of the negative pulses are equal.

Power converting apparatus and heat pump apparatus

A power converting apparatus includes: an inverter converting a direct-current voltage supplied from a power supply unit into an alternating-current voltage and outputting the alternating-current voltage to a motor; and an inverter control unit outputting synchronous PWM (Pulse Width Modulation) signals for driving switching elements of the inverter. A frequency of the synchronous PWM signals is periodically varied when periodic pulsation occurs in a load connected to the motor.

Power converting apparatus and heat pump device

Provided is a power conversion device including: a step-up converter unit, including a reactor to which a DC voltage is to be input, a switching element connected to the reactor in parallel, and a backflow prevention element connected to the reactor in series; a smoothing capacitor configured to smooth an output voltage from the step-up converter unit; an inverter unit configured to convert the output voltage smoothed in the smoothing capacitor into an AC voltage; a dew condensation state detection unit configured to detect a state of dew condensation, which occurs due to a cooler configured to cool the step-up converter unit and the inverter unit; and a control unit configured to control an operation of the step-up converter unit, wherein the control unit includes: a determination unit configured to determine the state of dew condensation detected by the dew condensation state detection unit; and a step-up control unit configured to control a step-up operation of the step-up converter unit based on a result of determination made by the determination unit.

Power conversion device and air-conditioning apparatus

A synchronous machine control device is provided with a magnet state outputter that estimates a magnetic flux of a permanent magnet forming the magnetic field of a synchronous machine. In a magnet state correction value calculation mode, the magnet state outputter calculates a magnet state correction value. In a magnet state estimation mode, the magnet state outputter obtains, from a magnet state estimation device, a magnetic flux estimation value of the permanent magnet under a given condition of a magnetic flux command and a &#x3b4;-axis current command and controls a magnet state corrector to correct the magnetic flux estimation value of the permanent magnet obtained by the magnet state estimation device, by use of the magnet state correction value.

Synchronous machine control device

A synchronous machine control apparatus for correcting a rotor position error that is a difference between a rotor position of a synchronous machine and a rotor position detected by a position detection unit is provided with a current control device for performing control in such a way that respective current command values and respective current detection values in a generation direction (&#x3b3; axis) of an armature interlinked magnetic flux and in a direction perpendicular (&#x3b4; axis) to the generation direction of the armature interlinked magnetic flux coincide with each other and with a magnetic flux calculation device for calculating a phase of an armature interlinked magnetic flux, based on an armature current detection value of the synchronous machine and an armature voltage command value therefor; the rotor position error is corrected based on the &#x3b3;&#x3b4;-axis current command values and a phase of the armature interlinked magnetic flux.

Synchronous machine control apparatus

A synchronous machine controller includes a position detecting unit that detects a position of a rotor, a current detecting unit that detects an armature current, a current command generating unit that generates first and second current commands, a voltage command generating unit that generates a voltage command on the basis of the current commands, the position of the rotor, and the armature current, a power converting unit that outputs a voltage to the synchronous machine on the basis of the voltage command, a magnetic flux estimating unit that estimates an armature interlinkage flux on the basis of a rotational velocity calculated from a variation of the position of the rotor, the voltage command, and the armature current, and a magnet state estimating unit that estimates a magnetic flux or a temperature of the permanent magnet from the position of the rotor, the armature current, and the armature interlinkage flux.

Synchronous machine controller

A synchronous machine control apparatus is characterized by including a magnet condition estimation unit () that estimates the temperature or the magnetic flux of a permanent magnet that forms the magnetic field of a synchronous machine (), and is characterized in that the magnet condition estimation unit () coordinate-converts an armature current into currents on the &#x3b3;-&#x3b4; axis consisting of the &#x3b3; axis and the &#x3b4; axis that is perpendicular to the &#x3b3; axis, based on the rotor position and the estimated &#x3b3; axis, and estimates the temperature or the magnetic flux of the permanent magnet, based on the control command for the synchronous machine () and the &#x3b3;-&#x3b4; axis currents.

A control command generator that generates an armature interlinkage flux command and a torque current command by a torque command, a rotation speed, and an operation target command, includes a first flux command generator generating a first flux command by the toque command or the torque current command, a second flux generator generating a second flux command by the torque command or the torque current command and the rotation speed of the synchronous machine, a command allocation setting unit setting an allocation coefficient equivalent to an allocation ratio of the two first and second flux commands by the operation target command, a flux command adjuster outputting an armature interlinkage flux command by the two flux commands and the allocation coefficient, and a torque current command generator generating the torque current command by the torque command and the armature interlinkage flux command.

A control device for an AC rotating machine having a current limiting function of protecting the AC rotating machine and a driving unit such as an inverter from over-current, in which the control device has the reliable current limiting function in driving the AC rotating machine with known or unknown electrical constant. In the control device, a frequency correction value arithmetic unit has an amplification gain computing element for computing an amplification gain based on an electrical constant of the AC rotating machine and an amplifier for computing a frequency correction arithmetic value based on the amplification gain computed by the amplification gain computing element and the current of the AC rotating machine, in which the frequency correction arithmetic value is outputted as a frequency correction value in a predetermined running state of the AC rotating machine.

Control device for AC rotating machine

A power conversion system includes a first power converter converting AC to DC, a second power converter converting DC to AC, a current detector detecting output current of the second power converter, a pulsation detector detecting a pulsating component associated with the AC to DC conversion of the first power converter from a pulsating component contained in at least any one of effective power, power, and apparent power of the second power converter, a voltage corrector outputting a correction amount correcting at least one of phase, frequency, and amplitude of a voltage output from the second power converter based on the pulsating component from the pulsation detector, and a voltage controller outputting a voltage instruction to be output from the second power converter based on the correction amount from the voltage corrector, wherein the second power converter converts DC to AC based on the voltage instruction from the voltage controller.

Growing community of inventors

Tokyo, Japan

Takahiko Kobayashi