Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Makoto Tanikawa

Koichi Arisawa

Shigeo Umehara

Yosuke Shinomoto

Takuya Shimomugi

Keisuke Uemura

Shinichiro Ura

Tomomi Higashikawa

Takashi Yamakawa

Yuji Takayama

Mitsuo Kashima

Hitoshi Tanifuji

Hiroaki Suzuki

Masato Handa

Isao Kawasaki

Yoshihiro Iwasaki

Yoshihiko Kikkawa

Takahiro Ishigami

Norikazu Ito

Masahito Mori

Katsuhiko Saito

Hideki Takahara

Akiyoshi Muramatsu

Takahiro Hirata

Ichiro Minejima

An inverter control device that controls an inverter unit that converts a DC voltage from a converter unit to an AC voltage and supplies the AC voltage to the DC motor includes a storage unit that stores therein information regarding a synchronization-loss limit; a synchronization-loss limit-current calculation unit that calculates the limitation value on the synchronization-loss limit current on the basis of the magnet temperature of the DC motor, the bus voltage to be applied to the inverter unit, and the information regarding a synchronization-loss limit; and a control unit that compares the primary current to be input to the converter unit with the limitation value and that, when the primary current exceeds the limitation value, outputs an adjustment command to adjust the operating frequency of the DC motor such that the primary current becomes equal to or less than the limitation value.

Inverter control device and air conditioner

A switch device in a power conversion device is located between a power supply and a load, wherein the power conversion device includes a shunt resistance and a switching element and is capable of executing stable control, the switch device includes a switching element that includes a gate terminal, a gate drive circuit that applies a drive voltage Vto a gate terminal of the switching element, and a control unit that generates a drive signal to the gate drive circuit, wherein a value obtained by subtracting a threshold voltage Vof the switching element from the drive voltage Vto be applied to the gate terminal of the switching element is greater than a product of a resistance value R+Rfrom an emitter of the switching element to a negative electrode of the gate drive circuit and a maximum current value Ithat flows through the switching element.

Switch device, power conversion device, motor drive device, air blower, compressor, air conditioner, refrigerator, and freezer

A power converting apparatus includes a rectifier converting alternating-current power from an alternating-current power supply into direct-current power; a short-circuit unit short-circuiting the alternating-current power supply via a reactor; and a controlling unit controlling the short-circuit unit in a half cycle of the alternating-current power supply. A correction amount using inductance of the reactor is set in the controlling unit, and the controlling unit changes, using at least a detection value of a power supply current and the correction amount, an ON time and an OFF time of a plurality of switching pulses, and controls, using changed switching pulses, an ON/OFF operation of the short-circuit unit.

Power conversion device with correction of reactor inductance based on detected current

The device includes a rectifier circuit that converts alternating-current power from an alternating-current power supply into direct-current power; a short-circuit unit that short-circuits the alternating-current power supply via a reactor connected between the alternating-current power supply and the rectifier circuit; and a control unit that controls an ON/OFF operation of the short-circuit unit during a half cycle of the alternating-current power supply. The control unit includes a driving-signal generating unit that generates a driving signal Sa that is a switching pulse to control the ON/OFF operation of the short-circuit unit; and a pulse dividing unit that divides the driving signal Sa into a plurality of switching pulses.

Power converting device

A power converting apparatus includes a rectifier that converts alternating-current power from an alternating-current power supply into direct-current power, a short-circuit unit that short-circuits the alternating-current power supply via a reactor, and a control unit that controls a short-circuit operation of the short-circuit unit. The control unit changes the number of times of the short-circuit operation during a half cycle of the alternating-current power supply on the basis of a load condition and sets a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply after the change of the number of times of the short-circuit operation to be different from a period from a start to an end of the short-circuit operation during the half cycle of the alternating-current power supply before the change of the number of times of the short-circuit operation.

AC/DC power converting apparatus with AC source shortcircuiting for power factor correction and harmonic suppression

A power conversion device includes an inverter configured by arms including phase upper-arm switching elements and phase lower-arm switching elements, a power-supply shunt resistor, lower-arm shunt resistors, and a control unit that generates drive signals corresponding to the phase upper-arm switching elements and the phase lower-arm switching elements from detection values of the voltage detectors. The power conversion device changes a ratio of time in which all of the upper-arm switching elements are in an ON state and time in which all of the lower-arm switching elements are in the ON state in one cycle of switching of the inverter according to a modulation ratio.

Power conversion device, motor driving device including power conversion device, blower and compressor including motor driving device, and air conditioner, refrigerator, and freezer including blower and compressor

The power conversion device includes a power-supply shunt resistance provided between an inverter and the negative-voltage side of a DC power supply, respective-phase lower-arm shunt resistances provided between the power-supply shunt resistance and respective-phase lower-arm switching elements, a first overcurrent detection unit performing overcurrent detection on a current that flows through the power-supply shunt resistance on the basis of a power-supply shunt-resistance voltage, and a second overcurrent detection unit performing overcurrent detection on each current that flows through the respective-phase lower-arm shunt resistances on the basis of respective-phase lower-arm voltages, wherein overcurrent detection is performed on each phase current using either one of the overcurrent detection result of the first overcurrent detection unit and the overcurrent detection result of the second overcurrent detection unit.

Power conversion device, motor drive device including power conversion device, air blower and compressor including motor drive device, and air conditioner, refrigerator, and freezer including air blower and compressor

A power conversion device includes a power-supply shunt resistance that is provided between an inverter and the negative-voltage side of a DC power supply, and respective-phase lower-arm shunt resistances that are provided between the power-supply shunt resistance and respective-phase lower-arm switching elements. Respective-phase lower-arm voltages, that are respective voltages between the negative-voltage side of the DC power supply and connection points between the respective-phase lower-arm switching elements and the respective-phase lower-arm shunt resistances, are detected to calculate respective-phase currents that flow through a load device in accordance with detection values of the respective-phase lower-arm voltages, and to control a carrier frequency of a carrier signal, which serves as a reference frequency of each drive signal, according to a change in a specific control parameter A.

Power conversion device and motor drive device including power conversion device

The power conversion device includes a power-supply shunt resistor provided between a negative voltage side of a DC power supply and an inverter and phase lower-arm shunt resistors respectively provided between phase lower-arm switching elements of two arms among three arms and the power-supply shunt resistor. The power conversion device detects voltages between connection points of the phase lower-arm switching elements and the phase lower-arm shunt resistors and a negative voltage side of the DC power supply and calculates, on the basis of detection values of the voltages, phase currents flowing to a load device.

Power conversion device and motor driving device

A power converter includes step-up means for varying a voltage applied by a power supply to a predetermined voltage, commutating means for performing a commutation operation for allowing a current flowing through the step-up means to flow through a second path, smoothing means for smoothing a voltage related to outputs of the step-up means and the commutating means to produce power and supplying the power to a load side, and control means for performing control related to voltage varying, such as stepping up, by the step-up means and controlling the commutation operation of the commutating means on the basis of at least one of a voltage and a current related to the step-up means.

Power converter and refrigerating and air-conditioning apparatus

Provided is an alternating-current direct-current converter capable of controlling a harmonic current and improving a power factor at reduced costs. The alternating-current direct-current converter includes two capacitors connected in series between output terminals of a rectifier; a first switch connected between one input terminal of the rectifier and a connection point of the capacitors; a second switch connected between the other input terminal of the rectifier and the connection point of the capacitors; a voltage detector which detects terminal voltages of the capacitors; a current detector which detects a current input from the alternating current power supply; and a control means which drives and controls the first switch and the second switch, in which the control means drives and controls the first switch and the second switch such that the terminal voltages of the capacitors are fixed and a power supply power factor is improved using an active power component and a reactive power component obtained by conversion of detection results of the current detector and detection results of voltage detector.

Alternating-current direct-current converter and electric motor driver

A rectifier connected with an AC source through a reactor, a plurality of capacitors connected in series between output terminals of the rectifier, first switching means connected between one input terminal of the rectifier and a connection point of a plurality of capacitors, second switching means connected between the other input terminal of the rectifier and the connection point of a plurality of capacitors, and a plurality of diodes connected with the plurality of capacitors in inverse-parallel are provided.

AC-DC converter, method of controlling the same, motor driver, compressor driver, air-conditioner, and heat pump type water heater

Provided are, a converter section ( ) which converts a commercial AC voltage (V ) into a DC voltage (V ); an inverter section ( ) which converts the DC voltage (V ) into an output AC voltage (V ) of a predetermined frequency by a pulse-width modulation system based on an assigned PWM width, and supplies the output AC voltage (V ) to a compressor motor ( ). Further, an instantaneous DC voltage detecting section ( ) detects an instantaneous DC voltage (V ); and an arithmetic processing section ( ) corrects the PWM width so as to maintain the output AC voltage (V ) at a desired value following the variation in the instantaneous DC voltage (V ). It is possible to operate a compressor motor ( ) in an optimum state of load characteristics and efficiency.

Inverter control apparatus

An apparatus which secures a heat sink to an electrical component connected to a circuit board, including a first outer cover which engages a portion of the heat sink and a portion of the circuit board. In addition, the first outer cover encloses the electrical component, and the electrical component has at least two pins, a first surface facing the circuit board, and a second surface facing the heat sink. Further, a majority of heat dissipating surfaces of the heat sink are outside a space enclosed by the first outer cover and the circuit board.

Growing community of inventors

Tokyo, Japan

Makoto Tanikawa