Mitsubishi Electric Corporation

Shinichiro Ura

Koichi Arisawa

Keisuke Uemura

Yosuke Shinomoto

Takuya Shimomugi

Shigeo Umehara

Makoto Tanikawa

Shun Miyamori

Keiichiro Shizu

An electric motor drive device includes: a main substrate mounted with a power supply circuit that generates, on the basis of alternating-current power supplied from an alternating-current power supply, a drive power to drive a compressor motor; a plurality of connection switching relays that perform switching between connections for the compressor motor; a small substrate mounted with the connection switching relays; a relay drive circuit that switches the connection switching relays; lead wires that connect the compressor motor and the small substrate to the power supply circuit; and lead wires that connect the small substrate and the compressor motor.

Electric motor drive device and outdoor unit of air conditioner

An electric motor drive device includes a wire-connected-state switching unit to switch a wire connected state of stator windings of an electric motor to either a delta connected state or a star connected state, an inverter to drive the electric motor, and a relay-voltage detection circuit to detect a relay voltage (VR) that is a power-supply voltage of the wire-connected-state switching unit, and to deactivate the inverter when the relay voltage (VR) is decreased below a threshold.

Electric motor drive 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 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

An interleaved converter configured by connecting a plurality of switching converter circuits in parallel includes an inter-inductor switch that selects whether inductors are connected in series, an input side switch that is connected to a connection point of the inductor and the inter-inductor switch and selects whether electric power is supplied from a rectifier circuit to the inductor side, an output side switch that is connected to a connection point of the inductor and the inter-inductor switch and selects whether electric power is supplied from the inductor to the diode side, and a control circuit that controls the inter-inductor switch, the input side switch, and the output side switch.

Growing community of inventors

Tokyo, Japan

Shinichiro Ura