Mitsubishi Electric Corporation

Yasuhiko Wada

Keita Hatanaka

Hisanori Yamasaki

Akihiro Tsumura

Yuruki Okada

Kenji Takahashi

Hidetoshi Kitanaka

Keisuke Uemura

Kazunori Hatakeyama

Kazunori Sakanobe

Takahiko Kobayashi

Yuichi Shimizu

Junji Morimoto

Tsukasa Masumura

Yosuke Shinomoto

Shigeo Takata

Kenta Yuasa

Chitose Tanaka

Toshiki Asai

Akane Hongyo

Yuki Taniyama

Junki Ishizaki

A drive device includes a power converter, a first magnetic pole position identification unit, a second magnetic pole position identification unit, a subtractor, and a current control unit. The power converter supplies power to a main-side synchronous motor and a sub-side synchronous motor connected in parallel. The subtractor obtains an angular difference using the magnetic pole position of the rotor of the main-side synchronous motor identified by the first magnetic pole position identification unit and the magnetic pole position of the rotor of the sub-side synchronous motor identified by the second magnetic pole position identification unit. A magnetic flux current command compensation unit adjusts the absolute value of a magnetic flux current command based on the angular difference. The current control unit controls the power converter using a torque current command and the magnetic flux current command with the absolute value adjusted by the magnetic flux current command compensation unit.

Drive device, fluid utilization device, and air conditioner

A refrigerating and air-conditioning apparatus performs a defrosting operation. The refrigerating and air-conditioning apparatus includes a refrigerant circuit, a temperature sensor, and a heat generation control unit. In the refrigerant circuit, a compressor, a first heat exchanger, an expansion device, a second heat exchanger, and a four-way valve are connected to each other by pipes to allow refrigerant to circulate through the refrigerant circuit. The temperature sensor measures a temperature of the compressor. The heat generation control unit increases a temperature of the compressor when the heat generation control unit detects a decrease in a value measured by the temperature sensor in a defrosting operation performed on the first heat exchanger.

Refrigerating and air-conditioning apparatus

A failure diagnosis apparatus includes a controller to control drive of a motor, a wear estimator to estimate an amount of wear of a bearing of the motor based on a current that flows in the motor, and a failure notification unit to diagnose a failure of the motor based on the amount of wear of the bearing of the motor estimated by the wear estimator and to notify a user. When the wear estimator estimates the amount of wear of the bearing of the motor, the controller controls drive of the motor such that the motor is driven in a constant state.

Failure diagnosis apparatus, training apparatus, training method, and failure diagnosis system

A motor control device includes: a power converter to which a first motor and a second motor are connected in parallel, the power converter being configured to convert a direct-current voltage into an alternating-current voltage and supply the alternating-current voltage to the first motor and the second motor; a switching unit provided between the second motor and the power converter; a current detector configured to detect an electric current flowing through the first motor and the second motor; and a controller configured to control the power converter based on at least a current value detected by the current detector. The controller deactivates the power converter upon receiving from outside an abnormal step signal, attributed to the occurrence of an abnormality, that excludes a normal stop signal representing a stop command and switches the switching unit from an on state to an off state upon deactivation of the power converter.

Motor control device

A motor control device includes a power converter that supplies a three-phase voltage to two motors being connected in parallel, a three-phase power line that connects between one of the two motors and the power converter, a branch three-phase power line that connects between the other of the two motors and the power converter, a switching device having two switches that are provided on the branch three-phase power line, a current detection device that detects three-phase currents flowing in the two motors, and a controller. The controller performs a failure determination of the switching device by identifying a phase of a power line in which no current flows in the three-phase power line and the branch three-phase power line, and, when a failure is detected in one of the two switches in the failure determination, controls to change a state of the other switch, which operates normally, to coincide with a state of the failed switch.

Motor control device and air-conditioning apparatus having the same

An electric motor control device that drives and controls a plurality of electric motors connected in parallel, includes: a power conversion device; a current detection device; and a controller that includes a first control unit to perform first control on each of the plurality of electric motors based on the electric current, a second control unit to perform second control of controlling the plurality of electric motors such that an estimated speed of each of the plurality of electric motors obtained based on the current value follows the speed command value, and a switching determination unit to perform switching determination processing of switching between the first control performed by the first control unit and the second control performed by the second control unit according to drive information on at least one or more of the plurality of electric motors.

Electric motor control device

A motor control device includes: an inverter circuit configured to convert a direct-current voltage into an alternating-current voltage, and to supply the alternating-current voltage to a plurality of motors connected in parallel; current detectors configured to detect motor currents flowing through the respective motors; a relay provided between at least one of the plurality of motors and the inverter circuit; and a controller configured to change the number of motors to be driven. When one of two or more motors under driving is stopped, the controller lowers a current instruction value to the two or more motors under driving. When a monitor current that is the motor current detected by the current detector of the motor connected to the relay is decreased, the controller switches the relay from an on state to an off state.

Motor control device and air-conditioning device

An electric motor control device controls driving of electric motors connected in parallel with each other and includes a power converter converting power from a power supply, and supply the converted power to each of the electric motors, a switching device to be turned on to electrically connect the power converter and at least one of the electric motors and to be turned off to electrically disconnect the power converter and the at least one of the electric motors, a current detection unit detecting a current that flows in the electric motors, and a controller controlling the power converter on the basis of operation of the switching device, rotation frequency command values from an external device, and a value of the current detected by the current detection unit. The controller turns the switching device from off to on so that start timing of control is different for each electric motor.

A drive system includes a current detection unit that detects a current flowing to a main synchronous motor, and a current detection unit that detects a current flowing to a secondary synchronous motor. The drive system includes a magnetic pole position estimation unit that estimates the magnetic pole position of the rotor of the main synchronous motor, and a magnetic pole position estimation unit that estimates the magnetic pole position of the rotor of the secondary synchronous motor. The drive system includes a current control unit that outputs a voltage command, and a secondary torque current pulsating component extraction unit that extracts a pulsating component. The drive system includes a subtracter that determines an angle difference, and a magnetic flux current command determination unit that determines a magnetic flux current command.

Drive system, fluid utilization apparatus, and air conditioner

A motor control device includes an inverter configured by a plurality of arms, a smoothing unit supplying a direct-current voltage to the inverter, a shunt resistor inserted between a lower-arm switching element for each phase of the inverter and a negative-electrode side of the smoothing unit, a master motor current sensor outputting a voltage according to a current flowing in a first motor connected in parallel to the inverter, and a computing unit generating driving signals for a plurality of switching elements based on an output of the master motor current sensor and an output corresponding to a voltage drop on the shunt resistor.

Motor control device and air conditioner

A synchronous motor drive device drives a plurality of synchronous motors, and includes a power converter that converts power to supply power to the plurality of synchronous motors, a first switch device that electrically connects or disconnects between the power converter and each of the plurality of synchronous motors, and a controller that, based on a higher order command, performs stability judgment processing of the plurality of synchronous motors, determines the number of synchronous motors to be driven and a drive speed from among the plurality of synchronous motors, selects a synchronous motor corresponding to the number of the synchronous motors from among the plurality of synchronous motors, controls the first switch device corresponding to the selected synchronous motor to electrically connect the power converter to the synchronous motor and to supply the power, and instructs, to the power converter, the drive speed of the synchronous motor to be driven.

Synchronous motor drive device, air-sending device and air-conditioning device

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

A hybrid-vehicle power generator control apparatus includes an integrated control unit that issues a driving command and a control command to an engine control unit and an electric-power conversion system control unit, respectively, based on requested electric power requested by a load apparatus, and a limiter that limits the control command from the integrated control unit such that when rotation frequency of an electric power generator is same as or lower than a predetermined value, the value of torque generated by the electric power generator becomes smaller than the value of torque generated by an engine. A limitation of the control command by the limiter prevents torques of the engine and the electric power generator from stepping out of the stable operating points.

Hybrid vehicle power generation control apparatus

A hybrid drive system includes first and second power supply devices that supply direct-current power; first and second power storage devices are respectively connected to the first and second power supply devices so as to accumulate or discharge the direct-current power; a first load device that receives a supply of the direct-current power from the first power supply device and the first power storage device and drives a first load; and a second load device that receives a supply of the direct-current power from the second power supply device and the second power storage device and drives a second load. The hybrid drive system includes an inter-group contactor for electrically connecting and disconnecting input terminals of the first power storage device and the second power storage device.

Growing community of inventors

Tokyo, Japan

Yasuhiko Wada