Hitachi, Ltd.

Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi Appliances, Inc

Renesas Electronics Corporation

Hitachi-johnson Controls Air Conditioning, Inc.

Johnson Controls-hitachi Air Conditioning Technology (hong Kong) Limited

Hitachi Global Life Solutions, Inc.

Yasuo Notohara

Takahiro Suzuki

Yukio Kawabata

Kazuo Tahara

Yuhachi Takakura

Makoto Ishii

Tsunehiro Endo

Hiroshi Shinozaki

Yoshitaka Iwaji

Motoo Futami

Kazuaki Tobari

Dongsheng Li

Chikara Tanaka

Yoshiaki Kurita

Kouji Katou

Daisuke Maeda

Shigehisa Aoyagi

Wataru Hatsuse

Tatsuo Ando

Kiyoshi Sakamoto

Houng Joong Kim

Tadashi Fukushima

Hidefumi Shirahama

Ikuo Yamato

Tunehiro Endo

Koujirou Yamashita

Hiroo Nakamura

Satoshi Sumita

Toru Inoue

Tsunehiro Endou

Eri Maruyama

Kentaro Oi

Ryouichi Takahata

Yuuji Yamamoto

Tooru Kitayama

Yuji Mori

Motoo Morimoto

Shoji Takaku

Shigeru Kishi

Yuuji Funayama

Akihiro Tanba

Yoshiki Ito

Atsushi Okuyama

Kenji Tamura

Dong Sheng Li

Hiroki Umeda

An inverter, motor drive device and freezing device, with which it is possible to effectively suppress current beats in the event of over-modulation without requiring additional circuits. This motor driving device includes: a rectifier circuit that converts the AC voltage from an AC power supply into a DC voltage; a smoothing capacitor that smoothes the DC voltage output from the rectifier circuit; an inverter circuit that converts the DC voltage output from the smoothing capacitor into an AC voltage; and a controller that reduces the current beat component by estimating, using a phase locked loop process, the frequency, phase and amplitude of the current beat component in the output current of the inverter circuit, and corrects the voltage command to the inverter circuit on the basis of the estimated frequency, phase and amplitude.

Inverter and motor drive device, freezing device

A permanent magnet synchronous motor includes at least two series-connected windings for each phase, and is configured to be driven by selecting the windings using a multi-inverter driving device configured to switch between an inverter for low-speed drive and an inverter for high-speed drive. A ratio of an induced voltage constant of at least one group of windings constituting the windings for the high-speed drive and a d-axis inductance is larger than a ratio of an induced voltage constant of all the series-connected windings to the d-axis inductance.

Permanent magnet synchronous motor and winding-switching motor driving device, and refrigeration air conditioner and electric vehicle using same

A converter includes three AC reactors, a three-phase diode bridge, a plurality of smoothing capacitors connected in series between a DC output side of the three-phase diode bridge and a DC load, two flywheel diodes connected to positive and negative terminals on the DC side of the three-phase diode bridge, respectively. A reactor is inserted between the midpoint of the two flywheel diodes and the midpoint of the smoothing capacitors, three both-way energizing switches are arranged between the AC side of the three-phase diode bridge and the midpoint of the two flywheel diodes. The three both-way energizing switches are controlled to reduce higher harmonic components of power source current, and by the reactor interposed between the midpoint of the two flywheel diodes and the midpoint of the smoothing capacitors, reverse recovery currents of the three-phase diode bridge during turn-on of the three both-way energizing switches are suppressed.

Converter, motor driving module, and refrigerating apparatus

A control apparatus and a control method for an AC electric motor detect DC bus current plural times at predetermined intervals during first and second predetermined periods and multiply vectors having integrated values of detected values during respective periods as elements by an inverse matrix of a matrix having integrated values during respective periods of sine and cosine functions of output voltage phase of an inverter at the moment that detection is made as elements to thereby estimate reactive and active currents.

Control apparatus and control method for AC electric motor

The invention relates to a speed control method of a magnetic motor and is capable of providing a speed controller of the magnetic motor realizing highly stable, highly efficient and highly responsive control characteristics even around critical torque of the motor. When an excessive torque command value (or a q-axis commanded current value) greater than a torque maximum value (or a q-axis current) that can be outputted by the motor is required, an input of speed control is limited so that the q-axis commanded current value does not increase up to a limit value.

Speed controller of magnetic motor

The device is provided with an electric power conversion circuit including switching elements for converting a DC electric power to an AC electric power, a load connected to an output side of the electric power conversion circuit, means for detecting a current flowing through a DC side in the electric power conversion circuit, a voltage command value preparing means for controlling the operation of the switching elements in the electric power conversion circuit and a wire breaking detecting means. The wire breaking detection means judges a wire breaking in the load or an abnormality of any of the switching elements in the electric power conversion circuit by making use of a DC current detection value in a period when a current of maximum voltage phase or of voltage minimum phase of the electric power conversion circuit is flowing in a DC current.

Electric power conversion device, compressor motor with the device, and air conditioner with the motor

Provided is a control technique of a PWM conversion type power converter capable of compensating for a voltage error due to voltage drop mainly at a switching element and managing a switching time of a PWM signal at the same time, and capable of suppressing increase/decrease of software operation load and addition of a hardware circuit to the minimum. A semiconductor integrated circuit having a PWM signal generating unit which generates a PWM signal is provided with a PWM timer unit including a counter counting a pulse width of a pulse signal inputted from the outside with delay from a PWM signal, a register loading a counter value of the counter in synchronization with the PWM signal, and an A/D converting unit converting an analog signal serving as a source signal of the pulse signal inputted from the outside to a digital signal.

Semiconductor integrated circuit, PWM signal output device, and power conversion control apparatus

A converter includes a converter circuithaving a plurality of bridge-connected semiconductor switching devices for converting AC power into DC power, a smoothing condenser connected in parallel to the DC side of the converter circuit and a current detector provided in a condenser circuit to control a condenser current flowing through the smoothing condenser to be a set value. The condenser current is controlled to be the set value (e.g. zero) to thereby reduce the capacity of the smoothing condenser and make the converter small.

Converter and power converter that becomes it with the converter

A method controls a torque of an a. c. motor which does not cause a shortage of torque by using an economical current detection which estimates d- and q-axis currents Idc, Iqc from d. c. current IDC flowing through an input d. c. bus line of a power converter. A value of d- and q-axis motor currents Id, Iq of a rotational coordinate system are estimated from detected input d. c. current IDC flowing through the bus line of the power converter to which power is input from a d. c. power source. A output voltages of the power converterare controlled so that the estimated currents Idc, Iqc are equal to respective current instruction values Id*, Iq*. Errors of motor constants are determined from information on the motor currents and the rotational phase errors by an operation.

Apparatus for controlling an a. c. motor

In a motor driving unit controlled by switching to/from PWM control from/to PAM control so that the maximum limit of motor speed can be increased and, at the same time, the unit can be operated at maximum efficiency during steady-state operation, the motor speed is controlled by maintaining the DC voltage command to the converter control circuit constant, but altering the conduction ratio command value to the inverter control circuit when the load to the motor is low, and by maintaining the conduction ratio command to the inverter control circuit constant, but altering the DC voltage command to the converter control circuit. There is a commutating phase control circuit that alters the commutating timing of the coil of the motor, and the motor is so controlled that the efficiency reaches the maximum limit during steady-state operation and the speed reaches the maximum limit during high-speed operation.

Controller for PWM/PAM motor, air conditioner, and method of motor control

A converter module which receives an AC voltage, converts the AC voltage to a DC voltage, and outputs the DC voltage to a circuit for driving a motor. The converter module includes a switching device, a diode, and a control circuit which controls the DC voltage output by the converter module by controlling the switching device. The control circuit includes a plurality of DC voltage detection terminals which detect the DC voltage output by the converter module with respective different DC voltage detection gains, a selector which selects at least one of the DC voltage detection terminals in accordance with an external signal indicative of a speed of the motor, and outputs a DC voltage detection value, and a controller which controls the DC voltage output by the converter module in accordance with the DC voltage detection value output by the selector.

Motor controller

An air conditioner having a permanent magnet electric motor with a high output power characteristic in a cooling and heating range and a high output characteristic even in defrosting operation in a high-speed range.

Air conditioner

The present invention supplies a position detection circuit, and a motor controller, that can not only obtain rotor position detection signals properly over the entire PWM control region, but also obtain these signals properly during PAM control. In a brushless motor controller based on the present invention to detect the magnetic pole position of the stator in the motor in accordance with the stator coil terminal voltages of multiple phases and control the energization of the stator coils, the comparison result information signal, after being obtained through comparison between the detected voltage values corresponding to the foregoing terminal voltages, and a reference voltage value, is directly entered into control circuits, then the position of the rotor in the motor is properly detected immediately after power-on switching, without a rotor position detection inhibition time interval being provided, and the motor is controlled properly.

Brushless motor control device and equipment using the control device

A circuit for controlling the outdoor unit of an air conditioner comprises a microcomputer which controls two brushless motors and a microcomputer which controls the whole outdoor unit. In accordance with the present invention, separation of a function for controlling the brushless motors from a function for controlling the whole outdoor unit can simplify software for said microcomputers.

Air conditioner and brushless motor control unit

Growing community of inventors

Hitachiota, Japan

Yasuo Notohara