Hitachi, Ltd.

Makoto Ishii

Yukio Kawabata

Yuhachi Takakura

Yasuo Notohara

Kazuo Tahara

Hiroshi Shinozaki

Hideyuki Nakamura

Noriaki Arakawa

Toru Inoue

Kouji Katou

Hideo Kumakura

Hideki Yoshida

Takeshi Wakatabe

Junichi Takagi

Toshio Ogawa

Tsunehiro Endo

Junichi Saeki

Kazuji Yamada

Kazuhiro Suzuki

Akihiro Tamba

Masaaki Takahashi

Hiroo Nakamura

Yasutsugu Kawaguchi

Noritaka Kamimura

Masahiro Gouda

Shoji Takaku

Motoo Morimoto

After the rotor position has been fixed prior to the start of a motor, the driving mode can be rapidly switched to sensorless driving and the motor can be started and controlled, by conducting current conversions in such a power supply pattern that increases the starting output torque of the motor, and controlling the inverter output voltage.

Starting control method of and control apparatus for synchronous motor, and air conditioner, refrigerator, washing machine and vacuum cleaner each provided with the control apparatus

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

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 refrigerator, having a motor for driving a compressor, an inverter for controlling the operation of the motor, a converter responsive to AC to perform a boosting function to supply DC of variable voltage to the inverter, converter control means for controlling the converter so that a plurality of DC voltages are outputted thereby and inverter control means for controlling the inverter in pulse width modulation each of the plurality of voltages. The lowest voltage among the plurality of voltages being a voltage which turns off the boosting function of the converter.

Refrigerator

A semiconductor device includes a main circuit part having a semiconductor device formed on an electrode plate of a lead frame and a control circuit part having protective functions, which is integrally molded by a resin mold part into an integral mold structure.

Semiconductor device including an integrally molded lead frame

When inverter control is implemented in a refrigerator or the like, the rotating speed of a compressor motor is often operated at the preset minimum rotating speed. At this time, there has been a problem that when the DC voltage is boosted, the efficiency of the circuit drops due to switching loss in the power element. Still more, when the DC voltage is boosted even at the minimum rotating speed, the lowest voltage of the DC voltage must be controlled at 163 V or more including the fluctuation of the voltage. Therefore, there has been a problem in that the efficiency of the compressor motor also drops. To avoid these problems, when the temperature within a compartment of a refrigerator is cooled and approaches a preset temperature, and when a conduction ratio of the compressor motor falls below a preset value or a command on a rotating speed of the compressor motor becomes a preset rotating speed and the actual rotating speed also becomes the preset rotating speed, the control of the converter control circuit is turned off.

A motor controller is made up of a power supply circuit rectifying an AC power supply for outputting desired DC voltages while, at the same time, improving the power factor of the AC power supply, and a motor drive circuit for driving a motor. The controller has a rectifier circuit for converting AC power to a DC voltage and a smoothing circuit, a converter circuit constituted of a chopper circuit for controlling the DC voltage by utilizing a switching operation and the energy storing effect of an inductance, a motor drive device made up of an inverter circuit connected to the output of the converter circuit to control a motor, a converter control circuit for controlling the switching operation of the chopper circuit, an inverter control circuit for controlling the switching operation of the inverter circuit thereby driving the motor, a speed detector circuit for detecting a position of the rotor of the motor for calculating the speed of the motor, a speed control circuit receiving the calculated speed value and a speed command value for controlling the motor speed through the inverter circuit, and a DC voltage control circuit receiving the output signal of the speed control circuit for controlling the DC voltage through the converter control circuit in accordance with the output signal. The DC voltage control circuit, when the output of the speed control circuit reaches a predetermined value, outputs a signal to cause the DC voltage to increase or decrease to the converter control circuit. The output of the speed control circuit is a duty ratio signal or a speed deviation signal representing a deviation of the calculated speed value from the speed command value.

A motor drive apparatus and an air-conditioner using the motor control apparatus has a feature which allows it to gradually increase a dc voltage value to a predetermined value when starting the switching operation of a chopper circuit by dc voltage control thereof, and when stopping the switching operation of the chopper circuit to be able to gradually decrease the dc voltage value to a predetermined value. Further, the dc voltage command value is adjusted so as to make it possible to maintain a preferred value of dc voltage. Thereby, fluctuation in the number of revolutions of the motor can be prevented even if the converter is started or stopped while the motor is operating, thereby allowing the motor drive apparatus and air-conditioner using the motor control apparatus of the invention to be operated at their maximum capacities.

PWM/PAM control mode switching type motor control apparatus, and motor

For achieving an air conditioner being applicable to various a-c source voltages in common and operative with high power factor by suppressing generation of high harmonics, an a-c source voltage from an a-c electric power source 1 is rectified in full-wave by a rectifier 2, and a d-c source voltage Ed of an inverter 13 is obtained by being charged in a condenser 5. Here, there are a-c source voltages of 100 V and 200 V, and a divided voltage Ed1 of the d-c voltage of the condenser 5 is selected when the a-c source voltage is 100 V, a divided voltage Ed2 (here, Ed1&gt;Ed1) of the d-c voltage of the condenser 5 is selected when the a-c source voltage is 200 V, respectively by an exchange switch 18, and is used as a d-c voltage Ed' for controlling on and off of a switch element 6. Though the d-c source voltage Ed differs depending on the a-c source voltage of 100 V or 200 V, it is possible to set the d-c source voltage Ed at a voltage value for operating the inverter 13 with low loss and high efficiency, for each one of the a-c source voltages, by setting a ratio of the voltage division appropriately.

Air conditioner

A power supply includes a rectifying section for rectifying a sinusoidal a.c. voltage, a switching section for receiving a voltage output from the rectifying section, and a smoothing section having a smoothing capacitor. The power supply is controlled to have a sinusoidal load current and includes a power source circuit having a first path for conducting current from the rectifying section to the smoothing section and a second path for conducting current from an inductor of the switching section to the smoothing section, circuits for sensing the current flowing through the first path and forming a reference current with a target waveform based on the sensed current, circuits for sensing the current flowing through the switching element and determining a conduction ratio of the switching element to match the waveform of the sensed current to the waveform of the reference current, and a control circuit for sequentially controlling a plurality of switching elements connected in parallel based on the determined conduction ratio.

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Utsunomiya, Japan

Makoto Ishii