Abstract: A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.

Abstract: In detecting an output current of a power converter based on a DC current Idc of the power converter, the pulse width of the DC current Idc becomes narrower when the pulse width of a line voltage is narrower, and its detection becomes difficult. A voltage command correction unit 9 according to the present invention corrects voltage commands such that pulse width of a line voltage becomes zero when the pulse width of the line voltage is less than the minimum pulse width, not to output a line pulse, and an error generated by the correction is integrated. This integrated error is added to the line voltage in the next time, and the integrated pulse width of the line voltage is outputted when the pulse width becomes larger than or equal to the minimum pulse width.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: 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.

Abstract: 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.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: 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.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.

Abstract: 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.

Abstract: 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.

Abstract: In detecting an output current of a power converter based on a DC current Idc of the power converter, the pulse width of the DC current Idc becomes narrower when the pulse width of a line voltage is narrower, and its detection becomes difficult. A voltage command correction unit 9 according to the present invention corrects voltage commands such that pulse width of a line voltage becomes zero when the pulse width of the line voltage is less than the minimum pulse width, not to output a line pulse, and an error generated by the correction is integrated. This integrated error is added to the line voltage in the next time, and the integrated pulse width of the line voltage is outputted when the pulse width becomes larger than or equal to the minimum pulse width.

Abstract: An inverter air conditioner for controlling room temperature to a predetermined temperature by controlling the number of revolutions of a compressor and controlling variables of the refrigerating cycle including the opening degree of an expansion valve and the air quantity of a heat exchanger. The inverter air conditioner detects a number-of-revolution command value for the compressor and changes controlled variables of the refrigerating cycle, such as the opening degree of the expansion valve and the air quantity of the heat exchanger, in accordance with the number-of-revolution command value thereby, achieving room temperature control.

Abstract: 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.

Abstract: 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.

Abstract: 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>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.

Abstract: An inverter apparatus includes a flip-flop circuit and a voltage clamp circuit disposed in the upper arm, and set and reset signal generators each having a series connection of two switching devices. By using an input signal and using an output signal of the flip-flop circuit, the above described two switching devices are activated in a complementary manner. Owing to this configuration, no current flows except a minute time for supplying a trigger signal to the flip-flop circuit, resulting in low current consumption. If the output logic of the flip-flop circuit has been inverted by noise, two switching devices are simultaneously in the on-state and a re-trigger current is let flow to restore the above described output logic to the normal state, resulting in the complementary state again. As a result, signal transmission between the upper and lower arms is performed at higher speed and with a lower loss. In addition, the inverter apparatus is protected from false operation due to noise.