초록 ▼

In a motor control apparatus of the present invention, a control section which receives an input voltage to an inverter circuit, a motor current flowing to a brushless motor and a motor current command value indicating the value of a current required to flow to the inverter circuit, and controls the

In a motor control apparatus of the present invention, a control section which receives an input voltage to an inverter circuit, a motor current flowing to a brushless motor and a motor current command value indicating the value of a current required to flow to the inverter circuit, and controls the inverter circuit by maintaining a phase of the voltage applied to the brushless motor when the value of the input voltage to the inverter circuit is smaller than the value of a voltage required to be applied to the brushless motor.

대표청구항 ▼

What is claimed is: 1. A motor control apparatus comprising: an inverter circuit which receives a fluctuating voltage, converts said voltage into a desired voltage and outputs said desired voltage to a brushless motor, and a control section which receives the input voltage to said inverter circuit,

What is claimed is: 1. A motor control apparatus comprising: an inverter circuit which receives a fluctuating voltage, converts said voltage into a desired voltage and outputs said desired voltage to a brushless motor, and a control section which receives the input voltage to said inverter circuit, a motor current flowing to said brushless motor and a command value indicating the value of a current required to flow to said inverter circuit and generates sinusoidal voltage command values for controlling said inverter circuit, said control section maintaining the phase of the voltage applied to said brushless motor when the value of the input voltage to said inverter circuit is smaller than the value of a voltage required to be applied to said brushless motor. 2. A motor control apparatus in accordance with claim 1, wherein said control section estimates the rotation phase of said brushless motor on the basis of the current of said brushless motor. 3. A compressor incorporating said motor control apparatus in accordance with claim 2. 4. An air conditioner incorporating said motor control apparatus in accordance with claim 2. 5. A refrigerator incorporating said motor control apparatus in accordance with claim 2. 6. An electric washing machine incorporating said motor control apparatus in accordance with claim 2. 7. An electric dryer incorporating said motor control apparatus in accordance with claim 2. 8. A heat pump water heater incorporating said motor control apparatus in accordance with claim 2. 9. A motor control apparatus in accordance with claim 1, wherein said control section stops integral control when the voltage value across said inverter circuit is smaller than a voltage command value to be applied to said brushless motor. 10. A motor control apparatus in accordance with claim 1, wherein said control section calculates a voltage command value by using a calculation equation having a noninteracting term. 11. A motor control apparatus in accordance with claim 1, wherein said control section detects the voltage of said inverter circuit, estimates a voltage to be applied to said inverter circuit at the next control cycle and controls said inverter circuit. 12. A motor control apparatus in accordance with claim 1, incorporating a capacitor having a capacitance in said inverter circuit, wherein a capacitance of C≧10-10 and C≦2횞10-7횞P of said capacitor is established, assuming that the capacitance of said capacitor is C[F] and that the maximum output of said motor is P[W]. 13. A motor control apparatus in accordance with claim 12, incorporating an inductor having a inductance on the input side of said inverter circuit, wherein an inductance of L≧10-8 and L≦9횞10-9/C is established, assuming that the inductance of said inductor is L[H] and that the capacitance of said capacitor is C[F]. 14. A motor control apparatus in accordance with claim 13, wherein an inductance of L≧10-8 and L≦P횞10-6 established, assuming that the inductance of said inductor is L[H] and that the maximum output power of said motor is P[W]. 15. A motor control apparatus in accordance with claim 1, further comprising: a boosting circuit having an inductor, diodes, switching devices and a capacitor, and a boosting circuit control section for controlling said boosting circuit, wherein said boosting circuit control section determines the duty value of said switching device on the basis of a signal from said control section. 16. A motor control apparatus in accordance with claim 15, wherein said boosting circuit control section, which is configured to receive the detected voltage phase and AC current of an AC power source, comprises: an AC current command section that outputs an AC current command value on the basis of said detected phase and a control signal from said control section, and a PWM command generation section that generates PWM command values for driving said switching devices on the basis of said AC current command value and said detected AC current of said AC power source and outputs said PWM command values. 17. A motor control apparatus in accordance with claim 1, further comprising: a boosting circuit having an inductor to which a fluctuating voltage is input, a plurality of diodes forming a rectifying circuit, switching devices connected to said rectifying circuit and performing ON/OFF operation, and a capacitor outputting a boosted voltage, and a boosting circuit control section for controlling said boosting circuit. 18. An air conditioner incorporating said motor control apparatus in accordance with claim 1. 19. A refrigerator incorporating said motor control apparatus in accordance with claim 1. 20. An electric washing machine incorporating said motor control apparatus in accordance with claim 1. 21. An electric dryer incorporating said motor control apparatus in accordance with claim 1. 22. A blower incorporating said motor control apparatus in accordance with claim 1. 23. An electric vacuum cleaner incorporating said motor control apparatus in accordance with claim 1. 24. A heat pump water heater incorporating said motor control apparatus in accordance with claim 1.