Synchronous motor control method

• US 8,319,459 B2
• Filed: 11/05/2010
• Issued: 11/27/2012
• Est. Priority Date: 02/08/2007
• Status: Active Grant

• Current Assignee: Fujitsu General Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fujitsu General Company Limited (Fujifilm Holdings Corporation)
• Inventors: Ichiki, Satoshi, Kawaguchi, Naoki
• Primary Examiner(s): DUDA, RINA I
• Application Number:
  US12/940,663
• Publication Number:
  US 20110050139A1
• Time in Patent Office: 753 Days
• Field of Search: 318/727, 318/729, 318/700, 318/400.02
• US Class Current: 318/400.02
• CPC Class Codes: G01R 21/06 by measuring current and voltage G01R21/08 - G01R21/133 take precedence
• CPC Class Codes: G01R 25/00 Arrangements for measuring phase angle between a voltage and a current or between voltages or currents
• CPC Class Codes: H02P 23/26 Power factor control [PFC]
• CPC Class Codes: H02P 25/024 controlled by supply frequency

Abstract

It is determined which of six continuous sections having different magnitude correlation of signal amplitude of each phase of an input three-phase signal a section is. Predetermined subtraction is performed between respective phases in the section, to obtain a normalized amplitude value normalized in the section, using the subtraction result. The normalized amplitude value is converted to a vector phase for one cycle based on a predetermined phase and output corresponding to the determined section.

Claims

1. A synchronous-motor control method comprising:

calculating a voltage vector phase and a current vector phase to be applied to the synchronous motor based on a phase detection method to calculate a power factor, which is a phase difference between the voltage vector phase and the current vector phase on a real time basis; and

controlling the synchronous motor based on the power factor, wherein

the phase detection method comprising;

determining which of a plurality of continuous sections having different magnitude correlation of signal amplitude of each phase a section is, based on an input signal amplitude value of a plurality of phases;

normalizing including performing predetermined subtraction with respect to the signal amplitude between respective phases for each section determined at the determining, to obtain a normalized amplitude value normalized in the section, using the subtraction result; and

outputting including converting the normalized amplitude value obtained at the normalizing to a vector phase for one cycle based on a predetermined phase, and outputting the vector phase corresponding to the section determined at the determining.

2. The synchronous-motor control method according to claim 1, further comprising feedback controlling including providing a target value of the power factor and performing feedback control so that the power factor is approximated to the target value.

3. The synchronous-motor control method according to claim 2, wherein at the feedback controlling, amplitude adjustment is performed with respect to the voltage amplitude value to be applied to the synchronous motor to approximate the power factor to the target value.

4. The synchronous-motor control method according to claim 2, wherein at the feedback controlling, amplitude adjustment is performed for reducing an error between the power factor and the target value, to approximate the power factor to the target value.

5. The synchronous-motor control method according to claim 2, wherein at the feedback controlling, a gain of at least one of amplitude adjustment or phase adjustment is changed according to a torque of the synchronous motor obtained based on the voltage value of each phase and the current value of each phase.

6. The synchronous-motor control method according to claim 2, wherein the feedback controlling further includes target-power-factor converting including outputting a target value of the power factor corresponding to the voltage value and the current value of each phase based on a relationship between the torque obtained based on the voltage value and the current value of each phase and a power factor having high power consumption efficiency, wherein the feedback controlling is performed to approximate the power factor to the target value, using the target value.

7. The synchronous-motor control method according to claim 6, wherein at the target-power-factor converting, the voltage value and the current value of each phase are feedback controlled to output a target value of the power factor having the high power consumption efficiency with respect to the torque.

8. The synchronous-motor control method according to claim 1, wherein at the power-factor calculating, the voltage vector phase to be applied to the synchronous motor is detected based on a drive control signal to be applied to the synchronous motor.

9. A synchronous-motor control method comprising:

calculating a voltage vector phase and a current vector phase to be applied to the synchronous motor based on a phase detection method to calculate a power factor, which is a phase difference between the voltage vector phase and the current vector phase on a real time basis; and

controlling the synchronous motor based on the power factor, wherein

the phase detection method comprising;

determining which of six continuous sections, first to sixth sections, in which magnitude correlation of a signal amplitude value of an input three-phase signal of R-phase, S-phase, and T-phase takes a R-phase value>

T-phase value>

S-phase value, a R-phase value>

S-phase value>

T-phase value, a S-phase value>

R-phase value>

T-phase value, a S-phase value>

T-phase value>

R-phase value, a T-phase value>

S-phase value>

R-phase value, and a T-phase value>

R-phase value>

S-phase value, the section is;

calculating the first section by ((R-phase value)−

(T-phase value))/((R-phase value)−

(S-phase value)), the second section by ((S-phase value)−

(T-phase value))/((R-phase value)−

(T-phase value)), the third section by ((S-phase value)−

(R-phase value))/((S-phase value)−

(T-phase value)), the fourth section by ((T-phase value)−

(R-phase value))/((S-phase value)−

(R-phase value)), the fifth section by ((T-phase value)−

(S-phase value))/((T-phase value)−

(R-phase value)), the sixth section by ((R-phase value)−

(S-phase value))/((T-phase value)−

(S-phase value)), to obtain a normalized amplitude value normalized in each section; and

second outputting including multiplying the normalized amplitude value of the first to the sixth sections, respectively, by a phase of 60°

, to calculate a phase value by adding phases of 30°

, 90°

, 150°

, 210°

, 270°

, and 330°

, respectively, to the multiplied values of the first to the sixth sections, and when the phase value of the sixth section is equal to or larger than 360°

, obtaining a phase value by subtracting the phase of 360°

from the phase value, and outputting a vector phase for one cycle.

10. The synchronous-motor control method according to claim 9, further comprising feedback controlling including providing a target value of the power factor and performing feedback control so that the power factor is approximated to the target value.

11. The synchronous-motor control method according to claim 10, wherein at the feedback controlling, amplitude adjustment is performed with respect to the voltage amplitude value to be applied to the synchronous motor to approximate the power factor to the target value.

12. The synchronous-motor control method according to claim 10, wherein at the feedback controlling, amplitude adjustment is performed for reducing an error between the power factor and the target value, to approximate the power factor to the target value.

13. The synchronous-motor control method according to claim 10, wherein at the feedback controlling, a gain of at least one of amplitude adjustment or phase adjustment is changed according to a torque of the synchronous motor obtained based on the voltage value of each phase and the current value of each phase.

14. The synchronous-motor control method according to claim 10, wherein the feedback controlling further includes target-power-factor converting including outputting a target value of the power factor corresponding to the voltage value and the current value of each phase based on a relationship between the torque obtained based on the voltage value and the current value of each phase and a power factor having high power consumption efficiency, wherein the feedback controlling is performed to approximate the power factor to the target value, using the target value.

15. The synchronous-motor control method according to claim 14, wherein at the target-power-factor converting, the voltage value and the current value of each phase are feedback controlled to output a target value of the power factor having the high power consumption efficiency with respect to the torque.

16. The synchronous-motor control method according to claim 9, wherein at the power-factor calculating, the voltage vector phase to be applied to the synchronous motor is detected based on a drive control signal to be applied to the synchronous motor.

17. A synchronous motor controller comprising:

a voltage phase detector that acquires a vector phase of voltage to be applied to a synchronous motor by a phase detecting apparatus;

a current phase detector that obtains a vector phase of current to be applied to the synchronous motor by the phase detecting apparatus;

a power factor calculator that calculates a power factor, which is a phase difference between the voltage vector phase detected by the voltage phase detector and the current vector phase detected by the current phase detector, on a real time basis; and

a control unit that performs synchronous control on the synchronous motor based on the power factor obtained by the power factor calculator, wherein

the phase detecting apparatus comprising;

a section determining unit that determines which of a plurality of continuous sections having different magnitude correlation of signal amplitude of each phase a section is, based on an input signal amplitude value of a plurality of phases;

an amplitude normalizing unit that performs predetermined subtraction with respect to the signal amplitude between respective phases for each section determined by the section determining unit, to obtain a normalized amplitude value normalized in the section, using the subtraction result; and

a phase outputting unit that converts the normalized amplitude value obtained by the amplitude normalizing unit to a vector phase for one cycle based on a predetermined phase, and outputs the vector phase corresponding to the section determined by the section determining unit.

18. The synchronous motor controller according to claim 17, further comprising a target-power-factor setting unit that sets a target value of the power factor, wherein

the control unit performs feedback control to approximate the power factor obtained by the power factor calculator to the target value set by the target-power-factor setting unit.

19. The synchronous motor controller according to claim 18, wherein the control unit performs amplitude adjustment with respect to a voltage amplitude value to be applied to the synchronous motor to approximate the power factor to the target value.

20. The synchronous motor controller according to claim 18, wherein the control unit performs phase adjustment for reducing an error between the power factor calculated by the power factor calculator and the target value, to approximate the power factor to the target value.

21. The synchronous motor controller according to claim 18, wherein the control unit changes a gain of at least amplitude adjustment or phase adjustment is changed according to a torque of the synchronous motor obtained based on the voltage value of each phase and the current value of each phase.

22. The synchronous motor controller according to claim 17, further comprising a target-power-factor converter that outputs a target value of a power factor corresponding to the voltage value and the current value of each phase based on a relationship between the torque obtained based on the voltage value and the current value of each phase and a power factor having high power consumption efficiency with the torque, wherein

the target-power-factor setting unit sets the power factor to the one output from the target-power-factor converter.

23. The synchronous motor controller according to claim 22, wherein the target-power-factor converter feeds back the voltage value and the current value of each phase to output a target value of the power factor.

24. A synchronous motor controller comprising:

a current phase detector that acquires a vector phase of current to be applied to the synchronous motor by a phase detecting apparatus;

a power factor calculator that calculates a power factor, which is a phase difference between a voltage vector phase and the current vector phase detected by the current phase detector, on a real time basis; and

a control unit that performs synchronous control with respect to the synchronous motor based on the power factor obtained by the power factor calculator, wherein

the voltage vector phase to be input to the power factor calculator is controlled by the control unit, so that the phase is a phase of a voltage drive signal for generating an AC signal to be applied to the synchronous motor, wherein

the phase detecting apparatus comprising;

a section determining unit that determines which of a plurality of continuous sections having different magnitude correlation of signal amplitude of each phase a section is, based on an input signal amplitude value of a plurality of phases;

an amplitude normalizing unit that performs predetermined subtraction with respect to the signal amplitude between respective phases for each section determined by the section determining unit, to obtain a normalized amplitude value normalized in the section, using the subtraction result; and

a phase outputting unit that converts the normalized amplitude value obtained by the amplitude normalizing unit to a vector phase for one cycle based on a predetermined phase, and outputs the vector phase corresponding to the section determined by the section determining unit.

25. A synchronous motor controller comprising:

a voltage phase detector that acquires a vector phase of voltage to be applied to a synchronous motor by a phase detecting apparatus;

a current phase detector that obtains a vector phase of current to be applied to the synchronous motor by the phase detecting apparatus;

a power factor calculator that calculates a power factor, which is a phase difference between the voltage vector phase detected by the voltage phase detector and the current vector phase detected by the current phase detector, on a real time basis; and

a control unit that performs synchronous control on the synchronous motor based on the power factor obtained by the power factor calculator, wherein

the phase detecting apparatus comprising;

a section determining unit that determines which of six continuous sections, first to sixth sections, in which magnitude correlation of a signal amplitude value of an input three-phase signal of R-phase, S-phase, and T-phase takes a R-phase value>

T-phase value>

S-phase value, a R-phase value>

S-phase value>

T-phase value, a S-phase value>

R-phase value>

T-phase value, a S-phase value>

T-phase value>

R-phase value, a T-phase value>

S-phase value>

R-phase value, and a T-phase value>

R-phase value>

S-phase value, the section is;

an amplitude normalizing unit that calculates the first section by ((R-phase value)−

(T-phase value))/((R-phase value)−

(S-phase value)), the second section by ((S-phase value)−

(T-phase value))/((R-phase value)−

(T-phase value)), the third section by ((S-phase value)−

(R-phase value))/((S-phase value)−

(T-phase value)), the fourth section by ((T-phase value)−

(R-phase value))/((S-phase value)−

(R-phase value)), the fifth section by ((T-phase value)−

(S-phase value))/((T-phase value)−

(R-phase value)), the sixth section by ((R-phase value)−

(S-phase value))/((T-phase value)−

(S-phase value)), to obtain a normalized amplitude value normalized in each section; and

a phase outputting unit that multiplies the normalized amplitude value of the first to the sixth sections, respectively, by a phase of 60°

, to calculate a phase value by adding phases of 30°

, 90°

, 150°

, 210°

, 270°

, and 330°

, respectively, to the multiplied values of the first to the sixth sections, and when the phase value of the sixth section is equal to or larger than 360°

, obtains a phase value by subtracting the phase of 360°

from the phase value, and outputs a vector phase for one cycle.

26. The synchronous motor controller according to claim 25, further comprising a target-power-factor setting unit that sets a target value of the power factor, wherein

the control unit performs feedback control to approximate the power factor obtained by the power factor calculator to the target value set by the target-power-factor setting unit.

27. The synchronous motor controller according to claim 26, wherein the control unit performs amplitude adjustment with respect to a voltage amplitude value to be applied to the synchronous motor to approximate the power factor to the target value.

28. The synchronous motor controller according to claim 26, wherein the control unit performs phase adjustment for reducing an error between the power factor calculated by the power factor calculator and the target value, to approximate the power factor to the target value.

29. The synchronous motor controller according to claim 26, wherein the control unit changes a gain of at least amplitude adjustment or phase adjustment is changed according to a torque of the synchronous motor obtained based on the voltage value of each phase and the current value of each phase.

30. The synchronous motor controller according to claim 25, further comprising a target-power-factor converter that outputs a target value of a power factor corresponding to the voltage value and the current value of each phase based on a relationship between the torque obtained based on the voltage value and the current value of each phase and a power factor having high power consumption efficiency with the torque, wherein

the target-power-factor setting unit sets the power factor to the one output from the target-power-factor converter.

31. The synchronous motor controller according to claim 30, wherein the target-power-factor converter feeds back the voltage value and the current value of each phase to output a target value of the power factor.

32. A synchronous motor controller comprising:

a current phase detector that acquires a vector phase of current to be applied to the synchronous motor by a phase detecting apparatus;

a power factor calculator that calculates a power factor, which is a phase difference between a voltage vector phase and the current vector phase detected by the current phase detector, on a real time basis; and

a control unit that performs synchronous control with respect to the synchronous motor based on the power factor obtained by the power factor calculator, wherein

the voltage vector phase to be input to the power factor calculator is controlled by the control unit, so that the phase is a phase of a voltage drive signal for generating an AC signal to be applied to the synchronous motor, wherein

the phase detecting apparatus comprising;

a section determining unit that determines which of six continuous sections, first to sixth sections, in which magnitude correlation of a signal amplitude value of an input three-phase signal of R-phase, S-phase, and T-phase takes a R-phase value>

T-phase value>

S-phase value, a R-phase value>

S-phase value>

T-phase value, a S-phase value>

R-phase value>

T-phase value, a S-phase value>

T-phase value>

R-phase value, a T-phase value>

S-phase value>

R-phase value, and a T-phase value>

R-phase value>

S-phase value, the section is;

an amplitude normalizing unit that calculates the first section by ((R-phase value)−

(T-phase value))/((R-phase value)−

(S-phase value)), the second section by ((S-phase value)−

(T-phase value))/((R-phase value)−

(T-phase value)), the third section by ((S-phase value)−

(R-phase value))/((S-phase value)−

(T-phase value)), the fourth section by ((T-phase value)−

(R-phase value))/((S-phase value)−

(R-phase value)), the fifth section by ((T-phase value)−

(S-phase value))/((T-phase value)−

(R-phase value)), the sixth section by ((R-phase value)−

(S-phase value))/((T-phase value)−

(S-phase value)), to obtain a normalized amplitude value normalized in each section; and

a phase outputting unit that multiplies the normalized amplitude value of the first to the sixth sections, respectively, by a phase of 60°

, to calculate a phase value by adding phases of 30°

, 90°

, 150°

, 210°

, 270°

, and 330°

, respectively, to the multiplied values of the first to the sixth sections, and when the phase value of the sixth section is equal to or larger than 360°

, obtains a phase value by subtracting the phase of 360°

from the phase value, and outputs a vector phase for one cycle.