Phase detection method, phase detecting apparatus, synchronous-motor control method, and synchronous motor controller

• US 7,839,114 B2
• Filed: 01/18/2008
• Issued: 11/23/2010
• 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:
  US12/010,021
• Publication Number:
  US 20080191657A1
• Time in Patent Office: 1,040 Days
• Field of Search: 318/701, 318/721, 318/727, 318/461, 318/800, 318/801
• US Class Current: 318/727
• 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 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 phase detection method according to claim 1, wherein at the outputting, when a starting point and an end point of the vector phase is included in the section, the vector phase value after the end point is converted to a vector phase value after the starting point.

3. The phase detection method according to claim 1, wherein at the normalizing, a value obtained by dividing a value as a result of a second subtraction, at which the subtraction result between signal amplitudes of respective phases in the section has a linear characteristic, by a value as a first subtraction result, at which the subtraction result between signal amplitudes of respective phases in the section has approximately a flat characteristic, is output as a normalized amplitude value.

4. The phase detection method according to claim 1, further comprising correcting including storing the vector phase output at the second outputting and a relationship of phase difference between the vector phase and a real vector phase, and correcting the vector phase by addition or subtraction of the phase difference to/from the vector phase based on the relationship.

5. A 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.

6. The phase detection method according to claim 5, further comprising correcting including storing the vector phase output at the second outputting and a relationship of phase difference between the vector phase and a real vector phase, and correcting the vector phase by addition or subtraction of the phase difference to/from the vector phase based on the relationship.

7. A 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.

8. The phase detecting apparatus according to claim 7, wherein, when a starting point and an end point of the vector phase is included in the section, the phase outputting unit converts the vector phase value after the end point to a vector phase value after the starting point.

9. The phase detecting apparatus according to claim 7, wherein the amplitude normalizing unit outputs a value obtained by dividing a value as a result of a second subtraction, at which the subtraction result between signal amplitudes of respective phases in the section has a linear characteristic, by a value as a first subtraction result, at which the subtraction result between signal amplitudes of respective phases in the section has approximately a flat characteristic, as a normalized amplitude value.

10. The phase detecting apparatus according to claim 7, further comprising a correcting unit that stores the vector phase output by the phase outputting unit and a relationship of phase difference between the vector phase and a real vector phase, and corrects the vector phase by addition or subtraction of the phase difference to/from the vector phase based on the relationship.

11. A 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.

12. The phase detecting apparatus according to claim 11, further comprising a correcting unit that stores the vector phase output by the phase outputting unit and a relationship of phase difference between the vector phase and a real vector phase, and corrects the vector phase by addition or subtraction of the phase difference to/from the vector phase based on the relationship.