US5739650A
Expired / Lapsed
US
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Motor system capable of obtaining high efficiency and method for controlling a motor
Assignee: Daikin Industries Ltd
•
Filing: 1995-07-24
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Granted: 1998-04-14
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Expires: 2015-07-24
Abstract
Abstract PCT No. PCT/JP95/01468 Sec. 371 Date Mar. 25, 1996 Sec. 102(e) Date Mar. 25, 1996 PCT Filed Jul. 24, 1995 PCT Pub. No. WO96/03797 PCT Pub. Date Feb. 8, 1996In a brushless DC motor system, an RMS value of an input current of a voltage-fed inverter (702) is detected by a current transformer (705) and an RMS value detector circuit (706). A rotation speed of a brushless DC motor (703) is detected based on a cycle of a position signal outputted by a position sensor circuit (704). Then, in response to the RMS value of the input current and the rotation speed, the phase of the inverter output voltage relative to the phase of the motor counter-electromotive voltage is set to a phase at which the motor efficiency comes generally to a peak, and a switching command to the voltage-fed inverter (702) is generated. With this constitution, when the applied voltage waveform is controlled only by the voltage-fed inverter in response to the rotor-position detection signal, the motor attains high-efficiency operation without involving any increase in cost and yet regardless of load conditions.
Inventors
- 👤 Taizou Kimura
- 👤 Kiyotaka Nishijima
- 👤 Hiroyuki Yamai
- 👤 Akio Yamagiwa
- 👤 Kazunobu Ooyama
- 👤 Nobuki Kitano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:24
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/08; H02P6/14; H02P6/16; H02P6/18; H02P6/187; H02P6/085; H02P6/17; H02P2209/00; H02P2209/07
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
92 words
A method for controlling a brushless DC motor comprising the steps of: detecting a rotation speed and a rotor position of a brushless DC motor driven by a voltage-fed inverter; detecting an input current of the voltage-fed inverter; and setting a switching command to the voltage-fed inverter such that the phase of the inverter output voltage relative to the phase of the motor counter-electromotive voltage is set to a specified phase at which motor efficiency comes generally to a peak, in response to the detected rotation speed and the detected input current.
Claim 2
Independent Claim
92 words
A method for controlling a brushless DC motor comprising the steps of: detecting a rotation speed and a rotor position of a brushless DC motor driven by a voltage-fed inverter; detecting an input current of the voltage-fed inverter; and setting a switching command to the voltage-fed inverter such that the phase of the inverter output voltage relative to the phase of the motor counter-electromotive voltage is set to a specified phase at which motor efficiency comes generally to a peak, in response to the detected rotation speed and the detected input current.
Claim 3
Dependent Claim
42 words
The method for controlling a brushless DC motor according to claim 1, wherein the phase at which motor efficiency comes generally to a peak leads, by a specified value, a phase at which the brushless DC motor is driven at peak efficiency.
Claim 4
Dependent Claim
96 words
A brushless DC motor system comprising: a rotational-position sensor for detecting a rotation speed and a rotor position of a brushless DC motor driven by a voltage-fed inverter; detection means for detecting an input current of the voltage-fed inverter; and inverter control means for setting a switching command to the voltage-fed inverter such that a phase of an inverter output voltage relative to a phase of a motor counter-electromotive voltage is set to a phase at which motor efficiency comes generally to a peak, in response to the detected rotation speed and the detected input current.
Claim 5
Dependent Claim
96 words
A brushless DC motor system comprising: a rotational-position sensor for detecting a rotation speed and a rotor position of a brushless DC motor driven by a voltage-fed inverter; detection means for detecting an input current of the voltage-fed inverter; and inverter control means for setting a switching command to the voltage-fed inverter such that a phase of an inverter output voltage relative to a phase of a motor counter-electromotive voltage is set to a phase at which motor efficiency comes generally to a peak, in response to the detected rotation speed and the detected input current.
Claim 6
Dependent Claim
96 words
The brushless DC motor system according to claim 3, wherein said inverter control means includes phase holding means for holding a phase at which a peak motor efficiency can be obtained with the rotation speed and the input current, the phase having been obtained from previously performed measurements, and wherein said inverter control means sets a switching command to the voltage-fed inverter by reading a corresponding phase from said phase holding means as the phase at which motor efficiency comes generally to a peak, in response to the detected rotation speed and the detected input current.
Claim 7
Dependent Claim
141 words
The brushless DC motor system according to claim 3, wherein said inverter control means further includes: value holding means for holding values that prescribe a variation characteristic of a phase at which a peak motor efficiency can be obtained with the rotation speed and the input current, the values having been obtained from previously performed measurements, and linear approximation means for linearly approximating a phase based on a value held in said value holding means, and wherein said inverter control means reads a corresponding value from said value holding means in response to a detected rotation speed and a detected input current, obtains a phase through a linear approximation with said linear approximation means, and sets a switching command to the voltage-fed inverter with the obtained phase taken as the phase at which the motor efficiency comes generally to a peak.
Claim 8
Dependent Claim
45 words
The brushless DC motor system according to claim 3, wherein said inverter control means further includes phase correction means for setting a switching command to the voltage-fed inverter by advancing, by a specified value, the phase at which the motor efficiency comes to a peak.
Claim 9
Independent Claim
124 words
A method for controlling a brushless DC motor comprising the steps of: detecting a rotation speed and a rotor position of a brushless DC motor driven by a voltage-fed inverter; setting an output voltage amplitude of the voltage-fed inverter to a specified amplitude that is determined based on the detected rotation speed; and setting, in response to a difference between a rotation speed command to the brushless DC motor and the detected rotation speed, a switching command to the voltage-fed inverter such that a phase of an inverter output voltage relative to a phase of a motor counter-electromotive voltage is set to a specified phase, and such that a terminal voltage conduction width of the voltage-fed inverter is set to 180° in electrical angle.
Claim 10
Independent Claim
124 words
A method for controlling a brushless DC motor comprising the steps of: detecting a rotation speed and a rotor position of a brushless DC motor driven by a voltage-fed inverter; setting an output voltage amplitude of the voltage-fed inverter to a specified amplitude that is determined based on the detected rotation speed; and setting, in response to a difference between a rotation speed command to the brushless DC motor and the detected rotation speed, a switching command to the voltage-fed inverter such that a phase of an inverter output voltage relative to a phase of a motor counter-electromotive voltage is set to a specified phase, and such that a terminal voltage conduction width of the voltage-fed inverter is set to 180° in electrical angle.
Claim 11
Dependent Claim
23 words
The method according to claim 7, wherein the rotor of the brushless DC motor is a rotor having a permanent magnet disposed inside.
Claim 12
Dependent Claim
99 words
The method for controlling a brushless DC motor according to claim 7 further comprising the steps of: obtaining a first neutral-point voltage by connecting resistors, which are respectively connected at one end to output terminals of individual phases of the voltage-fed inverter, to one another at the other end; obtaining a second neutral-point voltage by connecting stator windings of individual phases of the brushless DC motor to one another at one end; and detecting a magnetic-pole position of the rotor of the brushless DC motor based on a difference between the first neutral-point voltage and the second neutral-point voltage.
Claim 13
Dependent Claim
128 words
A brushless DC motor system comprising: a rotational-position sensor for detecting a rotation speed and rotor position of a brushless DC motor driven by a voltage-fed inverter; inverter control means for setting an output voltage amplitude of the voltage-fed inverter to a specified amplitude that is determined based on the detected rotation speed; and setting means for setting, in response to a difference between a rotation speed command to the brushless DC motor and the detected rotation speed, a switching command to the voltage-fed inverter such that a phase of an inverter output voltage relative to a phase of a motor counter-electromotive voltage is set to a specified phase and, such that a terminal voltage conduction width of the voltage-fed inverter is set to 180° in electrical angle.
Claim 14
Dependent Claim
128 words
A brushless DC motor system comprising: a rotational-position sensor for detecting a rotation speed and rotor position of a brushless DC motor driven by a voltage-fed inverter; inverter control means for setting an output voltage amplitude of the voltage-fed inverter to a specified amplitude that is determined based on the detected rotation speed; and setting means for setting, in response to a difference between a rotation speed command to the brushless DC motor and the detected rotation speed, a switching command to the voltage-fed inverter such that a phase of an inverter output voltage relative to a phase of a motor counter-electromotive voltage is set to a specified phase and, such that a terminal voltage conduction width of the voltage-fed inverter is set to 180° in electrical angle.
Claim 15
Dependent Claim
25 words
The brushless motor system according to claim 10, wherein the rotor of the brushless DC motor is a rotor having a permanent magnet disposed inside.
Claim 16
Dependent Claim
124 words
The brushless DC motor system according to claim 10, further comprising: resistors which are connected at one end to respective output terminals of individuals phases of the voltage-fed inverter, and are connected at the other end to one another; and difference-voltage output means for receiving, as inputs, a first neutral-point voltage obtained at the other ends of said resistors and a second neutral-point voltage obtained at one end of stator windings of individual phases of the brushless DC motor at which the stator windings are connected to one another, and for delivering, as an output, a difference voltage between the two neutral-point voltages, wherein said position sensor detects a magnetic-pole position of the rotor of the brushless DC motor based on the difference voltage.
Claim 17
Dependent Claim
22 words
The brushless DC motor system according to claim 10, wherein said motor is adopted as a drive source for an electrical appliance.
Claim 18
Dependent Claim
105 words
A motor system comprising: a rotor; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in three-phase star configuration in parallel to said armature coils; an inverter for switching a voltage pattern to be applied to said armature coils; and control means for controlling an output of said inverter so that a specified efficiency is obtained, based on a neutral-point voltage of said armature coils, said control means including a level decision means for determining a relationship between a signal representing a voltage difference between neutral points of said armature coils and said resistor circuit and a target value.
Claim 19
Dependent Claim
105 words
A motor system comprising: a rotor; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in three-phase star configuration in parallel to said armature coils; an inverter for switching a voltage pattern to be applied to said armature coils; and control means for controlling an output of said inverter so that a specified efficiency is obtained, based on a neutral-point voltage of said armature coils, said control means including a level decision means for determining a relationship between a signal representing a voltage difference between neutral points of said armature coils and said resistor circuit and a target value.
Claim 20
Dependent Claim
15 words
The motor system according to claim 14, wherein the specified efficiency is a peak efficiency.
Claim 21
Dependent Claim
78 words
The motor system according to claim 14, further comprising: rotor-position sensor means for detecting a relative rotor position between said rotor and said stator, and thereby outputting a position signal, wherein said control means further includes phase correction means for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 22
Dependent Claim
78 words
The motor system according to claim 15, further comprising: rotor-position sensor means for detecting a relative rotor position between said rotor and said stator, and thereby outputting a position signal, wherein said control means further includes; phase correction means for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 23
Dependent Claim
99 words
The motor system according to claim 14, wherein said level decision means determines a relationship between a level of an integral signal derived by integrating the signal representing the voltage difference between the neutral point of said armature coils and the neutral point of said resistor circuit and the target value and said control means further including phase correction means (T1,T2,41,42) for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the integral signal becomes the target value, based on a decision result of the level decision means.
Claim 24
Dependent Claim
106 words
The motor system according to claim 15, wherein said level decision means determines a relationship between a level of an integral signal derived by integrating the signal representing the voltage difference between the neutral point of said armature coils and the neutral point of said resistor circuit and the target value at which a peak efficiency is obtained and said control means further including phase correction means (T1,T2,41,42) for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the integral signal becomes the target value, based on a decision result of the level decision means.
Claim 25
Dependent Claim
47 words
The motor system according to claim 14, wherein said control means further includes voltage correction means for correcting an output voltage of said inverter so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 26
Dependent Claim
47 words
The motor system according to claim 15, wherein said control means further includes voltage correction means for correcting an output voltage of said inverter so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 27
Dependent Claim
84 words
The motor system according to claim 20, wherein said level decision means determines a relationship between an integral signal derived by integrating the signal representing the voltage difference between the neutral point of said armature coils and the neutral point of said resistor circuit and the target value and said voltage correction means corrects an output voltage of the inverter (20, 320) so that the level of the integral signal becomes the target value, based on a decision result of the level decision means.
Claim 28
Dependent Claim
91 words
The motor system according to claim 21, wherein said level decision means determines a relationship between an integral signal derived by integrating the signal representing the voltage difference between the neutral point of said armature coils and the neutral point of said resistor circuit and the target value at which a peak efficiency is obtained and said voltage correction means corrects an output voltage of the inverter (20, 320) so that the level of the integral signal becomes the target value, based on a decision result of the level decision means.
Claim 29
Dependent Claim
211 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; rotational-position sensor means for detecting a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit, detecting a relative rotational position between said rotor and said stator based on the voltage difference signal, and outputting a position signal; an inverter for switching over a voltage pattern to be applied to said armature coils based on the position signal output by said rotational-position sensor means; integration means for integrating the voltage difference signal detected by said rotational position sensor means and outputting an integral signal; level decision means for, upon receiving the integral signal from said integration means, deciding a relationship between a level of the integral signal and a target value; and phase correction means for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the integral signal derived from said integration means becomes the target value, based on a decision result of said level decision means.
Claim 30
Dependent Claim
211 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; rotational-position sensor means for detecting a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit, detecting a relative rotational position between said rotor and said stator based on the voltage difference signal, and outputting a position signal; an inverter for switching over a voltage pattern to be applied to said armature coils based on the position signal output by said rotational-position sensor means; integration means for integrating the voltage difference signal detected by said rotational position sensor means and outputting an integral signal; level decision means for, upon receiving the integral signal from said integration means, deciding a relationship between a level of the integral signal and a target value; and phase correction means for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the integral signal derived from said integration means becomes the target value, based on a decision result of said level decision means.
Claim 31
Dependent Claim
32 words
The motor system according to claim 24, wherein the target value of said level decision means is set to a level of the integral signal at which a peak efficiency is obtained.
Claim 32
Dependent Claim
152 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; an inverter for outputting a voltage to be applied to said armature coils; integration means for integrating a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit, and outputting an integral signal; level decision means for, upon receiving the integral signal from said integration means, deciding a relationship between a level of the integral signal and a target value; and voltage correction means for correcting an output voltage of said inverter so that the level of the integral signal derived from said integration means becomes the target value, based on a decision result of said level decision means.
Claim 33
Dependent Claim
152 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; an inverter for outputting a voltage to be applied to said armature coils; integration means for integrating a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit, and outputting an integral signal; level decision means for, upon receiving the integral signal from said integration means, deciding a relationship between a level of the integral signal and a target value; and voltage correction means for correcting an output voltage of said inverter so that the level of the integral signal derived from said integration means becomes the target value, based on a decision result of said level decision means.
Claim 34
Dependent Claim
32 words
The motor system according to claim 26, wherein the target value of said level decision means is set to a level of the integral signal at which a peak efficiency is obtained.
Claim 35
Dependent Claim
190 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; rotational-position sensor means for detecting a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit, detecting a relative rotational position between said rotor and said stator based on the voltage difference signal, and outputting a position signal; an inverter for switching over a voltage pattern to be applied to said armature coils, based on the position signal of said rotational-position sensor means; level decision means for, upon receiving the voltage difference signal detected by said rotational-position sensor means, deciding a relationship between a level of the voltage difference signal and a target value; and phase correction means for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 36
Dependent Claim
190 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; rotational-position sensor means for detecting a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit, detecting a relative rotational position between said rotor and said stator based on the voltage difference signal, and outputting a position signal; an inverter for switching over a voltage pattern to be applied to said armature coils, based on the position signal of said rotational-position sensor means; level decision means for, upon receiving the voltage difference signal detected by said rotational-position sensor means, deciding a relationship between a level of the voltage difference signal and a target value; and phase correction means for adjusting a time interval from the position signal to a switching of the voltage pattern so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 37
Dependent Claim
33 words
The motor system according to claim 28, wherein the target value of said level decision means is set to a level of the voltage difference signal at which a peak efficiency is obtained.
Claim 38
Dependent Claim
127 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; an inverter for outputting a voltage to be applied to said armature coils; level decision means for deciding a relationship between a level of a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit and a target value; and voltage correction means for correcting an output voltage of said inverter so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 39
Dependent Claim
127 words
A motor system comprising: a rotor having a magnet with a plurality of poles; a stator having armature coils connected in a three-phase star configuration; a resistor circuit connected in a three-phase star configuration in parallel to said armature coils; an inverter for outputting a voltage to be applied to said armature coils; level decision means for deciding a relationship between a level of a voltage difference signal representing a voltage difference between a neutral point of said armature coils and a neutral point of said resistor circuit and a target value; and voltage correction means for correcting an output voltage of said inverter so that the level of the voltage difference signal becomes the target value, based on a decision result of said level decision means.
Claim 40
Dependent Claim
33 words
The motor system according to claim 30, wherein the target value of said level decision means is set to a level of the voltage difference signal at which a peak efficiency is obtained.
Claim 41
Independent Claim
126 words
A method for controlling a motor which includes a stator having armature coils connected in a three-phase star configuration, a resistor circuit connected in a three-phase star configuration in parallel with the armature coils, and an inverter for switching a voltage pattern applied to the armature coils, said method comprising the steps of: calculating a voltage difference between a neutral point of the armature coils and a neutral point of the resistor circuit; determining a relationship between a signal representing the voltage difference obtained in said calculating step and a target value; and controlling an output of the inverter so that a specified efficiency is obtained based on the relationship between the signal representing the voltage difference and the target value determined by said determining step.
Claim 42
Independent Claim
126 words
A method for controlling a motor which includes a stator having armature coils connected in a three-phase star configuration, a resistor circuit connected in a three-phase star configuration in parallel with the armature coils, and an inverter for switching a voltage pattern applied to the armature coils, said method comprising the steps of: calculating a voltage difference between a neutral point of the armature coils and a neutral point of the resistor circuit; determining a relationship between a signal representing the voltage difference obtained in said calculating step and a target value; and controlling an output of the inverter so that a specified efficiency is obtained based on the relationship between the signal representing the voltage difference and the target value determined by said determining step.
Claim 43
Dependent Claim
14 words
The method according to claim 32, wherein the specified efficiency is a peak efficiency.
Claim 44
Dependent Claim
61 words
The method according to claim 32, further comprising the step of: detecting a position of the rotor relative to the stator to obtain a position signal, wherein said controlling step adjusts a time interval from the position signal obtained by said detecting step to a voltage pattern switching signal so that the signal representing the voltage difference becomes the target value.
Claim 45
Dependent Claim
38 words
The method according to claim 32, wherein said step of determining a relationship determines a relationship between a level of an integral signal derived by integrating the voltage difference obtained by said calculating step and the target value.
Claim 46
Dependent Claim
40 words
The method according to claim 32, wherein said controlling step corrects the output voltage of the inverter so that the level of the signal representing the voltage difference becomes the target value, based on the result of said determining step.
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