Magnetic noise reduction method for AC rotary electric machine, and motor control apparatus and AC rotary electric machine apparatus using the same
First Claim
1. A magnetic noise reduction method for an AC rotary electric machine, wherein a radial vibration reducing harmonic current, whose frequency is n times (n is a natural number) the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is input into said armature by superimposing the radial reducing harmonic current on said polyphase AC current, thereby attenuating an (n−
- 1)th harmonic component, having a frequency (n−
1) times the frequency of said fundamental frequency component, that is contained in a radial vibration occurring radially about an axial center of a rotating shaft of said AC rotary electric machine due to an excitation force generated by said AC rotary electric machine or externally applied to said AC rotary electric machine.
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Abstract
The invention provides techniques for reducing or altering the magnetic noise of an AC rotary electric machine. A magnetic noise reducing harmonic current of order n, whose frequency is n times the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is superimposed on the polyphase AC current, thereby reducing or altering a harmonic component having a frequency (n−1) times the frequency of the fundamental frequency component and occurring due to a radial magnetic excitation force acting radially on an iron core of the AC rotary electric machine. Magnetic noise is caused by a vibration whose energy is the sum of the circumferential and radial vibrations of the iron core occurring due to the magnetomotive force of the rotor, and altering the radial vibration is particularly effective in altering the magnetic noise; as the harmonic component of the radially acting magnetic excitation force, occurring due to harmonic components having frequencies 3, 5, 7, and 13 times the fundamental frequency, has a frequency 6 or 12 times the fundamental frequency, the magnetomotive force of the rotor can be effectively reduced or altered when a current having a frequency 7 or 13 times the fundamental frequency is superimposed on the stator current.
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Citations
40 Claims
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1. A magnetic noise reduction method for an AC rotary electric machine, wherein a radial vibration reducing harmonic current, whose frequency is n times (n is a natural number) the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is input into said armature by superimposing the radial reducing harmonic current on said polyphase AC current, thereby attenuating an (n−
- 1)th harmonic component, having a frequency (n−
1) times the frequency of said fundamental frequency component, that is contained in a radial vibration occurring radially about an axial center of a rotating shaft of said AC rotary electric machine due to an excitation force generated by said AC rotary electric machine or externally applied to said AC rotary electric machine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- 1)th harmonic component, having a frequency (n−
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10. A motor control apparatus comprising:
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a rotational position detector which detects the rotational position of an automotive M-phase synchronous AC rotary electric machine (M is a positive integer not smaller than
3); anda motor current controller which applies, based on said detected rotational position, a prescribed phase current having a prescribed fundamental frequency and amplitude to each individual phase winding of an armature of said AC rotary electric machine, wherein said motor current controller applies a radial vibration reducing harmonic current having a frequency n times (n is a natural number) the frequency of the fundamental frequency component of said phase current to the each individual phase winding by superimposing said radial vibration reducing harmonic current on said phase current, and thereby attenuates an (n−
1)th harmonic component, having a frequency (n−
1) times the frequency of said fundamental frequency component, that is contained in a radial vibration occurring radially about an axial center of a rotating shaft of said AC rotary electric machine due to an excitation force generated by said AC rotary electric machine or externally applied to said AC rotary electric machine. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. An AC rotary electric machine apparatus comprising:
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an AC rotary electric machine having M-phase stator coils (M is a positive integer not smaller than
3);an inverter having a transistor device for controlling on and off a stator current for each phase of said synchronous machine; and an inverter control circuit which controls said transistor device on and off based on a detected or estimated rotation angle of said AC rotary electric machine, wherein said inverter control circuit includes harmonic PWM signal generator for performing processing to output to said inverter a harmonic PWM signal having a frequency n times (n is an integer not smaller than
2) the frequency of the fundamental frequency component of said stator current, and thereby a harmonic current having a frequency n times greater than the frequency of said fundamental frequency component is superimposed on said stator current and input into each of said rotor coils, and thus altering the amplitude of the magnetic sound of said AC rotary electric machine that has a frequency (n−
1) times the frequency of said fundamental frequency component, as compared to the case where said processing is not performed. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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38. A motor control apparatus comprising:
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a rotation angle detecting element which detects the rotational position of an automotive m-phase synchronous AC rotary electric machine (m is a positive integer not smaller than
3); anda motor current control element which applies, based on said detected rotational position, a phase current having a prescribed fundamental frequency and amplitude to each individual phase winding of an armature of said AC rotary electric machine, wherein said motor control apparatus further includes a phase current detecting element which detects the phase current flowing in each phase winding, and said motor current control element comprises; a phase current detection value coordinate system converting element which converts the detection value (in a stationary coordinate system) of each phase current into a d-q axis coordinate system (rotating coordinate system) rotating synchronously with the fundamental frequency component of said phase current specified by an output signal of said rotation angle sensor, and outputs a d-axis detection value Id and a q-axis detection value Iq; a fundamental command value output element which outputs a d-axis fundamental command value Id1* and a q-axis fundamental command value Iq1* as d- and q-axis components in said d-q axis coordinate system defining a fundamental command value as a target value of the fundamental frequency component of said phase current; a harmonic command value output element which outputs a d-axis harmonic command value Id6k+1* and a q-axis harmonic command value Iq6k+1* as d- and q-axis components in said d-q axis coordinate system defining a harmonic command value as a target value of a (6k+1)th harmonic current component (k is an integer and is 0 for said fundamental frequency component); a current deviation computing element which computes a d-axis current deviation Δ
Id and a q-axis current deviation Δ
Iq by calculating (Id1*)+(Id6k+1*)−
(Id) and (Iq*)+(Iq6k+1*)−
(Iq), respectively; anda phase voltage control element which asymptotically reduces said d-axis current deviation Δ
Id and said q-axis current deviation Δ
Iq toward zero by controlling the phase current to be applied to each phase winding, based on said d-axis current deviation Δ
Id and said q-axis current deviation Δ
Iq, and whereinsaid harmonic command value output element superimposes said d-axis harmonic command value Id6k+1* and said q-axis harmonic command value Iq6k+1* on said d-axis fundamental command value Id* and said q-axis fundamental command value Iq*, respectively, and thereby attenuates a 6k-th harmonic component, having a frequency 6k times the frequency of said fundamental frequency component, that is contained in a radial vibration occurring radially about an axial center of a rotating shaft of said AC rotary electric machine due to an excitation force generated by said AC rotary electric machine or externally applied to said AC rotary electric machine. - View Dependent Claims (40)
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39. A motor control apparatus comprising:
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a rotation angle detecting element which detects the rotational position of an automotive m-phase synchronous AC rotary electric machine (m is a positive integer not smaller than
3); anda motor current control element which applies, based on said detected rotational position, a phase current having a prescribed fundamental frequency and amplitude to each individual phase winding of an armature of said AC rotary electric machine, wherein said motor current control element comprises; a fundamental command value output element which outputs a d-axis fundamental command value Id1* and a q-axis fundamental command value Iq1* as d- and q-axis components in a d-q axis coordinate system defining a fundamental command value as a target value of the fundamental frequency component of said phase current; a harmonic command value output element which outputs a d-axis harmonic command value Id6k+1 * and a q-axis harmonic command value Iq6k+1* as d- and q-axis components in said d-q axis coordinate system defining a harmonic command value as a target value of a (6k+1)th harmonic current component (k is an integer and is 0 for said fundamental frequency component); a current command value computing element which computes a d-axis current command value Id* and a q-axis current command value Iq* by calculating (Id1*)+(Id6k+1*) and (Iq1*)+(Iq6k+1*), respectively; and a phase voltage control element which supplies to each phase winding the phase current corresponding to said d-axis current command value Id* and said q-axis current command value Iq* by controlling the phase current to be applied to said phase winding, based on said d-axis current command value Id* and said q-axis current command value Iq*, and wherein said harmonic command value output element superimposes said d-axis harmonic command value Id6k+1 * and said q-axis harmonic command value Iq6k+1* on said d-axis fundamental command value Id* and said q-axis fundamental command value Iq*, respectively, and thereby attenuates a 6k-th harmonic component, having a frequency 6k times the frequency of said fundamental frequency component, that is contained in a radial vibration occurring radially about an axial center of a rotating shaft of said AC rotary electric machine due to an excitation force generated by said AC rotary electric machine or externally applied to said AC rotary electric machine.
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Specification