CLAIMS [Claim 1
A control device for an AC rotary machine, which controls an AC rotary machine in which a rotor is rotated by a rotating magnetic field formed by a multi-phase alternating current flowing through an armature winding of a stator, the control device comprising:
an inverter that applies a voltage to the armature winding of the AC rotary machine;
an inverter connection unit that connects the armature winding to the inverter;
a magnetic field generator that generates an angle detecting magnetic field for detecting a rotation angle of the AC rotary machine by rotating in synchronization with the rotor;
an angle detector that detects two mutually orthogonal components of the angle detecting magnetic field generated by the magnetic field generator as a sine signal and a cosine signal; and a control calculation unit that controls a voltage applied to the inverter on the basis of a current command of the AC rotary machine and angle information obtained from the sine signal and the cosine signal,
wherein the control calculation unit includes an angle correction calculation unit that
corrects an error in the angle information caused by a noise magnetic field generated by a multi-phase alternating current flowing through the inverter connection unit by using a correction signal having a phase and an amplitude that are determined in accordance
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with a current vector of the multi-phase alternating current flowing through the inverter connection unit and a phase correction constant and an amplitude correction constant determined from a relative positional relationship between the inverter connection unit and the angle detector, and
outputs the corrected error as a corrected electrical angle, and the control calculation unit controls the inverter on the basis of the corrected electrical angle.
[Claim 2] The control device for an AC rotary machine according to claim 1, wherein
the angle information is either an electrical angle or a constant multiple of the electrical angle, and
the angle correction calculation unit calculates at least one of a sine signal correction signal and a cosine signal correction signal to be applied to the electrical angle as the correction signal,
calculates a difference between the sine signal and the sine signal correction signal as a corrected sine signal,
calculates a difference between the cosine signal and the cosine signal correction signal as a corrected cosine signal, and
outputs a corrected electrical angle obtained from the corrected sine signal and the corrected cosine signal as the corrected electrical angle.
[Claim 3] The control device for an AC rotary machine according
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to claim '1, wherein
the angle information is either a detection angle of the angle
detector or a constant multiple of the detection angle, and
when the number of pole pairs of the AC rotary machine is set as P and a shaft angle multiplier of the angle detector is set as Psns,
the angle correction calculation unit calculates at least one of a sine signal correction signal and a cosine signal correction signal to be applied to the detection angle as the correction signal,
calculates a difference between the sine signal and the sine signal correction signal as a corrected sine signal,
calculates a difference between the cosine signal and the cosine signal correction signal as a corrected cosine signal, and
outputs a corrected electrical angle calculated from a value obtained by multiplying a corrected detection angle, which is obtained from the corrected sine signal and the corrected cosine signal, by Kp = P/Psns.
[Claim 4] The control device for an AC rotary machine according to claim 2 or 3, wherein
When, among the sine signal and the cosine signal, a signal in which the error caused by the noise magnetic field is larger is set as a first signal and a signal in which the error caused by the noise magnetic field is smaller is set as a second signal,
the angle correction calculation unit calculates a first signai. correction signal to be applied to the first signal as the
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correction signal,
calculates a difference between the first signal and the first signal correction signal as a corrected first signal, and
outputs a corrected electrical angle obtained from the corrected first signal and the second signal as the corrected electrical angle.
[Claim 5] The control device for an AC rotary machine according to any one of claims 2 to 4, wherein the correction signal is a sine wave, and
has an amplitude value obtained by multiplying an absolute value of the current vector by the amplitude correction constant and has a phase value obtained by adding a first order phase, which serves as a fundamental period of the electrical angle or the corrected electrical angle, and the phase correction constant to a phase angle relative to a q axis of the current vector.
[Claim 6] The control device for an AC rotary machine according to claim 5, wherein
the angle detector is used in a saturation sensitivity region, and when the number of pole pairs of the AC rotary machine is set as P and a shaft angle multiplier of the angle detector is set as Psns,
the correction signal is a sine wave, and has an amplitude value obtained by multiplying the absolute value of the current vector by the amplitude correction constant and has
a phase value obtained by adding a (1 ± 2Psns/P)lh order phase of
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the electrical angle or the corrected electrical angle and the phase correction constant to the phase angle relative to the q axis of the current vector.
[Claim 7] The control device for an AC rotary machine according
to claim 5 or 6, wherein
the correction signal further includes a term relating to an nth
order sine wave, where n is a natural number not smaller than 2,
and
the nth order sine wave has an amplitude value obtained by multiplying the absolute value of the current vector by the amplitude correction constant and has
a phase value obtained by adding an nth order phase of the electrical angle or the corrected electrical angle and the phase correction constant to the phase angle relative to the q axis of the current vector.
[Claim 8] The control device for an AC rotary machine according to claim 7, wherein
the angle detector is used in a saturation sensitivity region, the correction signal further includes a term relating to an
(n ± 2Psns/P) th order sine wave, where n is a natural number not
smaller than 2, and
the (n ± 2Psns/P)Lh order sine wave has an amplitude value
obtained by multipiying the absolute value of the current vector
by the amplitude correction constant and has
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a phase value obtained by adding an (n + 2Psns/P) _1 order phase of the electrical angle or the corrected electrical angle and the phase correction constant to the phase angle relative to the q axis of the current vector.
[Claim 9] The control device for an AC rotary machine according to claim 1, wherein
the angle information is either an electrical angle or a constant multiple of the electrical angle, and
the angle correction calculation unit calculates an electrical angle correction signal to be applied to the electrical angle as the correction signal, and
outputs a difference between the electrical angle and the electrical angle correction signal as the corrected electrical angle.
[Claim 10]The control device for an AC rotary machine according
to claim 1, wherein
the angle information is either a detection angle of the angle
detector or a constant multiple of the detection angle, and
when the number of pole pairs of the AC rotary machine is set
as P and a shaft angle multiplier of the angle detector is set as
Psns,
the angle correction calculation unit calculates a detection
angle correction signal to be applied to the detection angle as
the correction signal, and
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outputs a corrected electrical angle calculated from a value obtained by multiplying a difference between the detection angle and the detection angle correction signal, which is obtained from the sine signal and the cosine signal, by Kp = P/Psns.
[Claim 11]The control device for an AC rotary machine according to claim 9 or 10, wherein
when the number of pole pairs of the AC rotary machine is set as P and a shaft angle multiplier of the angle detector is set as Psns,
the correction signal is a sine wave, and has an amplitude value obtained by multiplying the amplitude correction constant by an absolute value of the current vector and has a phase value obtained by adding a (1 ± 2Psns/P)'h order phase of the electrical angle or the corrected electrical angle and the phase correction constant to a phase angle relative to a q axis of the current vector.
[Claim 12]The control device for an AC rotary machine according
to claim 11, wherein
the correction signal further includes a term relating to an (n ± 2Psns/P) Lh order sine wave, where n is a natural number not smaller than 2, and
the (n + 2Psns/P)th order sine wave has an amplitude value obtained by multiplying the amplitude correction constant by the absolute value of the current vector and has
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a phase value obtained by adding an (n ± 2Psns/P) 1 order phase of the electrical angle or the corrected electrical angle and the phase correction constant to the phase angle relative to the g axis of the current vector.
[Claim 13]The control device for an AC rotary machine according to any one of claims 1 to 12, wherein
the armature winding is constituted by a first armature winding and a second armature winding,
the inverter is constituted by a first inverter that applies a voltage to the first armature winding and a second inverter that applies a voltage to the second armature winding,
the inverter connection unit is constituted by a first inverter connection unit that connects the first armature winding to the first inverter and a second inverter connection unit that connects the second armature winding to the second inverter, and
when a fault occurs in at least one of the second armature winding, the second inverter, and the second inverter connection unit, the angle correction calculation unit calculates the correction signal after replacing the phase correction constant and the amplitude correction constant with a phase correction constant and an amplitude correction constant for use during a fault.
[Claim 14] The control device for an AC rotary machine according
to any one of claims 1 to 12, wherein
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the armature winding is constituted by a first armature winding and a second armature winding,
the inverter is constituted by a first inverter that applies a voltage to the first armature winding and a second inverter that applies a voltage to the second armature winding,
the inverter connection unit is constituted by a first inverter connection unit that connects the first armature winding to the first inverter and a second inverter connection unit that connects the second armature winding to the second inverter,
the first inverter connection unit and the second inverter connection unit are disposed such that the noise magnetic field is canceled out in a position of the angle detector, and
when a fault occurs in at least one of the second armature winding, the second inverter, and the second inverter connection unit such that the noise magnetic field is not completely canceled out due to the fault, the angle correction calculation unit corrects the error in the electrical angle caused by the noise magnetic field.
[Claim 15]The control device for an AC rotary machine according to any one of claims 1 to 14, wherein the angle correction calculation unit uses a previously calculated value of the corrected angle information, calculated by the angle correction calculation unit, as the angle information.
[Claim 16] The control device for an AC rotary machine according to claim 15, wherein the angle correction calculation unit corrects
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the previously calculated value of the corrected angle information by adding thereto a product of a time from a previous calculation to a current calculation and a temporal variation rate of the angle information.
[Claim 17]The control device for an AC rotary machine according to any one of claims 1 to 16, wherein the control calculation unit obtains the current vector from the current command.
[Claim 18]The control device for an AC rotary machine according to any one of claims 1 to 16, further comprising a current detector that detects the multi-phase alternating current,
wherein the control calculation unit obtains the current vector from a detected current detected by the current detector.
[Claim 19]The control device for an AC rotary machine according to any one of claims 1 to 18, wherein the amplitude correction constant is commensurate with respective fundamental wave amplitudes of the sine signal and the cosine signal output by the angle detector.
[Claim 20]The control device for an AC rotary machine according to any one of claims 1 to 19, which is used to assist steering torque generated by an electric power steering.