JP2008043175A - Control unit for motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor control unit capable of preventing degradation of vibration/noise suppressing performance, while maintaining high vibration/noise suppressing performance, even if the radial force changes. <P>SOLUTION: A rotational angle of a 6-phase motor 24 is detected and an n-phase current supplied to the 6-phase motor 24 is detected. An n-phase/fourth converter 33 computes the d/q-axis current and the double-angle d/q axis current from the n-phase current and inputs the current into a current controller 19. A d/q axis current command portion 17 computes a d/q-axis current command value, and a current command correction portion 32 corrects the d/q axis and a double-angle d/q axis current command value corresponding to the rotation angle. The current controller 19 computes such a voltage command value, where the d/q axis and the double-angle d/q axis currents are a current command value, respectively. A 4-phase/n-phase converter 34 computes the n-phase voltage command value, from d/q axis and the double angle d/q axis voltage command values. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor control apparatus that corrects a current command value in vector control of an electric motor to suppress electromagnetic force ripple.

  For example, in motor vector control, the rotation angle and output current of the motor are detected, the deviation between the flux current command value and torque current command value and the output current is proportionally integrated, and each phase is calculated from the proportional integration result and the electrical angle. Is generated, and the electric motor is driven based on the voltage command value.

  FIG. 7A is a functional block diagram of the electric motor and its control device. An electric motor 11 shown in the figure is a general motor including a rotor and a stator. The rotor is fixed to a rotating shaft supported by a bearing, the stator faces the rotor, and the rotor is fixed. It is arranged concentrically with the shaft center and has a structure in which the stator and the bearing are held by the frame. As shown in FIG. 7B, three-phase windings 12, 13, and 14 are wound around the stator of the electric motor 11, and the windings (12a, 12b) (13a, 13b) (14a, 14b) are connected in parallel or in series. A rotating magnetic field is generated by the current supplied to the three-phase windings 12, 13, and 14 of the stator, and a rotational force is applied to the rotor.

The rotation angle of the electric motor 11 is detected by a rotation angle detection means 15 composed of a pulse generator such as an encoder and is input to the speed control system 16. The actual speed of the motor 11 is calculated from the rotation angle detection signal in the speed control system 16. The d / q-axis current command means 17 constituting the speed control system 16 calculates the d / q-axis current command values I _dc and I _qc in the orthogonal rotation coordinate system from the speed deviation signal between the speed command value and the calculated actual speed. Calculate. The d-axis current command value I _dc is a magnetic flux current command value that generates magnetic flux, and the q-axis current command value I _qc is a torque current command value that generates torque. The q-axis current command correction means 18 corrects the q-axis current command value I _qc based on the electrical angle obtained from the actual speed. The d-axis current command value I _dc and the corrected q-axis current command value I _qc are input to the current control means 19.

On the other hand, output currents I _uf , I _wf , and I _Vf supplied to the three-phase _windings 12, 13, and 14 of the electric motor 11 are detected by the current detection means 20. The three-phase / two-phase conversion means 21 takes in the three-phase current signals I _uf , I _wf , and I _Vf from the current detection means 20 and _performs three-phase / two-phase conversion. That is, the current signals I _uf , I _wf , and I _Vf shown in three phases in the stationary coordinate system are based on the electrical angle θ _e of the rotation angle detection signal, and the d / q axis current signals I _df and I _{qf in the} orthogonal rotation coordinate system. Is converted to The d / q axis current signals I _df and I _qf are input to the current control means 19. _{Conversion from} the current signals I _uf , I _wf , and I _{Vf in the} stationary coordinate system to the d / q axis current signals I _df and I _qf in the orthogonal rotation coordinate system is based on ( _Equation 1) and ( _Equation 2).

  In the above formula, the subscript d represents the d-axis component and q represents the q-axis component.

In the current control means 19, the deviation between the d / q-axis current command values I _dc and I _qc and the d / q-axis current signals I _df and I _qf is input to the PI controller for PI calculation (proportional integration calculation), Output as d / q axis voltage command values V _dc and V _qc in the orthogonal rotation coordinate system. The proportional integral calculation in the current control means 19 can be expressed by (Equation 3).

  Here, Kp is a proportional gain, Ki is an integral gain, and s is a Laplace operator.

The d / q axis voltage command values V _dc and V _qc output from the PI controller of the current control unit 19 are input to the two-phase / three-phase conversion unit 22. In the two-phase / three-phase conversion means 22, the d / q-axis voltage command values V _dc and V _qc are based on the electrical angle θ _e, and the voltage command values V _u , V _v , It is converted to V _w. The two-phase / three-phase conversion means 22 is based on ( _Equation 4), and the voltage command values V _u , V _v , V _{w of the} orthogonal stationary coordinate system indicated by three phases from the d / q axis voltage command values V _dc , V _qc. Convert to.

The driving unit 23 is configured to supply current signals I _uf , I _wf , which are driving signals to the windings 12, 13, 14 of each phase of the electric motor 11 based on the voltage command values V _u , V _v , V _w of the orthogonal stationary coordinate system. I _Vf is supplied. In this way, the output current based on the voltage command is supplied from the driving unit 23 to the electric motor 11.

  By the way, since a load is connected to the rotating shaft of the electric motor 11, rotation is transmitted from the rotating shaft to the load, while a radial force is applied from the load to the rotating shaft. When a radial force is applied to the rotating shaft of the electric motor, the rotating shaft is decentered, the gap between the stator and the rotor becomes non-uniform, and a radial electromagnetic force ripple occurs. Radial electromagnetic force ripple is a major cause of vibration and noise.

  Various countermeasures for reducing vibration and noise in an electric motor have been proposed. For example, one that corrects a drive current waveform based on electromagnetic force fluctuation information or electromagnetic force harmonic components (for example, refer to Patent Document 1), or one that controls a current flowing in a two-division winding for generating torque ( For example, refer to Patent Document 2), and the number of windings opposed to the stator is different (for example, refer to Patent Document 3).

  As in Patent Document 1, a case where the drive current waveform is corrected based on the electromagnetic force harmonic component will be considered.

When the torque current is corrected with the 2f harmonic component, the d / q-axis current command values I _dc and I _qc are ( _Equation 5) and ( _Equation 6).

Here, A _q represents a correction amplitude, and p _q represents a correction phase.

When the d / q-axis current command values I _dc and I _qc are input, the eccentric direction electromagnetic force F _x and the torque T are the constant terms of the rotation angle as in ( _Equation 7) and ( _Equation 8), and the 2f sine component 2f cosine component, 4f sine component, and 4f cosine component.

  Here, W is the magnetic energy inside the motor, x is the eccentric direction, the subscript s is the sine component, and c is the cosine component.

When the inductance is constant, the magnetic energy W inside the electric motor is (Equation 9).

Here, ψ _i represents the flux linkage with the stator, and I _i represents the current of the stator.

The interlinkage magnetic flux becomes (Equation 10) from the permeance and magnetomotive force distribution.

Here, f _i is the magnetomotive force distribution due to the stator coil, f _mag is the magnetomotive force distribution due to the permanent magnet of the rotor, P _g is the permeance between the rotor and the stator, and r is the average radius of the rotor and stator. , Z represents the axial (thrust) direction of the motor.

Permeance _{P g,} if there is eccentricity, it can be approximated as equation (11).

  Here, g represents an average gap between the stator and the rotor (x << g).

特開平１１−３４１８６４号公報 特開平１１−２７５８０２号公報 特開平１０−３１３５５７号公報 The magnetomotive force distribution f _i can be approximated by the sum of the following cosine functions, for example.

JP-A-11-341864 JP-A-11-275802 Japanese Patent Laid-Open No. 10-31557

  However, the device that corrects the drive current waveform as in Patent Document 1 can reduce the 4f electromagnetic force ripple with the 2f harmonic of the torque current, but cannot reduce the 2f electromagnetic force ripple. Therefore, vibration and noise due to the eccentricity of the electric motor cannot be sufficiently reduced.

  In addition, as in Patent Document 2, what controls the current flowing through the two-split winding for generating torque is in a motor using a 120 ° energization method, and in a motor using a 180 ° energization method. This limits the scope of application. Further, when the direction of the center of the winding and the direction of the radial force applied to the rotating shaft coincide with each other, there is a problem that it is not possible to reduce the electromagnetic force ripple that is shifted by 90 ° from the eccentric direction (orthogonal).

  In addition, the unbalanced winding as in Patent Document 3 has a problem in that when the radial force on the rotating shaft changes, the magnitude of the eccentricity also changes, resulting in deterioration of vibration / noise reduction performance.

  An object of the present invention is to provide an electric motor control device that has high vibration / noise reduction performance and does not deteriorate even when radial force changes.

  An electric motor control device according to the present invention is supplied to a drive means for driving an n-phase motor having five or more phases with an n-phase voltage command value, a rotation angle detection means for detecting a rotation angle of the motor, and the motor. current detection means for detecting an n-phase current, n-phase / four-phase conversion means for calculating a d / q-axis current and a double angle d / q-axis current from the n-phase current detected by the current detection means, and a d / q-axis Current command means for calculating a current command value; current command correction means for correcting d / q-axis and double-angle d / q-axis current command values corresponding to the rotation angle detected by the rotation angle detection means; and d / current control means for calculating a voltage command value such that the currents of the q-axis and the double-angle d / q-axis become current command values, respectively, and the voltages of the d / q-axis and the double-angle d / q-axis calculated by the current control means 4-phase / n-phase conversion means for calculating n-phase voltage command value from command value Characterized by including the.

  According to the present invention, it is possible to provide a motor control device that has high vibration / noise reduction performance and does not deteriorate the vibration / noise reduction performance even when the radial force applied to the rotating shaft of the motor changes.

(First embodiment)
FIG. 1A is a configuration diagram of a control device for an n-phase motor having five or more phases according to the first embodiment. In the present embodiment, the number n of phases of the n-phase motor 24 is assumed to be 6. In the following description, the n-phase motor 24 is referred to as a six-phase motor 24. The same elements as those in FIG. 7A are denoted by the same reference numerals, and redundant description is omitted.

  The six-phase motor 24 includes a stator and a rotor, and six-phase windings 25, 26, 27, 28, 29, and 30 are wound around the stator. The opposing windings (a, b) of each phase of the 6-phase windings 25-30 shown in FIG. 1 (b) are connected in parallel or in series.

  The rotation angle of the six-phase motor 24 is detected by the rotation angle detector 15 and a rotation angle detection signal is output in the form of a pulse signal. The rotation angle detection signal output from the rotation angle detection means 15 is input to a speed control system 31 that controls the speed of the six-phase motor 24.

In the speed control system 31, the actual speed of the six-phase motor 24 is calculated from the rotation angle detection signal, and the electrical angle θ _e is calculated based on the actual speed of the six-phase motor 24. Incidentally, it is also possible to incorporate computed by the rotation angle detecting means 15 electrical angle theta _e in the speed control system 31.

The d / q-axis current command means 17 calculates d / q-axis current command values I _dco and I _qco from the speed deviation signal between the actual speed and the speed command value of the six-phase motor 24. Further, the current command correction means 32 corrects the d / q axis current command values I _dco and I _qco and the double angle d / q axis current command value. Therefore, the current command correcting unit 32, based on the electrical angle theta _e, 6-phase generator of the motor 24 to correct the current command value so as to cancel the electromagnetic force ripple d2 / q2-axis current command correction signal dI _d2c, dI _q2c is calculated. The current command correction unit 32 is configured to calculate the d / q-axis current command values I _dc and I _qc calculated by ( _Equation 13) and the d2 / q2-axis current command values I _d2c and I which become the double-angle d / q-axis current command values. _q2c is output to the current control means 19.

Here, the d / q-axis current command values I _dc , I _qc , d2 / q2-axis current command values I _d2c , I _q2c are corrected by the current command correction means 32 with the d / q-axis current command values I _dco , I _qco , _respectively . It is the value. The d / q-axis current command values I _dc and I _qc to the current control means 19 are d-axis current command values (magnetic flux current command values) I _dc and q in the orthogonal rotation coordinate system when the six-phase motor 24 is vector-controlled. The shaft current command value (torque current command value) I _qc .

The current control means 19 receives d / q-axis current command values I _dc , I _qc , d2 / q2-axis current command values I _d2c , I _q2c , and an electrical angle θ _e in the orthogonal rotation coordinate system from the speed control system 31. The four-phase output current detection signals of the d / q axis and the double angle d / q axis are input from the n-phase / four-phase conversion means 33. In the current control means 19, the output current detected by the current detection means 20 changes the d / q axis current command values I _dc , I _qc , d2 / q2 axis current command values I _d2c , I _q2c , and the electrical angle θ _e . The drive signal to the drive means 23 is controlled so as to satisfy.

That is, the n-phase output current detected by the current detection means 20 is input to the n-phase / 4-phase conversion means 33. In the n-phase / four-phase conversion means 33, the current signal I _pnf indicated by the six phases in the stationary coordinate system from the current detection means 20 is converted into the current signal I _df indicated by the four phases of the orthogonal rotation coordinate system by ( _Equation 14), Convert to I _qf , I _d2f , and I _q2f .

The current control means 19 calculates the deviation between the current command value corrected by the current command correction means 32 and the output current detection signal converted into the d / q axis and d2 / q2 axis by the n-phase / 4-phase conversion means 33 from PI. and input to the controller executes the PI calculation (proportional integral calculation), orthogonal rotation coordinate system in d / q-axis voltage instruction value _{V dc, V qc} and d2 / q2-axis voltage command value _{V d2c,} outputs the _{V Q2C.} The d / q-axis voltage command values V _dc and V _qc and the d2 / q2-axis voltage command values V _d2c and V _q2c from the PI controller of the current control unit 19 are input to the 4-phase / n-phase conversion unit 34.

In four-phase / n-phase conversion means 33, d / q-axis voltage instruction value _{V dc, V qc} and d2 / q2-axis voltage command value _{V d2c,} the _{V Q2C,} based on the electrical angle theta _e, the equation (15) 6 It is converted into a voltage command value V _pn of the orthogonal stationary coordinate system indicated by the phase.

Here, the current command correction unit 32, current command correction signal _{dI d2c,} but calculates the _{dI Q2C,} current command correction signal _{dI d2c,} eccentric direction electromagnetic force _{F x} in the case of correcting the current command value with _{dI Q2C,} eccentric The (orthogonal) electromagnetic force F _y and the torque T shifted by 90 ° from the direction are the sum of a constant term of rotation angle, 2f sine component, and 2f cosine component as in (Equation 16) and (Equation 17).

  Here, W is the magnetic energy inside the motor, x is the eccentric direction, y is the direction orthogonal to the eccentric direction, the subscript s is the sine component, and c is the cosine component.

From the above equation, d2 / q2 axis current command correction signals dI _d2c and dI _q2c that reduce the 2f ripple of the eccentric direction electromagnetic force F _x are obtained so as to satisfy, for example, ( _Equation 19).

  As described above, by correcting the biaxial current command value of the double angle d / q axis (d2 axis and q2 axis), the 2f ripple of the electromagnetic force in the eccentric direction can be reduced.

  According to the first embodiment, since the double angle d / q-axis current command value of an n-phase motor having five or more phases is corrected, vibration and noise can be reduced.

  In the first embodiment, the reduction of the 2f electromagnetic force ripple has been described. However, depending on the number of phases n, the 4f electromagnetic force ripple or the like can be reduced.

In addition, the conversion formulas in the n-phase / 4-phase conversion means and the 4-phase / n-phase conversion means when reducing the 4f electromagnetic force ripple and the like are (Equation 20) and (Equation 21).

(Second Embodiment)
FIG. 2A is a configuration diagram of a control device for a three-phase two-wire motor according to the second embodiment of the present invention. In the second embodiment, a three-phase two-wire motor 35 is controlled instead of the six-phase motor 24 with respect to the first embodiment shown in FIG. The same elements as those in FIG.

  The three-phase two-wire motor 35 includes a stator and a rotor, and the three-phase windings 12, 13, and 14 do not align the center of the one-phase winding with the direction in which the radial force is applied to the stator. Two lines of windings (a, b) and (c, d) facing each other in each phase shown in FIG. 2B are connected in parallel or in series.

The current command correction means 32 receives the d / q-axis current command values I _dco and I _qco from the d / q-axis current command means 17 and is based on the electrical angle θ _e of the rotation angle detection signal. The double angle d / q axis current command correction signals dI _d2c and dI _q2c for correcting the current command value so as to cancel the electromagnetic force ripple generated by the electric motor 35 are calculated. Then, using the d / q-axis current command values I _dco and I _qco and the double angle d / q-axis current command correction signals dI _d2c and dI _q2c , the d / q-axis current command value I _dc , I _qc and double angle d / q-axis current command values I _d2c and I _q2c are calculated.

Here, the d / q-axis current command values I _dc and I _qc , the double angle d / q-axis current command values I _d2c and I _q2c are the d / q-axis current command values I _dco and I _qco , respectively. The value corrected by.

The current control unit 19 _receives the d / q-axis current command values I _dc and I _qc , the double angle d / q-axis current command values I _d2c and I _q2c , and the electrical angle θ _e in the orthogonal rotation coordinate system and inputs three-phases. The output current supplied to the two-wire motor 35 satisfies the d / q axis current command values I _dc and I _qc , the double angle d / q axis current command values I _d2c and I _q2c , and the electrical angle θ _e. The drive signal to the drive means 23 is controlled.

That is, the output current supplied to the three-phase two-wire motor 35 is detected by the current detection means 20 and input to the double three-phase / four-phase conversion means 36. In the double 3 phase / 4 phase conversion means 36, current signals I _u1f , I _v1f , I _w1f , I _u2f , I _v2f , I _w2f indicated by six phases in the stationary coordinate system inputted from the current detection means 20 are ( _Equation ( ₂₃₎ is converted into d / q-axis currents I _df and I _qf , and double angle d / q-axis currents I _d2f and I _q2f expressed in four phases of the orthogonal rotation coordinate system.

The current control means 19 inputs the d / q-axis current command values I _dc and I _q and the double angle d / q-axis current command values I _d2c and I _q2c from the current command correction means 32, while being doubled and three-phase / 4 The d / q axis currents I _df and I _qf and the double angle d / q axis currents I _d2f and I _q2f are input from the phase conversion means 36. Then, PI calculation (proportional integration calculation) is performed on the deviation between the current command value and the current signal by the PI controller. As a result, the d / q axis voltage command values V _dc and V _qc and the double angle d / q axis voltage command values V _d2c and V _q2c in the orthogonal rotation coordinate system are output from the current control means 19.

The d / q-axis voltage command values V _dc and V _qc and the double angle d / q-axis voltage command values V _d2c and V _q2c output from the current control unit 19 are input to the four-phase / 2-fold three-phase conversion unit 37. The In the four-phase / 2-fold three-phase conversion means 37, the d / q-axis voltage command values V _dc and V _qc and the double-angle d / q-axis voltage command values V _d2c and V _q2c are _{calculated based} on the electrical angle θ _e (several 24) is converted into voltage command values V _u1 , V _v1 , V _w1 , V _u2 , V _v2 , V _w2 of the orthogonal stationary coordinate system indicated by six phases.

Here, the current command correction unit 32, current command correction signal _{dI d2c,} but calculates the _{dI Q2C,} current command correction signal _{dI d2c,} eccentric direction electromagnetic force _{F x} in the case of correcting the current command value with _{dI Q2C,} eccentric The (orthogonal) electromagnetic force F _y shifted by 90 ° from the direction is the sum of constant terms of the rotation angle, such as (Equation 25) and (Equation 26), 2f sine component, and 2f cosine component.

  Here, W is the magnetic energy inside the motor, x is the eccentric direction, y is the direction orthogonal to the eccentric direction, the subscript s is the sine component, and c is the cosine component.

From the above equation, double angle d / q-axis current command correction signals dI _d2c and dI _q2c that reduce 2f ripple of the eccentric direction electromagnetic force F _x are obtained so as to satisfy, for example, ( _Equation 27).

  Thus, by correcting the biaxial current command value of the double angle d / q axis, the 2f ripple of the electromagnetic force in the eccentric direction can be reduced.

In the case where the direction applied centered and the radial force of one phase winding is matched, 2f sine component and 2f cosine component of the eccentric direction orthogonal electromagnetic force F _y is a double angle d / q-axis current command correction signal dI _d2c , _{DI q2c} .

  According to the second embodiment, the double angle d / q-axis current command value of the three-phase two-wire motor 35 in which the center of the one-phase winding is not aligned with the direction in which the radial force is applied is corrected. Therefore, vibration and noise caused by the 2f electromagnetic force ripple can be reduced.

(Third embodiment)
FIG. 3A is a configuration diagram of a control device for a two-split winding type three-phase motor according to a third embodiment of the present invention. In the third embodiment, a two-split winding type three-phase motor 38 is controlled as compared with the first embodiment shown in FIG. The same elements as those in FIG.

  The two-phase winding type three-phase motor 38 includes a stator and a rotor, and the three-phase windings 12, 13, and 14 coincide with the direction in which the radial force is applied to the center of the one-phase winding on the stator. The windings (a, b) facing each other shown in FIG. 3 (b) are divided and connected.

The current command correction means 32 receives the d / q axis current command values I _dco and I _qco from the d / q axis current command means 17 and is divided into two parts based on the electrical angle θ _e of the rotation angle detection signal. The half-angle d / q axis current command correction signals dI _{d1 / 2c} and dI _{q1 / 2c} for correcting the current command value so as to cancel the electromagnetic force ripple generated by the motor 38 are calculated. Then, the d / q-axis and half-angle d / q-axis current command values are corrected by (Equation 28).

Here, the d / q-axis current command values I _dc and I _qc and the half-angle d / q-axis current command values I _{d1 / 2c} and I _{q1 / 2c} are the d / q-axis current command values I _dco and I _qco , respectively. This is a value corrected by the correcting means 32.

The current control means 19 receives the d / q-axis current command values I _dc and I _qc , the half-angle d / q-axis current command values I _{d1 / 2c} and I _{q1 / 2c} in the orthogonal rotation coordinate system from the current command correction means 32, and the electrical while entering the angle theta _e, output current detection signal of the electric motor 38 is inputted from the half 3-phase / four-phase converter 39. The output current supplied to the motor 38 satisfies the d / q-axis current command values I _dc and I _qc , the half-angle d / q-axis current command values I _{d1 / 2c} and I _{q1 / 2c} , and the electrical angle θ _e . Thus, the drive signal to the drive means 23 is controlled.

That is, the output current of each phase supplied to the electric motor 38 is detected by the current detection means 20 and input to the half three-phase / 4-phase conversion means 39. The half three-phase / four-phase conversion means 39 converts the current signals I _ua , I _va , I _wa , I _ub , I _vb , I _wb indicated by six phases in the stationary coordinate system input from the current detection means 20 (several 29), the signals are converted into current signals I _df , I _qf , I _{d1 / 2f} , I _{q1 / 2f} indicated by four phases in the orthogonal rotation coordinate system.

In the current control means 19, the d / q-axis current command values I _dc and I _qc corrected by the current command correction means 32, the half-angle d / q-axis current command values I _{d1 / 2c} and I _{q1 / 2c} , and half three-phase Deviations from the current signals I _df , I _qf , I _{d1 / 2f} , and I _{q1 / 2f} output from the / 4-phase conversion means 39 in the four phases are subjected to PI calculation (proportional integration calculation) by the PI controller. As a result, the d / q-axis voltage command values V _dc and V _qc and the half-angle d / q-axis voltage command values V _{d1 / 2c} and V _{q1 / 2c} in the orthogonal rotation coordinate system are output from the current control means 19.

The d / q-axis voltage command values V _dc and V _qc and the half-angle d / q-axis voltage command values V _{d1 / 2c} and V _{q1 / 2c} output from the current control unit 19 are supplied to the four-phase / half-three-phase conversion unit 40. Entered. In the four-phase / half-three-phase conversion means 40, the d / q-axis voltage command values V _dc and V _qc and the half-angle d / q-axis voltage command values V _{d1 / 2c} and V _{q1 / 2c} are based on the electrical angle θ _e , The voltage command values V _ua , V _va , V _wa , V _ub , V _vb , V _wb of the orthogonal stationary coordinate system represented by six phases are converted by (Equation 30).

Here, the current command correction unit 32, current command correction signal dI _d1 / 2c, but calculates the dI _{q1 / 2c,} current command correction signal dI _d1 / 2c, eccentric direction electromagnetic when corrected by the dI _{q1 / 2c} The force F _x and the (orthogonal) electromagnetic force F _y shifted by 90 ° from the eccentric direction are the sum of the constant term of the rotation angle as in (Equation 31) and (Equation 32), the 2f sine component, and the 2f cosine component.

  Here, W is the magnetic energy inside the motor, x is the eccentric direction, y is the direction orthogonal to the eccentric direction, the subscript s is the sine component, and c is the cosine component.

From the above equation, half angle d / q-axis current command correction signal dI _d1 / 2c to reduce 2f ripple eccentric direction electromagnetic force _{F x,} the dI _{q1 / 2c,} determined so as to satisfy for example the (number 33).

  Thus, by correcting the biaxial current command value of the half-angle d / q axis, the 2f electromagnetic force ripple of the eccentric direction electromagnetic force can be reduced.

In the case that matches the direction applied centered and the radial force of one phase winding, the eccentric direction orthogonal electromagnetic force F _y of 2f sine component and 2f cosine component Hankaku d / q-axis current command correction signal dI d1 _{/ 2c} , DI _{q1 / 2c} .

  According to the third embodiment, the half angle d / q axis of the two-part winding of the two-part winding type three-phase motor 38 in which the center of the one-phase winding does not coincide with the direction in which the radial force is applied. Since the current command value is corrected, vibration and noise due to the 2f electromagnetic force ripple can be reduced.

(Fourth embodiment)
FIG. 4 is a configuration diagram of a motor control device according to the fourth embodiment of the present invention. In the fourth embodiment, parameter changing means 42 is provided with respect to the first embodiment shown in FIG. The same elements as those in FIG.

  The speed control system 41 includes parameter changing means 42 that changes the current command correction parameter of the current command correction means 32 in addition to the d / q axis current command means 17 and the current command correction means 32. The parameter changing unit 42 calculates the rotation frequency from the rotation angle detection signal, and changes the current command correction parameter of the current command correction unit 32 according to the rotation frequency.

Can be calculated rotational frequency from the time derivative or the like which is calculated from the rotation angle detection signal of the rotation angle detecting means 15 electrical angle theta _e, the rotation frequency resonates when close to the resonance frequency, vibration and noise Becomes larger.

Therefore, when the resonance frequency is close to the x direction, d2 / q2 axis current command correction signals dI _d2c and dI _q2c for reducing the 2f electromagnetic force ripple of the eccentric direction electromagnetic force F _x are set to satisfy, for example, ( _Equation 34). Ask.

When the resonance frequency is close to the y direction, the d2 / q2 axis current command correction signals dI _d2c and dI _q2c for reducing the 2f electromagnetic force ripple of the eccentric direction electromagnetic force F _y satisfy, for example, ( _Equation 35). Ask.

FIG. 5 shows the relationship between the resonance frequency and the rotation frequencies 2f and 4f. As shown in the figure, since the degree of resonance by the rotational speed is different, 2f and in the case the resonance frequencies are close, the eccentric direction electromagnetic force F _x of 2f electromagnetic force ripple reducing d2 / q2-axis current command correction signal dI _d2c and dI _q2c are determined so as to satisfy ( _Equation 36), for example.

Further, in the case 4f and the resonance frequency is close, eccentric direction electromagnetic force _{F y} of 4f electromagnetic force ripple reducing d4 / q4-axis current command correction signal _{dI d4c,} seek _{dI Q4c} to satisfy example (number 37).

  In this way, the parameter changing means 42 is operated by the current command correcting means 32 that is a parameter for current command correction so that the electromagnetic ripple of the eccentric electromagnetic force is reduced according to the rotational frequency of the six-phase motor 24. Change the power command correction signal.

  According to the fourth embodiment, the current command correction parameter is changed according to the rotational frequency of the six-phase motor 24. Therefore, vibration and noise in two directions (x direction and y direction) can be reduced. In addition, vibration and noise caused by ripples having different orders (2 electromagnetic force f ripple, 4f electromagnetic force ripple) can be reduced.

(Fifth embodiment)
FIG. 6 is a configuration diagram of an electric motor control device according to the fifth embodiment of the present invention. This fifth embodiment is different from the fourth embodiment shown in FIG. 4 in that the current command value to be corrected by the current command correcting unit 32 is replaced with a harmonic component instead of the parameter changing unit 42. Harmonic current command correction means 44 for correction is provided. The same elements as those in FIG. 4 are denoted by the same reference numerals, and redundant description is omitted.

The speed control system 43, in addition to the d / q-axis current command means 17 and the current command correction means 32, for example, a harmonic current command correction means for correcting d / q-axis current command values I _dc and I _qc with 2f harmonic components. 44. The harmonic current command correction means 44 corrects the d / q-axis current command values I _dc and I _qc with the 2f harmonic component _according to ( _Equation 38) and ( _Equation 39).

Here, A _d represents a correction amplitude, and p _d represents a correction phase.

The eccentric direction electromagnetic force F _x when the d / q-axis current command values I _dc and I _qc are input, the electromagnetic force F _y and the torque T shifted by 90 ° from the eccentric direction ( _Equation 40) ( _Equation 40) 41) It is the sum of the constant term of the rotation angle as in (Expression 42), the 2f sine component, the 2f cosine component, the 4f sine component, and the 4f cosine component.

  Here, W is the magnetic energy inside the motor, x is the eccentric direction, the subscript s is the sine component, and c is the cosine component.

From the above equation, the correction amplitude A _d , the correction phase p _d , and the d2 / q2 axis current command correction signals dI _d2c and dI _q2c that reduce the 2f ripple of the eccentric direction electromagnetic forces F _{x and} F _y satisfy, for example, ( _Equation 43). Asking.

  Thus, by correcting the d / q-axis current command correction signal and the d2 / q2-axis current command correction signal, it is possible to reduce the eccentric direction and the 2f ripple of the orthogonal electromagnetic force.

  According to the fifth embodiment, since the d / q-axis current command value of the six-phase motor 24 is corrected with harmonics, vibration and noise due to 2f electromagnetic force ripple can be reduced.

The harmonic current command correction means 44 may correct, for example, the d2 / q2 current command values I _d2c and I _q2c with the 2f harmonic component as shown in ( _Equation 44), ( _Equation 45), and ( _Equation 46). . In this case, the 4f ripple of electromagnetic force can be reduced.

  Here, A represents the correction amplitude, and p represents the correction phase.

The correction amplitude A, the correction phase p, and the d2 / q2 axis current command correction signals dI _d2co and dI _q2co that reduce the 2f electromagnetic force ripple of the electromagnetic force ripples F _{x and} F _y are obtained so as to satisfy, for example, ( _Equation 47).

  The harmonic current command correction means 44 may be provided in the motor control device of the second embodiment or the third embodiment.

The system block diagram of the control apparatus of the electric motor concerning the 1st Embodiment of this invention. The system block diagram of the control apparatus of the electric motor concerning the 2nd Embodiment of this invention. The system block diagram of the control apparatus of the electric motor concerning the 3rd Embodiment of this invention. The system block diagram of the control apparatus of the electric motor concerning the 4th Embodiment of this invention. Explanatory drawing which shows the relationship between 2f and 4f of a resonant frequency and rotational frequency. The system block diagram of the control apparatus of the electric motor concerning the 5th Embodiment of this invention. The system block diagram of the control apparatus of the conventional electric motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Three-phase motor, 12-14 ... Three-phase winding, 15 ... Rotation angle detection means, 16, 31, 41, 43 ... Speed control system, 17 ... d / q-axis current command means, 18 ... q-axis current command Correction means, 19 ... Current control means, 20 ... Current detection means, 21 ... 3-phase / 2-phase conversion means, 22 ... 2-phase / 3-phase conversion means, 23 ... Drive means, 24 ... 6-phase motor, 25-30 ... 6-phase winding, 32 ... Current command correction means, 33 ... n-phase / 4-phase conversion means, 34 ... 4-phase / n-phase conversion means, 35 ... 3-phase 2-wire motor, 36 ... double 3 phase / 4 Phase conversion means, 37... 4 phase / double 3 phase conversion means, 38... Split-winding three-phase motor, 39... Half 3 phase / 4 phase conversion means, 40... 4 phase / half 3 phase conversion means, 42 ... parameter changing means, 44 ... harmonic current command correcting means

Claims (5)

Driving means for driving an n-phase motor having five or more phases with an n-phase voltage command value;
Rotation angle detection means for detecting the rotation angle of the electric motor;
Current detection means for detecting an n-phase current supplied to the electric motor;
N-phase / four-phase conversion means for calculating a d / q-axis current and a double angle d / q-axis current from the n-phase current detected by the current detection means;
current command means for calculating a d / q-axis current command value;
Current command correction means for correcting d / q-axis and double-angle d / q-axis current command values corresponding to the rotation angle detected by the rotation angle detection means;
current control means for calculating a voltage command value such that the currents of the d / q axis and the double angle d / q axis become current command values;
4-phase / n-phase conversion means for calculating an n-phase voltage command value from the voltage command values of the d / q axis and the double angle d / q axis calculated by the current control means;
An electric motor control device comprising: Driving means for driving a three-phase two-wire motor with a center of one-phase winding not matched with a direction in which a radial force is applied with a three-phase voltage command value of two wires;
Rotation angle detection means for detecting the rotation angle of the three-phase two-wire motor;
Current detecting means for detecting a three-phase current of two wires of the three-phase two-wire motor;
A double three-phase / four-phase conversion means for calculating a d / q axis current and a double angle d / q axis current from the two-wire three-phase current detected by the current detection means;
current command means for calculating a d / q-axis current command value;
Current command correction means for correcting d / q axis and double angle d / q axis current command values corresponding to the rotation angle detected by the rotation angle detection means;
Voltage command for d / q axis and double angle d / q axis such that current of d / q axis and double angle d / q axis becomes the corrected d / q axis and double angle d / q axis current command values. Current control means for calculating a value;
4-phase / 2-fold 3-phase conversion means for computing a 3-wire voltage command value for two wires from the voltage command values for the d / q axis and double angle d / q axis;
An electric motor control device comprising: Drive means for driving a two-part winding type three-phase motor with a three-phase voltage command value so that the center of the one-phase winding does not coincide with the direction in which the radial force is applied;
Rotation angle detection means for detecting the rotation angle of the two-split winding motor;
Current detecting means for detecting a three-phase current of the two-split winding of the two-split winding motor;
Half three-phase / four-phase conversion means for calculating a d / q-axis current and a half-angle d / q-axis current from the three-phase current of the two-split winding detected by the current detection means;
current command means for calculating a d / q-axis current command value;
Current command correction means for correcting d / q-axis and half-angle d / q-axis current command values corresponding to the rotation angle detected by the rotation angle detection means;
Current for calculating the voltage command values for the d / q axis and the half angle d / q axis such that the currents of the d / q axis and the half angle d / q axis become the d / q axis and half angle d / q axis current command values. Control means;
4-phase / half-three-phase conversion means for calculating a three-phase voltage command value of the two-part winding from the d / q-axis and half-angle d / q-axis voltage command values;
An electric motor control device comprising:   4. A parameter changing unit that calculates a rotation frequency from a rotation angle of the rotation angle detection signal and changes a current command correction parameter in the current command correction unit based on the calculated rotation frequency. The control apparatus of the electric motor in any one of. 5. The motor control device according to claim 1, further comprising harmonic current command correction means for correcting a current command value to be corrected by the current command correction means with harmonics.

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