JP2009171781A - Controller for synchronous motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To guarantee the stability of the angle estimate of the position of a magnetic pole even when the angle error of the position of the magnetic pole is large. <P>SOLUTION: A reference-vector arithmetic means 111a obtains a reference vector as a reference for decision of the positive or negative angle error Δθ on the position of the magnetic pole for a synchronous motor 101 on the basis of the current detecting values i<SB>γ</SB>and i<SB>δ</SB>of γδ axis. An outer-product arithmetic means 111b arithmetically operates the outer product of a current-error vector e<SB>i</SB>corresponding to a deviation among current detecting values i<SB>γ</SB>and i<SB>δ</SB>and current estimates i<SB>γ#</SB>and i<SB>δ#</SB>and a reference vector v<SB>b</SB>. An angle and speed estimating appliance 116 computes an angle estimate θ<SB>#</SB>on the basis of an outer-product value e<SB>i</SB>×v<SB>b</SB>output from the outer-product arithmetic means 111b, and outputs the angle estimate to a rotational two-phase/three-phase coordinate conversion means 105 and a three-phase/rotational two-phase coordinate conversion means 106. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control apparatus for a synchronous motor, and is particularly suitable for application to a control method for driving a permanent magnet synchronous motor at a variable speed by position sensorless vector control.

Permanent magnet synchronous motors have the advantage of being smaller and more efficient than induction motors, and are applied to transportation fields such as electric vehicles and railway vehicles as well as elevators. In particular, an electric motor drive device in a transportation field such as a railway vehicle is required to be capable of variable speed operation and torque control in a wide range from a very low speed to a weak field operation range.
Further, in the control of a permanent magnet synchronous motor, position sensorless vector control capable of torque control without a position sensor may be used in order to reduce the cost associated with installation area restrictions, wiring of a rotary encoder and resolver, and maintenance.

  Various position sensorless vector control methods for permanent magnet synchronous motors have been proposed so far, but in Non-Patent Document 1, by using an observer that estimates current, particularly for control in a low speed region, A method for realizing permanent magnet synchronous motor speed sensorless vector control is disclosed. Non-Patent Document 2 discloses a method for realizing permanent magnet synchronous motor speed sensorless vector control by estimating an armature magnetic flux instead of an armature current.

FIG. 8 is a block diagram showing a schematic configuration of a conventional synchronous motor control device.
In FIG. 8, the embedded permanent magnet synchronous motor 001 is connected to a synchronous motor control device 000 that drives the embedded permanent magnet synchronous motor 001 at a variable speed, and is connected to the rotating shaft of the embedded permanent magnet synchronous motor 001. Is connected to a load 002.
Here, the synchronous motor control device 000 includes a power conversion device 004, a rotating two-phase / three-phase coordinate converting unit 005, a three-phase / rotating two-phase coordinate converting unit 006, a current control unit 007, and a current command value creating unit 008. , A speed PID regulator 009, an adaptive current observer 010, an inverse transfer function matrix calculating means 011, an angle / speed / primary resistance estimator 012, and subtractors 013, 014, 015 are provided, and the output side of the synchronous motor controller 000 Are provided with current detection means 003 for detecting UVW phase currents i _u , i _v , i _w supplied to the embedded permanent magnet synchronous motor 001.

  In the following description, the excitation axis may be expressed as γ axis or d axis, and the torque axis may be expressed as δ axis or q axis. In the following description, the value in the excitation axis direction is given a suffix of γ or d, the value in the torque axis direction is given a suffix of δ or q, and the value on the primary side is 1 or s. A suffix was added, and a secondary value was added with a suffix of 2 or r.

The subtractor 013 calculates a deviation between the speed command value ω ^* given to the synchronous motor control device 000 and the speed estimated value ω _{r #} output from the angle / speed / primary resistance estimator 012. Can do.
Speed PID controller 009, the deviation between the output velocity command value omega ^* and the speed estimated value omega _{r #} subtractor 013 so that the zero velocity command value omega ^* and the speed estimated value omega _{r #} and the The torque command value T ^* can be calculated by performing the PID calculation of the deviation.

The current command value creating means 008 can calculate the current command values i _γ ^* and i _δ ^* of the γδ axis based on the torque command value T ^* output from the speed PID controller 009. The axis estimated as the direction parallel to the magnetic pole of the magnet of the embedded permanent magnet synchronous motor 001 was taken as the γ axis, and the direction perpendicular to the γ axis was taken as the δ axis.
The three-phase / rotational two-phase coordinate conversion unit 006 converts the detected values of the UVW phase currents i _u , i _v , i _w detected by the current detection unit 003 into two-phase fixed αβ axes, By performing rotational coordinate conversion of the estimated angle value θ _# output from the primary resistance estimator 012, current detection values i _γ and i _δ on the γδ axis can be calculated.

The subtracters 014 and 015 are current command values i _γ ^* and i _δ ^* output from the current command value creation unit 008 and current detection values i _γ and i output from the three-phase / rotation two-phase coordinate conversion unit 006. Deviations from _δ can be calculated respectively.
The current control means 007 is a voltage command for the γδ axis so that the deviation between the current command values i _γ ^* and i _δ ^* output from the subtracters 014 and 015 and the detected current values i _γ and i _δ becomes zero. The values v _γ ^* and v _δ ^* can be calculated.
The rotating two-phase / three-phase coordinate conversion means 005 performs reverse rotation conversion of the voltage command values v _γ ^* and v _δ ^* of the γδ axis based on the estimated angle value θ _# output from the angle / speed / primary resistance estimator 012. Then, the voltage command values v _u ^* , v _v ^* , and v _w ^* can be calculated by performing the two-phase three-phase conversion after the conversion to the fixed two-phase value.

The power conversion device 004 drives the embedded permanent magnet synchronous motor 001 based on the voltage command values v _u ^* , v _v ^* , v _w ^* output from the rotating two-phase / three-phase coordinate conversion means 005. The embedded permanent magnet synchronous motor 001 can be controlled at a variable speed.
The adaptive current observer 010 can estimate the armature current based on the model of the embedded permanent magnet synchronous motor 001. Here, when estimating the armature current, the adaptive current observer 010 uses the armature resistance estimated value _{RS #} estimated by the angle / speed / primary resistance estimator 012 as a model of the embedded permanent magnet synchronous motor 001. Can be used as parameters.

Inverse transfer function matrix calculating unit 011, position estimation error Δθ axis deviation _# and the current detection value of the γδ-axis from resistance estimation error [Delta] R S _# armature i _gamma, i _[delta] and the current estimated value i _{gamma #,} i _{[delta] #} Is separated into a component proportional to the angle error and a component proportional to the resistance error, and the angle estimation error Δθ _# and the resistance estimation error ΔR _S are separated. _# Can be output.
The angle / speed / primary resistance estimator 012 is based on the angle estimation error Δθ _# and the resistance estimation error ΔR _{S #} output from the inverse transfer function matrix calculation unit 011, and the angle estimation value ω _{r #} = ω ₁ , angle estimation. The value θ _# and the armature resistance estimation value R _{S #} can be calculated.

When the speed command value ω ^* is given to the synchronous motor control device 000, a deviation between the speed command value ω ^* and the speed estimated value ω _{r #} output from the angle / speed / primary resistance estimator 012 is obtained. Calculated by the subtractor 013 and output to the speed PID adjuster 009. Then, the speed PID adjuster 009 performs PID calculation so that the deviation between the speed command value ω ^* and the speed estimated value ωr _# becomes zero, and the torque command value T ^* is transmitted to the current command value creating means 008 as a torque command. Outputs the value T ^* . Then, the current command value preparing unit 008 calculates receives a torque command value ^{T *} from the speed PID controller 009, a current command value i _gamma ^* based on the torque command value ^{T *,} the i _[delta] ^*, subtractor 014 , 015 respectively.

On the other hand, the current detection means 003 detects the UVW phase currents i _u , i _v , i _w supplied to the embedded permanent magnet synchronous motor 001 and sends the detected values to the three-phase / rotation two-phase coordinate conversion means 006. Output. The three-phase / rotation two-phase coordinate conversion means 006 converts the detected values of the UVW phase currents i _u , i _v , i _w into fixed two-phase conversion of the αβ axis, and then outputs them from the angle / velocity / primary resistance estimator 012. Current detection values i _γ and i _δ are calculated by performing the rotational coordinate conversion of the angle estimation value θ _# , and output to the subtracters 014 and 015, respectively.

When the subtracters 014 and 015 receive the current command values i _γ ^* and i _δ ^* and the current detection values i _γ and i _δ , respectively, the current command values i _γ ^* and i _δ ^* and the current detection value i _γ , I _δ are calculated and output to the current control means 007. Then, the current control unit 007 calculates the voltage command values v _γ ^* and v _δ ^* so that the deviation between the current command values i _γ ^* and i _δ ^* and the detected current values i _γ and i _δ becomes zero, Output to rotating two-phase / three-phase coordinate conversion means 005.

When the rotary two-phase / three-phase coordinate conversion means 005 receives the voltage command values v _γ ^* and v _δ ^* , the voltage based on the angle estimated value θ _# output from the angle / speed / primary resistance estimator 012. The command values v _γ ^* and v _δ ^* are reverse-rotated and converted into fixed two-phase values, and then two-phase and three-phase conversion is performed, so that the voltage command values v _u ^* , v _v ^* , and v _w ^* are Calculate and output to the power converter 004. Then, the power converter 004 drives the embedded permanent magnet synchronous motor 001 based on the voltage command values v _u ^* , v _v ^* , v _w ^* to change the embedded permanent magnet synchronous motor 001 to a variable speed. Control.

The detected current values i _γ and i _δ calculated by the three-phase / rotating two-phase coordinate conversion unit 006 are output to the adaptive current observer 010 and the voltage command value v _γ calculated by the current control unit 007. ^{* And} v _δ ^* are output to the adaptive current observer 010. Further, the armature resistance estimation value _{RS #} calculated by the angle / speed / primary resistance estimator 012 is output to the adaptive current observer 010.
Then, the adaptive current observer 010 uses the state equations relating to the current detection values i _γ and i _{δ on the} γδ axis and the current estimation values i _{γ #} and i _{δ #} on the γδ axis to thereby detect the current detection value i _{γ on} the γδ axis, Deviations (hereinafter also referred to as current errors) between i _δ and current estimated values i _{γ #} and i _{δ #} of the γδ axes are calculated and output to the inverse transfer function matrix calculating unit 011.
Here, the state equation regarding the current detection values i _γ and i _δ of the γδ axis and the current estimation values i _{γ #} and i _{δ #} of the γδ axis can be expressed by the following equation (1).

However,
v _γ : γ-axis output voltage v _δ : δ-axis output voltage i _γ : γ-axis current detection value i _δ : δ-axis current detection value L _d : d-axis inductance L _q : q-axis inductance Φ _m : magnet flux i _{γ #} : Γ-axis current estimated value i _{δ #} : δ-axis current estimated value R _{S #} : Armature resistance estimated value g ₁₁ , g ₁₂ , g ₂₁ , g ₂₂ : Feedback gain of the adaptive current observer 010.
Also, the feedback gain of the adaptive current observer 010 can be given by the following equation (2).

However,
g _c : Control variable that determines the pole of the adaptive current observer 010 (positive value)
It is.
When the inverse transfer function matrix calculating unit 011 receives the deviation between the detected current values i _γ and i _δ of the γδ axis and the estimated current values i _{γ #} and i _{δ #} of the γδ axis, Based on the inverse matrix of the transfer function up to the deviation between the detected value and the estimated value, the angle estimation error Δθ _# and the resistance estimation error ΔR _{S #} are calculated and output to the angle / velocity / primary resistance estimator 012.
Here, the transfer function from the angle estimation error Δθ _# and the resistance estimation error ΔR _{S #} to the deviation between the detected current values i _γ and i _δ of the γδ axis and the estimated current values i _{γ #} and i _{δ #} of the γδ axis The inverse matrix can be given by the following equation (3).

However, the coefficients B _{11 to} B ₂₂ can be set as in the following expression (4).

Further, in the equation (3), B ₁₁ B ₂₂ -B ₁₂ B ₂₁ includes a first-order term and a zero-order term of s, and the relationship between the coefficients B _{11 to} B ₂₂ is expressed by the following equation (5): Can be given.

そこで、

Therefore,

However, in consideration of a transient state, an unstable pole is included in the inverse matrix of the transfer function calculated by the inverse transfer function matrix calculating unit 011 and the closed loop transfer function from the actual angle θ to the angle estimation value θ _#. Need to be absent.
For this reason, when m ₀ ≧ 0, f (m ₀ ) = 1, and when m ₀ <0, f (m ₀ ) = − 1. When m ₀ m ₁ ≧ 0, h ₁ = | m ₁ |, h ₀ = | m ₀ |, and when m ₀ m ₁ <0, h ₁ = | m ₀ | + | m ₀ || m ₁ | k ′.
When the angle / velocity / primary resistance estimator 012 receives the angle estimation error Δθ _# and the resistance estimation error ΔR _{S #} , the speed estimation value ω _{r # is} obtained by using the following equations (7) to (9). = Ω ₁ , estimated angle value θ _#, and estimated armature resistance value R _{S #} can be calculated.

That is, when the angle / speed / primary resistance estimator 012 calculates the speed estimated value ω _{r #} = ω ₁ , the angle estimated value θ _# and the armature resistance estimated value R _{S #} , the speed estimated value ω _{r #} is subtracted. Is output to 013, and the estimated angle value θ _# is output to the rotating two-phase / three-phase coordinate converting means 005 and the three-phase / rotating two-phase coordinate converting means 006, and the armature resistance estimated value _{RS #} is supplied to the adaptive current observer 010. The adaptive current observer 010 can accurately output a current error proportional to the angle error Δθ.

However,
K _θp : Proportional gain of speed estimator K _θi : Integration gain of speed estimator K _Rp : Proportional gain of resistance estimator K _Ri : Integration gain of resistance estimator
As a result, the component proportional to the angle error Δθ of the magnetic pole position and the component proportional to the resistance error ΔR _s can be estimated separately, and embedded by position sensorless vector control while simultaneously identifying the armature resistance R _s. the write-type permanent magnet synchronous motor 001 since it is possible to variable speed drives, in the case where the armature resistance R _s varies also, it is possible to improve the positional accuracy of the low-speed range.

Hidehiko Sugimoto, Yasuyuki Noto, Toshie Kikuchi: “Position sensorless control with an armature winding resistance estimator for IPMSM using an adaptive current observer”, 2007 IEEJ National Convention, 4-119 Satoshi Murakami, Taiki Kanno, Kenji Kamai, Yoichi Hayashi, Tetsuya Fukumoto: “Design method of permanent magnet synchronous motor speed sensorless vector control system using adaptive observer”, IEEJ Semiconductor Power Conversion Study Group, SPC-02-85

However, in the method disclosed in Non-Patent Document 1, the armature resistance R _s can be identified at the same time and the position accuracy in the low speed region can be improved. However, in deriving the coefficients B _{11 to} B ₂₂ , Assuming that Δθ≈0, values including the angle error Δθ are approximated as cos Δθ≈cos 2Δθ≈1, sin Δθ≈Δθ, sin 2Δθ≈2Δθ. Therefore, if the angle error Δθ of the magnetic pole position becomes large and the assumption that Δθ≈0 is not satisfied, the calculation accuracy of the angle estimation error Δθ _# deteriorates. There is a problem that the stability when driving a large motor cannot be guaranteed.
Even in the method disclosed in Non-Patent Document 2, a similar problem may be caused because a similar approximation is used.
Therefore, an object of the present invention is to provide a control apparatus for a synchronous motor that can guarantee the stability of an estimated value of a magnetic pole position even when the angle error of the magnetic pole position is large.

  In order to solve the above-described problem, according to the control apparatus for a synchronous motor according to claim 1, the armature current is estimated based on the current detection means for detecting the armature current of the synchronous motor and the model of the synchronous motor. An adaptive current observer, a reference vector calculation means for calculating a reference vector serving as a reference for determining whether the angle error of the magnetic pole position of the synchronous motor is positive, a current detection value detected by the current detection means, and the adaptive current Based on the outer product value calculated by the outer product calculating means, the outer product calculating means for calculating the outer product of the current error vector corresponding to the deviation from the current estimated value estimated by the observer and the reference vector, Based on an angle estimator for calculating an estimated angle value of the magnetic pole position of the synchronous motor and a voltage command value generated using the estimated angle value, the synchronous motor is controlled at a variable speed. Characterized in that it comprises a power converter.

  According to the control apparatus for a synchronous motor according to claim 2, current detection means for detecting an armature current of the synchronous motor, an adaptive current observer for estimating an armature current based on a model of the synchronous motor, Reference vector calculation means for calculating a reference vector serving as a reference for determining whether the angle error of the magnetic pole position of the synchronous motor is positive, a current detection value detected by the current detection means, and a current estimated by the adaptive current observer A cross product calculation means for calculating a cross product of the current error vector corresponding to the deviation from the estimated value and the reference vector, a code calculation means for calculating a sign of the cross product value calculated by the cross product calculation means, and the synchronization A monotonically increasing function computing means for computing a monotonically increasing function with respect to the magnitude of the angle error of the magnetic pole position of the electric motor; and a function computed by the monotonically increasing function computing means; An angle estimator that calculates an angle estimated value of the magnetic pole position of the synchronous motor based on a multiplication result with the code calculated by the code calculating means, and a voltage command value generated using the angle estimated value And a power conversion device that performs variable speed control of the synchronous motor.

According to the control apparatus for a synchronous motor according to claim 3, the monotonously increasing function calculating means includes an inner product calculating means for calculating an inner product of the current error vector and the reference vector.
Further, according to the control apparatus for a synchronous motor according to claim 4, the angle estimator calculates the sign to an outer product value calculated by the outer product calculating means and an inner product value calculated by the inner product calculating means. The angle estimated value of the magnetic pole position of the synchronous motor is calculated based on the addition result with the value obtained by multiplying the sign calculated by the means.
According to the synchronous motor control apparatus of claim 5, the reference vector is an integrated value of the inductance difference between the dq axes and the torque axis current, and a range from −1 to 1 times the magnetic flux. The value that is proportional to the sum of the values that fall into the magnetic flux axis component, and the torque axis component that has a value that is proportional to the sum of the difference in inductance between the dq axes and the magnetic flux axis current, and the sum of the magnet flux It is characterized by.

  As described above, according to the present invention, by calculating a reference vector serving as a reference for determining whether the angle error of the magnetic pole position of the synchronous motor is positive or negative, the synchronous motor can be obtained without performing an approximation that is valid when the angle error is small. The estimated angle value of the magnetic pole position can be calculated, and the stability of the estimated angle value of the magnetic pole position can be ensured even when the angle error of the magnetic pole position is large.

Hereinafter, a control apparatus for a synchronous motor according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a synchronous motor control device according to a first embodiment of the present invention.
In FIG. 1, a controller 100 for a synchronous motor that drives the embedded permanent magnet synchronous motor 101 at a variable speed is connected to the embedded permanent magnet synchronous motor 101. Is connected to a load 102.

Here, the synchronous motor control device 100 includes a power conversion device 104, a rotating two-phase / three-phase coordinate converting means 105, a three-phase / rotating two-phase coordinate converting means 106, a current control means 107, and a current command value creating means 108. , A speed PID adjuster 109, an adaptive current observer 110, a reference vector calculation means 111a, a cross product calculation means 111b, an angle / speed estimator 116, and subtractors 113, 114, 115 are provided on the output side of the synchronous motor control apparatus 100 Are provided with current detection means 103 for detecting UVW phase currents i _u , i _v , i _w supplied to the embedded permanent magnet synchronous motor 101.

  It should be noted that the power converter 104, the rotating two-phase / three-phase coordinate converting means 105, the three-phase / rotating two-phase coordinate converting means 106, the current control means 107, the current command value creating means 108, the speed PID adjuster 109, the adaptive current observer. 110, subtractors 113, 114, and 115 are the power conversion device 004, rotating two-phase / three-phase coordinate converting means 005, three-phase / rotating two-phase coordinate converting means 006, current control means 007, and current command value generation in FIG. Operations similar to those of the means 008, the speed PID adjuster 009, the adaptive current observer 010, and the subtracters 013, 014, and 015 can be performed.

The reference vector calculation unit 111a includes the current detection values i _γ and i _δ output from the three-phase / rotation two-phase coordinate conversion unit 106 and the current estimation values i _{γ #} and i _{δ #} estimated by the adaptive current observer 110. It is possible to calculate a reference vector serving as a reference for determining whether the angle error Δθ of the magnetic pole position of the synchronous motor 101 is positive or negative with respect to the current error vector corresponding to the deviation. This reference vector falls within the range from −1 to 1 times the integrated value of the inductance difference (L _d −L _q ) between the dq axes and the δ axis current detection value i _δ and the magnet flux Φ _m. The value proportional to the sum of the _input value and the sum of the magnetic flux component, the integrated value of the inductance difference between the dq axes (L _d −L _q ) and the detected γ-axis current value i _γ , and the magnetic flux Φ _m A value proportional to the value can be provided as a torque axis component.

The outer product calculation unit 111b is configured to calculate a current error vector corresponding to a deviation between the current detection values i _γ and i _δ and the current estimation values i _{γ #} and i _{δ #} and a reference vector calculated by the reference vector calculation unit 111a. Cross product can be calculated.
The angle / speed estimator 116 can calculate the speed estimated value ω _{r #} (= primary frequency ω ₁ ) and the angle estimated value θ _# based on the outer product value output from the outer product calculating unit 111b.
Then, the current detection values i _γ and i _δ calculated by the three-phase / rotation two-phase coordinate conversion unit 106 are output to the adaptive current observer 110 and the reference vector calculation unit 111 a and are calculated by the current control unit 107. The voltage command values v _γ ^* and v _δ ^* are output to the adaptive current observer 110. Further, the primary frequency ω ₁ calculated by the angle / speed estimator 116 is output to the adaptive current observer 110, the subtractor 113, and the reference vector calculation means 111a.

Then, the adaptive current observer 110 uses the state equations regarding the current detection values i _γ and i _δ of the γδ axis and the current estimation values i _{γ #} and i _{δ #} of the γδ axis, thereby detecting the current detection value i _γ of the γδ axis, Deviations between the current estimation values i _{γ #} and i _{δ #} on the i _δ and γδ axes are calculated, respectively, and the detected current values i _γ and i _δ on the γδ axis and the current estimation values i _{γ #} and i _{δ #} on the γδ axis are calculated. Is output to the reference vector computing means 111a.
When the reference vector calculation unit 111a receives the detected current values i _γ and i _δ of the γδ axis, the reference vector calculation unit 111a calculates a reference vector serving as a reference for determining whether the angle error Δθ of the magnetic pole position of the synchronous motor 101 is positive or negative, thereby calculating an outer product. Output to the means 111b.
Here, the reference vector v _b = [v _bγ , v _bδ ] ^T can be given by the following equation (10).

However, alpha represents the adjustment value may vary within the range from - [Phi] _m to [Phi _m, it may be adjusted according to the load current.
Note that in (10), the reference vector v _b the value of gamma axis L _d, the value of δ axis of the reference vector v _b is being divided respectively L _q, a value proportional to the current error, gamma The current error of the axis may be multiplied by L _d and the current error of the δ axis may be multiplied by L _q to be used as the reference vector v _b . In this case, the division operation by the inductance of the denominator in the equation (10) is omitted. can do.

Next, the outer product calculation means 111b receives the deviation between the detected current values i _γ and i _δ of the γδ axis and the estimated current values i _{γ #} and i _{δ #} of the γδ axis from the adaptive current observer 110 and also uses the reference vector v _b. Is received from the reference vector computing means 111a, the outer product of the current error vector e _i corresponding to the deviation between the detected current values i _γ and i _δ and the estimated current values i _{γ #} and i _{δ #} and the reference vector v _b is obtained. The outer product value e _i × v _b is output to the angle / speed estimator 116.
Here, the outer product value e _i × v _b can be given by the following equation (11).

However,
e _i = [i _γ −i _{γ #} , i _δ −i _{δ #} ] ^T is a current error vector v _b = [v _bγ , v _bδ ] ^T is a reference vector,
ξ is an angle formed by the current error vector e _i and the reference vector v _b .
Next, the angle / speed estimator 116 calculates the speed estimated value ω _{r #} (= primary frequency ω ₁ ) and the angle estimated value θ _# based on the outer product value e _i × v _b output from the outer product calculating unit 111b. calculate. Then, the angle / speed estimator 116 uses the primary frequency ω ₁ as the adaptive current observer 110, the subtractor 113 and the reference vector calculation means 111a, and the angle estimated value θ _# as the rotation two-phase / three-phase coordinate conversion means 105 and the three-phase / Output to the rotating two-phase coordinate transformation means 106.
Here, the primary frequency ω ₁ and the estimated angle value θ _# can be given by the following equation (12).

This makes it possible to determine whether the angle error Δθ is positive or negative with reference to the reference vector v _b , and calculate the estimated angle value θ _# of the magnetic pole position of the synchronous motor 101 without performing approximation that holds when the angle error Δθ is small. Therefore, even when the angle error Δθ of the magnetic pole position is large, it is possible to guarantee the stability of the estimated angle value θ _# of the magnetic pole position.

FIG. 2 is a diagram showing a calculation method of the outer product calculated by the outer product calculation means of FIG.
In FIG. 2, the current error vector e _i connects the position of the current error corresponding to the deviation between the detected current values i _γ and i _δ and the estimated current values i _{γ #} and i _{δ #} from the origin on the γδ plane. Can be expressed as The angle formed between the current error vector e _i and the reference vector v _b can be represented by ξ.

Here, the position of the current error, when the angle error Δθ is positive, present in the right side of the straight line including the reference vector v _b, when the angle error Δθ is negative, the straight line including the reference vector v _b Exists on the left side. Further, the signs of the angle error Δθ and sin ξ coincide. Therefore, the sign of the angle error Δθ can be determined by calculating the outer product value e _i × v _b of the current error vector e _i and the reference vector v _b . In a range where the angle error Δθ is small, a value proportional to the angle error Δθ can be calculated.

Hereinafter, when the angle error Δθ is positive, it becomes cross product value e _i × v _b is positive, when the angle error Δθ is negative will be described why the cross product value e _i × v _b is negative. In addition, the operating conditions will be clarified.
The deviations between the detected current values i _γ and i _δ on the γδ axis and the estimated current values i _{γ #} and i _{δ #} on the γδ axis without using the approximations of cos Δθ≈1 and sin Δθ≈Δθ can be summarized as (13 ) Expression.

However, assuming that the estimated value of the rotational speed of the embedded permanent magnet synchronous motor 101 and the actually measured value are the same, ω ₁ = ω _r was set.
(13) the trajectory of the current error vector e _i of the formula passes through the origin when [Delta] [theta] = 0. Further, by substituting Δθ = −1 / 2π and Δθ = 1 / 2π into the equation (13), the following equation (14) is obtained.

However, the steady state assumed with respect to the position of the current error vector e _i, and substituting s = 0.
3 and FIG. 5 are diagrams showing the relationship between the locus of the current error vector used in the outer product calculation means of FIG. 1 and the angle error, and FIG. 4 is a diagram showing the definition of the current error vector of FIG.
In FIG. 3, when the position of the current error on the γδ plane when Δθ = 1 / 2π is point R, and the position of the current error on the γδ plane when Δθ = −1 / 2π is point Q, the origin and the point A straight line connecting _R is l _R , and a straight line connecting the origin and the point Q is l _Q.

In the present embodiment, alpha = - [Phi] _m and the reference vector v point coordinates _b Q when, alpha = [Phi _m and the coordinates of the reference vector v _b in time coincides with the point R. For this reason, when the adjustment value α is set in the range from −Φ _m to Φ _m , the coordinates of the reference vector v _b exist between the point Q and the point R.
When the angle error Δθ is in the range from −90 degrees to 0 degrees, the current error vector e _i exists on the left side of the straight line l _Q , and the angle error Δθ is in the range from 0 degrees to 90 degrees. If the current error vector e _i exists on the right side of the straight line l _R , the sign of the angle error Δθ is determined from the outer product value e _i × v _{b of} the current error vector e _i and the reference vector v _b. be able to.

Here, as shown in FIG. 4, the relationship between the current error vector w ₀ when the angle error is Δθ and the current error vector w ₁ when the angle error obtained by adding a positive minute value ε is (Δθ + ε) is considered. .
If there is a current error vector e _i located on the left side of the straight line l _{R in} the current error vector e _{i in} which the angle error Δθ is in the range from 0 degrees to 90 degrees, the dotted line in FIG. There is a locus that goes to the point R through the left side of the straight line shown. In the locus toward the point R through the left side of this straight line, the current error vector w ₁ exists on the right side of the current error vector w ₀ .

Further, in the angle error Δθ is -90 degrees of the current error vector e _i in the range of 0 °, assuming that there is a current error vector e _i on the right side of the straight line l _Q, the dotted line in FIG. 5 There is a locus that goes to the point Q through the right side of the straight line. Here, considering the positional relationship between the current error vectors w ₀ and w ₁ , since ε> 0, the current error vector w ₀ is close to the current error vector e _i when the angle error Δθ is −90 degrees, If the current error vector w ₁ is close to the origin. For this reason, the current error vector w ₁ is present on the right side of the current error vector w _{0 in} the locus toward the point Q through the right side of the straight line indicated by the dotted line in FIG.

Assuming such a trajectory, calculating the cross product value w ₀ × w ₁ of the current error vector w ₀ current error vector w ₀ based _on, w _1, the cross product value w ₀ × w ₁ becomes negative.
On the other hand, if the outer product value w ₀ × w ₁ is always positive regardless of the angle error Δθ and the parameters, the straight line l _Q when the angle error Δθ is in the range from −90 degrees to 0 degrees. right to the current error vector e _i never exists in the case where the angle error Δθ is within the range from 0 degrees to 90 degrees, the line l left current error vector e _i of _R is present Absent.
Next, when the outer product value w ₀ × w ₁ of the current error vectors w ₀ and w ₁ is actually calculated, the following equation (15) is obtained. In the equation (15), assuming that the minute value ε is close to ₀ , a value obtained by differentiating the current error vectors w ₀ and w ₁ by the angle error Δθ is used.

  However, in deriving the equation (15), the relationship of the following equation (16) was used.

Next, when the equation (13) representing the current error vector e _i is differentiated by the angle error Δθ, the following equation (17) is obtained.

Using this equation (17), calculating the equation (15) _{e iγ (Δθ) e iδ (} Δθ)'e iγ (Δθ)'e iδ (Δθ), the following equation (18) is obtained .

In this equation (18), if the angle error Δθ is in the range from −90 degrees to 90 degrees, cos Δθ ≧ 0. Further, (1−cos Δθ) ≧ 0 when the angle error Δθ is within a range of −90 degrees to 90 degrees.
Further, in the embedded permanent magnet synchronous motor 101, the reluctance torque is effectively used, and thus the γ-axis current detection value i _γ is limited to 0 or a negative value in normal operation. Under such conditions, the first term of equation (18) is positive.
Accordingly, if the angular error Δθ is in the range from −90 degrees to 90 degrees and the γ-axis current detection value i _{γ is} 0 or a negative value, the terms of the expression (18) are all 0. Or positive.

On the other hand, in the equation (15), since the minute value ε is a positive value, the outer product value w ₀ × w ₁ is 0 or positive under such conditions.
Therefore, under such conditions, when the angle error Δθ is in the range from −90 degrees to 0 degrees, the current error vector e _i does not exist on the right side of the straight line l _Q , and the angle error when Δθ is within the range from 0 degrees to 90 degrees, it does not line l left current error vector e _i of _R is present.

From the above, the reference coordinates are set in the region sandwiched between the straight lines l _Q and l _R , and the position of the reference vector v _b connecting the reference coordinates and the origin and the current error vector e _i. Examining the relationship, when the angle error Δθ is positive, the current error vector e _i is on the right side of the reference vector v _b , and when the angle error Δθ is negative, the current error vector e _i is the reference vector v _b. You can see that it is on the left side. Therefore, the direction of the angle error Δθ can be determined by calculating the outer product value e _i × v _b of the reference vector v _b and the current error vector e _i .

This relationship is established under normal operating conditions where i _γ ≦ 0 in the embedded permanent magnet synchronous motor 101 that satisfies the condition of L _q > L _d , and when the salient pole ratio is large or the magnet magnetic flux Φ _m is large. But you can get similar results. Further, the angle error Δθ is effective within a range of −90 degrees to 90 degrees, and even when the angle error Δθ is large, the position estimation system is stable in that it does not become a positive feedback.

FIG. 6 is a block diagram showing a schematic configuration of the synchronous motor control device according to the second embodiment of the present invention.
In FIG. 6, the embedded permanent magnet synchronous motor 201 is connected to a synchronous motor control device 200 that drives the embedded permanent magnet synchronous motor 201 at a variable speed, and is connected to the rotating shaft of the embedded permanent magnet synchronous motor 201. Is connected to a load 202.
Here, the synchronous motor control device 200 includes a power conversion device 204, a rotating two-phase / three-phase coordinate converting means 205, a three-phase / rotating two-phase coordinate converting means 206, a current control means 207, and a current command value creating means 208. , Speed PID adjuster 209, adaptive current observer 210, reference vector calculation means 211a, outer product calculation means 211b, angle / speed estimator 216, subtractors 213, 214, 215, inner product calculation means 211c, sign calculation means 217, multiplication means 218, a gain adjusting means 219, and an adder 220 are provided, and UVW phase currents i _u , i _v and i _w supplied to the embedded permanent magnet synchronous motor 201 are provided on the output side of the synchronous motor control device 200. Current detecting means 203 for detecting is provided.

  Note that the power converter 204, the rotating two-phase / three-phase coordinate converting means 205, the three-phase / rotating two-phase coordinate converting means 206, the current controlling means 207, the current command value creating means 208, the speed PID adjuster 209, the adaptive current observer. 210, subtracters 213, 214, 215, reference vector calculation means 211a, outer product calculation means 211b, angle / speed estimator 216, power conversion device 104, rotary two-phase / three-phase coordinate conversion means 105 in FIG. / Rotating two-phase coordinate conversion means 106, current control means 107, current command value creation means 108, speed PID adjuster 109, adaptive current observer 110, subtractors 113, 114, 115, reference vector calculation means 111a, outer product calculation means 111b The same operation as that of the angle / speed estimator 116 can be performed.

The inner product calculation unit 211c is configured to calculate a current error vector corresponding to a deviation between the current detection values i _γ and i _δ and the current estimation values i _{γ #} and i _{δ #} and a reference vector calculated by the reference vector calculation unit 111a. The inner product can be calculated.
The sign calculation means 217 can calculate the sign of the outer product value calculated by the outer product calculation means 211b.
The multiplying unit 218 can multiply the inner product value calculated by the inner product calculating unit 211c by the code calculated by the code calculating unit 217.
The gain adjusting unit 219 can multiply the multiplication result calculated by the multiplying unit 218 by the adjustment gain k.

The adder 220 can add a value obtained by multiplying the multiplication result calculated by the multiplying unit 218 by the adjustment gain k and the outer product value calculated by the outer product calculating unit 211b.
Then, the current detection values i _γ and i _δ calculated by the three-phase / rotation two-phase coordinate conversion unit 206 are output to the adaptive current observer 210 and the reference vector calculation unit 211a and calculated by the current control unit 207. The commanded voltage values v _γ ^* and v _δ ^* are output to the adaptive current observer 210. Further, the primary frequency ω ₁ calculated by the angle / speed estimator 216 is output to the adaptive current observer 210, the subtractor 213, and the reference vector calculation means 211a.

Then, the adaptive current observer 210 uses the state equations relating to the current detection values i _γ and i _δ of the γδ axis and the current estimation values i _{γ #} and i _{δ #} of the γδ axis to thereby detect the current detection value i _γ of the γδ axis, Deviations between the current estimation values i _{γ #} and i _{δ #} on the i _δ and γδ axes are calculated, respectively, and the detected current values i _γ and i _δ on the γδ axis and the current estimation values i _{γ #} and i _{δ #} on the γδ axis are calculated. Is output to the reference vector computing means 211a.
When the reference vector calculation means 211a receives the detected current values i _γ and i _δ of the γδ axis, the reference vector calculation means 211a calculates a reference vector serving as a reference for determining whether the angle error Δθ of the magnetic pole position of the synchronous motor 201 is positive or negative, and calculates an outer product. It outputs to the means 211b and the inner product calculating means 211c.
Here, the reference vector v _b = [v _bγ , v _bδ ] ^T can be given by the following equation (19).

The reference vector v _{b in the} equation (19) is obtained by fixing the adjustment value α of the reference vector v _{b in} the equation (10) to 0.
Next, the outer product calculation means 211b receives the deviation between the detected current values i _γ and i _δ of the γδ axis and the estimated current values i _{γ #} and i _{δ #} of the γδ axis from the adaptive current observer 210, and also uses the reference vector v _b. Is received from the reference vector calculation means 211a, the outer product of the current error vector e _i corresponding to the deviation between the current detection values i _γ and i _δ and the current estimation values i _{γ #} and i _{δ #} and the reference vector v _b is obtained. The outer product value e _i × v _b is output to the sign calculation means 217 and the adder 220.

Further, the inner product calculation means 211c receives the deviation between the detected current values i _γ and i _δ of the γδ axis and the estimated current values i _{γ #} and i _{δ #} of the γδ axis from the adaptive current observer 210, and receives the reference vector v _b . When received from the reference vector calculation means 211a, the inner product of the current vector e _i corresponding to the deviation between the detected current values i _γ and i _δ and the estimated current values i _{γ #} and i _{δ #} and the reference vector v _b is calculated. Then, the inner product value v _b · e _i is output to the multiplication means 218.
Here, the inner product value v _b · e _i can be given by the following equation (20).

Further, reference numeral calculating means 217 receives the cross product value _{e i} × _{v b} from product computation means 211b, the sign of the cross product value _{e i} × _{v b} is equal positive 1, the sign of the cross product value _{e i} × _{v b} If it is negative, -1 is output to the multiplication means 218, and if the outer product value e _i × v _b is 0, 0 is output.
The multiplying unit 218 multiplies the inner product value v _b · e _i calculated by the inner product calculating unit 211 _c by the code calculated by the code calculating unit 217 and outputs the result to the gain adjusting unit 219.
Next, the gain adjustment unit 219 multiplies the multiplication result calculated by the multiplication unit 218 by the adjustment gain k, and outputs the result to the adder 220.

Next, the adder 220 adds the value obtained by multiplying the multiplication result calculated by the multiplying means 218 by the adjustment gain k and the outer product value calculated by the outer product calculating means 211b, and the angle / speed estimator 216. Output to.
Next, the angle / speed estimator 216 calculates the speed estimated value ω _{r #} (= primary frequency ω ₁ ) and the angle estimated value θ _# based on the output value from the adder 220. Then, the angle / speed estimator 216 uses the primary frequency ω ₁ as the adaptive current observer 210, the subtractor 213 and the reference vector calculation means 211 a, and the angle estimated value θ _# as the rotation two-phase / three-phase coordinate conversion means 205 and the three-phase / Output to the rotating two-phase coordinate transformation means 206.
Here, the primary frequency ω ₁ and the estimated angle value θ _# can be given by the following equation (21).

This makes it possible to calculate the estimated angle value θ _# of the magnetic pole position of the synchronous motor 101 without performing an approximation that holds when the angular error Δθ is small, and to calculate the outer product value when the angular error Δθ of the magnetic pole position is large. Can be compensated for, and even when the angle error Δθ of the magnetic pole position is large, it is possible to ensure the stability of the estimated angle value θ _# of the magnetic pole position.
In the above-described embodiment, in order to obtain the primary frequency ω ₁ and the estimated angle value θ _# , a value obtained by multiplying the multiplication result calculated by the multiplication unit 218 by the adjustment gain k is calculated by the outer product calculation unit 211b. The method of using the addition result with the outer product value thus described has been described. By using the value obtained by multiplying the multiplication result calculated by the multiplication means 218 by the adjustment gain k, the primary frequency ω ₁ and the estimated angle value θ _# are obtained. You may make it ask.

FIG. 7 is a diagram showing a comparison of angular errors between the first embodiment of FIG. 1 and the second embodiment of FIG.
In FIG. 7, the outer product value e _i × v _b calculated by the outer product calculation means 111b in FIG. 1 takes a maximum value when the angle error Δθ is around ± 50 degrees, and decreases as the angle error Δθ approaches ± 90 degrees. To do. For this reason, when the outer product value e _i × v _b decreases, the time until the angle error Δθ converges may increase.

On the other hand, the inner product value v _b · e _i calculated by the inner product calculating means 211c is a function that monotonically increases with respect to the magnitude of the angle error Δθ. Therefore, the outer product value e _i × when the angle error Δθ is large. The decrease in v _b can be compensated, and the output of the adder 220 can take a value proportional to the magnitude of the angle error Δθ up to about ± 75 degrees. Therefore, in the second embodiment in FIG. 6, the response of the position estimation system can be kept constant in a range where the angle error Δθ is larger than in the first embodiment in FIG. 1, and the position estimation system is stabilized. Can do.

It is a block diagram which shows schematic structure of the control apparatus of the synchronous motor which concerns on 1st Embodiment of this invention. It is a figure which shows the calculation method of the outer product calculated by the outer product calculating means of FIG. It is a figure which shows the relationship between the locus | trajectory of a current error vector used in the outer product calculating means of FIG. 1, and an angle error. It is a figure which shows the definition of the current error vector of FIG. It is a figure which shows the relationship between the locus | trajectory of a current error vector used in the outer product calculating means of FIG. 1, and an angle error. It is a block diagram which shows schematic structure of the control apparatus of the synchronous motor which concerns on 2nd Embodiment of this invention. It is a figure which compares and shows the angle error of Embodiment 1 of FIG. 1 and Embodiment 2 of FIG. It is a block diagram which shows schematic structure of the control apparatus of the conventional synchronous motor.

Explanation of symbols

100, 200 Synchronous motor control device 101, 201 Implantable permanent magnet synchronous motor 102, 202 Load 103, 203 Current detection means 104, 204 Power conversion device 105, 205 Rotating two-phase / three-phase coordinate conversion means 106, 206 Three Phase / rotation two-phase coordinate conversion means 107, 207 Current control means 108, 208 Current command value creation means 109, 209 Speed PID adjuster 110, 210 Adaptive current observer 111a, 211a Reference vector calculation means 111b, 211b Outer product calculation means 116, 216 Angle / speed estimator 113, 114, 115, 213, 214, 215 Subtractor 211c Inner product calculation means 217 Sign calculation means 218 Multiplication means 219 Gain adjustment means 220 Adder

Claims (5)

Current detection means for detecting the armature current of the synchronous motor;
An adaptive current observer for estimating an armature current based on the model of the synchronous motor;
A reference vector calculation means for calculating a reference vector serving as a reference for determining whether the angle error of the magnetic pole position of the synchronous motor is positive or negative;
Cross product calculation means for calculating a cross product of a current error vector corresponding to a deviation between a current detection value detected by the current detection means and a current estimation value estimated by the adaptive current observer, and the reference vector;
An angle estimator for calculating an estimated angle value of the magnetic pole position of the synchronous motor based on the outer product value calculated by the outer product calculating means;
A control apparatus for a synchronous motor, comprising: a power converter that performs variable speed control of the synchronous motor based on a voltage command value generated using the estimated angle value. Current detection means for detecting the armature current of the synchronous motor;
An adaptive current observer for estimating an armature current based on the model of the synchronous motor;
A reference vector calculation means for calculating a reference vector serving as a reference for determining whether the angle error of the magnetic pole position of the synchronous motor is positive or negative;
Cross product calculation means for calculating a cross product of a current error vector corresponding to a deviation between a current detection value detected by the current detection means and a current estimation value estimated by the adaptive current observer, and the reference vector;
Code calculating means for calculating the sign of the outer product value calculated by the outer product calculating means;
Monotonically increasing function calculating means for calculating a function that increases monotonously with respect to the magnitude of the angle error of the magnetic pole position of the synchronous motor;
An angle estimator that calculates an estimated angle value of the magnetic pole position of the synchronous motor based on a multiplication result of the function calculated by the monotonically increasing function calculating unit and the code calculated by the code calculating unit;
A control apparatus for a synchronous motor, comprising: a power converter that performs variable speed control of the synchronous motor based on a voltage command value generated using the estimated angle value.   3. The synchronous motor control device according to claim 2, wherein the monotonically increasing function calculating means includes inner product calculating means for calculating an inner product of the current error vector and the reference vector.   The angle estimator is obtained by adding an outer product value calculated by the outer product calculation means and a value obtained by multiplying the inner product value calculated by the inner product calculation means by the code calculated by the code calculation means. 4. The synchronous motor control device according to claim 3, wherein an estimated angle value of the magnetic pole position of the synchronous motor is calculated based on the calculated value.   The reference vector has a magnetic flux axis component value that is proportional to the sum of the integrated value of the inductance difference between the dq axes and the torque axis current and the value that falls within the range of −1 to 1 times the magnetic flux. 5. The torque axis component according to claim 1, wherein the torque axis component has a value proportional to a total value of an inductance difference between dq axes and a magnetic flux axis current and a sum of magnet magnetic flux. Control device for synchronous motor.

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