JP2009284694A - Controller for permanent magnet type synchronous motor - Google Patents

Abstract

A shock is reduced when switching a control method of a permanent magnet type synchronous motor.
A first operation mode in which an electric current, a terminal voltage, and a magnetic flux of a motor are regarded as vectors and an angular velocity of a current command value is controlled to a speed command value, and a magnetic pole position estimated value calculated from the motor current and the terminal voltage And a second operation mode for controlling the motor speed to a speed command value using the estimated speed value, and from the angular speed of the motor current, the terminal voltage, and the current command value when switching from the first to the second operation mode. Means for calculating the expansion induced voltage, means for calculating the magnetic pole position estimation error from the angle of the expansion induced voltage, means for initializing the magnetic pole position estimation value using the magnetic pole position estimation error, and using the angular velocity of the current command value And a means for initializing the terminal voltage command value and the current command value so that the terminal voltage and current do not change suddenly using the magnetic pole position estimation error.
[Selection] Figure 1

Description

  The present invention relates to a control device for a permanent magnet type synchronous motor that does not have a magnetic pole position detector. More specifically, the present invention relates to a motor that smoothly accelerates and decelerates by reducing a shock when switching various control methods according to the speed range of the motor. The present invention relates to a control device for driving.

In order to reduce the cost of a control device for a permanent magnet type synchronous motor, so-called sensorless vector control that operates without using a magnetic pole position detector of a rotor has been put into practical use.
Sensorless vector control realizes high-accuracy torque control and speed control by calculating the magnetic pole position and speed of the rotor from the terminal voltage and current information of the motor, and performing current control based on these. . Examples of sensorless vector control are disclosed in Non-Patent Document 1 and Patent Document 1.

  However, sensorless vector control has a problem in stability at low speed. For this reason, in the low speed range, as described in Patent Document 2, the rotor of the permanent magnet synchronous motor is drawn into the current by controlling the current amplitude to be constant and the current angular velocity to the speed command value. Driving techniques may be applied. Such an operation method is hereinafter referred to as “current draw control”.

On the other hand, Patent Document 3 discloses a technique for switching from current pull-in control to sensorless vector control in a shockless manner when a permanent magnet type synchronous motor having no saliency is accelerated from a stopped state to perform stable speed control in a medium to high speed range. Is disclosed.
In this prior art, the phase of the magnetic flux vector is calculated when switching from current drawing control to sensorless vector control, and the sensorless vector control is started after initializing the estimated magnetic pole position using this.

By the way, since the so-called V / f control, which controls the amplitude of the terminal voltage substantially in proportion to the speed command value and controls the angular speed of the terminal voltage to the speed command value, is easier to calculate than the sensorless vector control, The maximum speed can be increased.
According to the prior art described in Patent Document 4, the terminal voltage and current do not change suddenly when the speed range is expanded by switching between V / f control and sensorless vector control according to speed, and the control method is switched. Thus, the shock at the time of switching is reduced by compensating the voltage command value and the current command value.

Japanese Patent No. 3411878 (paragraphs [0112] to [0159], FIG. 1 and the like) JP 2001-190093 (paragraphs [0002] to [0006], FIG. 7 and the like) Japanese Patent Laying-Open No. 2005-110473 (paragraphs [0008] to [0011], FIG. 1 and the like) Japanese Patent No. 3778618 (paragraphs [0052] to [0070], FIG. 4 etc.) Takashi Aihara, Akio Toba, Takao Yanase, Akihide Mashimo, Kenji Endo, “Sensorless Torque Control of Salient-Pole Synchronous Motor at Zero-Speed Operation”, IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 14, NO.1, JANUARY 1999

In the prior art described in Patent Document 3, in [Formula 2], the inductance value used in the calculation formula of the magnetic flux is approximated by the average value of the d and q axis inductances, and the rotor is embedded with saliency. When applied to a permanent magnet synchronous motor having a magnet structure, an error occurs in the magnetic flux calculation value. Patent Document 3 refers to a switching method from current pull-in control to sensorless vector control, but does not refer to a switching method from sensorless vector control to current pull-in control.
Furthermore, the calculation when switching from V / f control to sensorless vector control described in paragraphs [0052] to [0069] of Patent Document 4 focuses on the relationship between torque and load angle. The processing content is complicated.

  Therefore, the problem to be solved by the present invention is to control a permanent magnet type synchronous motor that realizes smooth acceleration / deceleration operation of a motor in a wide speed range by enabling various control methods to be switched without shock by relatively simple arithmetic processing. To provide an apparatus.

In order to solve the above-described problem, the invention according to claim 1 is directed to a control device for a permanent magnet synchronous motor that does not have a magnetic pole position detector.
Taking the current, terminal voltage, and magnetic flux of the motor as vectors,
A first operation mode for controlling an angular velocity of a current command value of the electric motor to a speed command value;
A second operation mode for controlling the speed of the motor to a speed command value using a rotor magnetic pole position estimated value and a speed estimated value calculated from the current and terminal voltage of the motor;
When switching from the first operation mode to the second operation mode,
Means for calculating an expansion induced voltage from the current of the electric motor, the terminal voltage, and the angular velocity of the current command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expansion induced voltage;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular velocity of the current command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error.
According to this invention, it is possible to switch from the current drawing control as the first operation mode to the sensorless vector control as the second operation mode without shock.

When the invention according to claim 2 is switched from the first operation mode described above to the second operation mode,
Means for calculating an expanded magnetic flux from the electric motor current, terminal voltage, angular velocity of the current command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expanded magnetic flux;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular velocity of the current command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error.
While the magnitude of the expansion induced voltage in claim 1 is proportional to the angular velocity of the rotor, the magnitude of the expansion magnetic flux in claim 2 is constant regardless of the angular velocity, so that the calculation can be made highly accurate even at low speeds. In addition, it is possible to switch from current drawing control to sensorless vector control without shock.

The invention according to claim 3 is a third operation mode in which the amplitude of the voltage command value of the electric motor is controlled substantially in proportion to the speed command value, and the angular velocity of the voltage command value is controlled to the speed command value;
A second operation mode for controlling the speed of the motor to a speed command value using a rotor magnetic pole position estimated value and a speed estimated value calculated from the current and terminal voltage of the motor;
When switching from the third operation mode to the second operation mode,
Means for calculating the expansion induced voltage from the electric current of the motor, the terminal voltage, and the angular velocity of the voltage command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expansion induced voltage;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular speed of the voltage command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the magnetic pole position estimation error calculation value.
According to the present invention, it is possible to switch from V / f control as the third operation mode to sensorless vector control as the second operation mode without shock.

When the invention according to claim 4 is switched from the third operation mode described above to the second operation mode,
Means for calculating an expanded magnetic flux from the electric current of the motor, the terminal voltage, and the angular velocity of the voltage command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expanded magnetic flux;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular speed of the voltage command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error.
According to the present invention, compared with the invention according to claim 3, the calculation can be performed with high accuracy even at low speed, and the V / f control can be switched to the sensorless vector control without shock.

The invention according to claim 5 is the second operation mode of claim 2 or claim 4, wherein
Means for calculating the expansion magnetic flux from the electric current of the motor, the terminal voltage, and the speed estimation value;
Means for calculating the speed estimated value and the magnetic pole position estimated value from the calculated value of the expanded magnetic flux;
With
When switching from the first or third operation mode to the second operation mode, the calculated value of the expanded magnetic flux is initialized so that the calculated value of the expanded magnetic flux does not change suddenly using the calculated value of the magnetic pole position estimation error. It has a means to do.
In the present invention, even when the position / speed estimation calculation in the sensorless vector control as the second operation mode is realized based on the expanded magnetic flux estimated value estimated by the magnetic flux observer, switching can be performed without shock.

According to a sixth aspect of the present invention, in the second operation mode of the second or fourth aspect,
Means for calculating a second expanded magnetic flux from the current of the motor, the terminal voltage, and the estimated speed value;
Means for calculating the speed estimated value and the magnetic pole position estimated value from a second expanded magnetic flux calculated value,
When switching from the first or third operation mode to the second operation mode, there is provided means for initializing the second expansion magnetic flux calculation value using the expansion magnetic flux calculation value obtained in claim 2 or claim 4. It is a thing.
According to the present invention, the arithmetic processing at the time of switching the operation mode can be simplified as compared with the invention according to claim 5.

The invention according to claim 7 is the control device according to any one of claims 1 to 6,
When switching from the first or third operation mode to the second operation mode,
At least means for calculating a torque from the current and terminal voltage of the electric motor and means for initializing a torque command value using the calculated value of the torque.
According to this invention, the shock at the time of operation mode switching can be reduced compared with the invention which concerns on Claims 1-6.

The invention according to claim 8 embodies the torque calculation in the control device according to claim 7.
That is, the invention according to claim 8 is the control device according to any one of claims 1 to 6,
When switching from the first or third operation mode to the second operation mode,
At least means for calculating a torque from the calculated value of the electric current of the electric motor and the expansion induced voltage, and means for initializing a torque command value using the calculated value of the torque.

According to a ninth aspect of the invention, the torque calculation in the control device according to the seventh aspect is embodied in a form different from that of the control device according to the eighth aspect.
That is, the invention according to claim 9 is the control device according to any one of claims 2, 4, 5 or 6,
When switching from the first or third operation mode to the second operation mode,
At least means for calculating a torque from the electric current of the motor and the calculated value of the expansion magnetic flux, and means for initializing a torque command value using the calculated value of the torque.

When the invention according to claim 10 is switched from the second operation mode described above to the first operation mode,
Means for calculating the current command value from the torque command value of the motor;
Means for calculating an angle difference between the current command value and the magnetic pole position estimated value;
Means for initializing an angle of the current command value using an angle difference between the current command value and the magnetic pole position estimation value;
Means for correcting the angular velocity of the current command value so that the angular velocity of the current command value does not change suddenly using the velocity estimation value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using an angular difference between the current command value and the magnetic pole position estimation value;
Means for initializing the current command value so that the current of the motor does not change suddenly using an angular difference between the current command value and the estimated magnetic pole position.
According to this invention, it is possible to switch from sensorless vector control, which is the second operation mode, to current drawing control, which is the first operation mode, without shock.

  ADVANTAGE OF THE INVENTION According to this invention, the sudden change of the terminal voltage or electric current at the time of switching various control systems according to the driving speed range of an electric motor can be prevented, and a shock can be reduced. Thereby, it is possible to realize a smooth acceleration / deceleration operation of the permanent magnet type synchronous motor by expanding the speed range.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a first embodiment of the present invention corresponding to claims 1 and 8.
This first embodiment is for switching from current drawing control of Patent Document 2 to sensorless vector control using the extended induced voltage of Non-Patent Document 1 without shock.

Permanent magnet type synchronous motors can achieve high-accuracy torque control by performing current control according to the d-axis of the rotor (the direction of the magnetic pole of the rotor) and the q-axis advanced 90 degrees from this d-axis. It is. However, since the d and q axes cannot be directly detected without the magnetic pole position detector, the γ and δ axes of the orthogonal rotation coordinate system that rotates at the electrical angular velocity ω ₁ corresponding to the d and q axes are on the controller side. The control calculation is performed by estimating.
The definitions of the d, q axis and the γ, δ axes are shown in FIG. The N-pole direction of the rotor of the permanent magnet synchronous motor is the d-axis, the 90 ° advance direction from the d-axis is the q-axis, the estimated axis corresponding to the d-axis is the γ-axis, and the 90 ° advance direction from the γ-axis is δ Define as axis.
However, in FIG.
ω _r : electrical angular velocity of d and q axes, ω ₁ : electrical angular velocity of γ and δ axes (= speed estimation value), θ _err : angles of γ and δ axes with respect to d and q axes (angle difference or magnetic pole position estimation error) (Also called)
And

First, the configuration of the main circuit in FIG. 1 is as follows.
Reference numeral 50 denotes a three-phase AC power source, and the rectifier circuit 60 rectifies the three-phase AC voltage of the power source 50 and converts it into a DC voltage. This DC voltage is supplied to a power converter 70 composed of a PWM inverter, and is converted into a predetermined three-phase AC voltage for driving the electric motor 80.

Next, the operation at the time of current drawing control in FIG. 1 will be described together with the configuration of the control device.
Set the input of the changeover switch 23 to the "S1", gamma, controls the angular velocity omega ₁ of the δ-axis to the speed command value omega ^*. The electrical angle calculator 24 integrates the angular velocities ω ₁ of the γ and δ axes to calculate the angle θ ₁ of the γ and δ axes.
Further, the inputs of the changeover switches 21a and 21b are set to “S1”, and the first current command calculator 41 controls the γ and δ-axis current command values i _γ ^* and i _δ ^* as shown in Equation 1.

The low-pass filters 22a and 22b calculate the low-frequency components i _γf ^* and i _δf ^* of the γ and δ-axis current command values i _γ ^* and i _δ ^* .
The current coordinate converter 14 converts the phase current detection values i _u and i _w detected by the u-phase current detector 11u and the w-phase current detector 11w, respectively, into the γ and δ axes based on the angle θ ₁ of the γ and δ axes. Coordinates are converted to current detection values i _γ and i _δ .
A deviation between the γ-axis current command value i _γf ^* and the detected γ-axis current value i _γ is calculated by the subtractor 19a, and the deviation is amplified by the current regulator 20 to calculate the γ-axis voltage command value v _γ ^* . On the other hand, the deviation between the δ-axis current command value i _δf ^* and the δ-axis current detection value i _δ is calculated by the subtractor 19b, and this deviation is amplified by the current regulator 20 to calculate the δ-axis voltage command value v _δ ^* . To do.
These voltage command values v _γ ^* and v _δ ^* are converted into phase voltage command values v _u ^* , v _v ^* and v _w ^* based on the angle θ ₁ of the γ and δ axes by the voltage coordinate converter 15.

The PWM circuit 13 generates a gate signal from the phase voltage command values v _u ^* , v _v ^* , v _w ^* and the input voltage E _dc of the power converter 70 detected by the voltage detector 12. The power converter 70 controls the internal semiconductor switching element based on the gate signal, thereby controlling the terminal voltage of the permanent magnet type synchronous motor 80 to the phase voltage command values v _u ^* , v _v ^* , v _w ^* . To do.
By these controls, a current vector having an amplitude equal to I _γ ^* and an angular velocity equal to the speed command value ω ^* is generated and the rotor is drawn into the current vector, and the rotor angular velocity ω _r is controlled to the speed command value ω ^*. The

Next, the operation at the time of sensorless vector control will be described. Note that the description will focus on parts different from the current pull-in control, and a description of the overlapping parts will be omitted.
The deviation between the speed command value ω ^* and the estimated speed value ω ₁ is calculated by the subtractor 16, and the deviation is amplified by the speed regulator 17 to calculate the torque command value τ ^* .
The inputs of the changeover switches 21a and 21b are set to “S2”, and the output of the second current command calculator 18 is set to the γ and δ axis current command values i _γ ^* and i _δ ^* . Based on the torque command value τ ^* , the current command calculator 18 calculates the γ and δ-axis current command values i _γ ^* and i _δ ^* under the condition that the torque / current is maximized.

The operations of the low-pass filters 22a and 22b, the subtractors 19a and 19b, the current adjuster 20, the current coordinate converter 14 and the voltage coordinate converter 15 are the same as those in the case of the current pull-in control. _gamma, i _[delta] is the command value _i γ ^_*, i δ ^* in the matching manner the phase voltage command values ^{_{v u *, v v *,}} v w * is controlled.
On the other hand, the expanded induced voltage calculator 31 receives γ, δ-axis voltage command values v _γ ^* , v _δ ^* , γ, δ-axis current detection values i _γ , i _δ, and a speed estimation value ω ₁ . The expansion induced voltage calculator 31 calculates the expansion induced voltage using Equation 2.

FIG. 8 is a vector diagram showing the relationship between the expansion induced voltage and the angle difference. The expansion induced voltage E _ex is generated in the q-axis direction that is orthogonal to the rotor. As is apparent from FIG. 8, the angle _δEex of the extended induced voltage observed on the γ and δ axes is equal to the angle difference (= magnetic pole position estimation error) θ _err between the d and q axes and the γ and δ axes. Thereby, the angle difference θ _err can be detected from the angle δ _Eex of the expansion induced voltage.
That is, the angle calculator 32 in FIG. 1, the angle [delta] _Eex expansion induced voltage is calculated by Equation 3, the angle [delta] _Eex, the magnetic pole position estimation error calculation value theta _Errest as shown in Equation 4.

The changeover switch 23 in FIG. 1 sets the input to “S2”, and the speed estimator 33 receives the estimated speed value ω ₁ (of the γ and δ axes) by the PI controller that receives the magnetic pole position estimation error calculation value θ _errest . (Equal to the angular velocity) is calculated by Equation 5. The estimated speed value ω ₁ is input to the electrical angle calculator 24 and the extended induced voltage calculator 31.

The electrical angle calculator 24 calculates the magnetic pole position estimated value θ ₁ (equal to the angles of the γ and δ axes) by integrating the speed estimated value ω ₁ .
The above-described extended induced voltage calculator 31, angle calculator 32, speed estimator 33, and electrical angle calculator 24 can converge the angle difference θ _err between the γ and δ axes and the d and q axes to zero, This makes it possible to accurately estimate the magnetic pole position θ ₁ and the speed ω ₁ . Thereby, the torque and speed of the electric motor 80 can be accurately controlled.

Next, the principle of the switching process from the current drawing control as the first operation mode to the sensorless vector control as the second operation mode will be described with reference to the vector diagram of FIG.
In the current drawing control shown on the left side of FIG. 9, the angle difference θ _err between the d and q axes and the γ and δ axes is an increasing function of the load torque. On the other hand, in the sensorless vector control on the right side of FIG. 9, the angle difference θ _err between the d and q axes and the γ and δ axes is controlled to be substantially zero.
Therefore, the current in the case where the pull-in control switches to the sensorless vector control, initializes the magnetic pole position estimation value theta ₁ to the angle of the d-axis, this time in the voltage command vector v ^* and the low-pass filter 22a, 22b current command vector i of the output of the Initialize so that _f ^* is continuous before and after switching (so as not to change suddenly). Further, the torque command value τ ^* is initialized with the torque before switching, and the current command vector i ^* is calculated to a value for outputting the torque before switching.

Next, calculation processing when switching from current drawing control to sensorless vector control according to the above principle will be described.
In the state in which the current drawing control is performed, the expansion induced voltage calculator 31 in FIG. 1 calculates the expansion induced voltage calculation values E _exγ and E _exδ , and the angle calculator 32 calculates the angle δ _Eex of the expansion induced voltage.
Here, the torque calculator 111 calculates the torque calculation value τ _calc using the expanded induced voltage calculation values E _exγ and E _exδ and the γ, δ-axis current detection values i _γ and i _δ and the estimated speed value ω _1. 6 is obtained.

In the speed regulator 17 to which the torque calculation value τ _calc is input, the torque command value τ ^* as the output is initialized to the torque calculation value τ _calc .
Further, the integrator output of the speed estimator 33 is initialized to γ and δ-axis speed ω _1, and the output θ ₁ of the electrical angle calculator 24 is initialized by Equation 7.

As the electrical angle correction value δ _comp in Formula 7, the angle δ _Eex (magnetic pole position estimation error calculation value θ _errest ) of the extended induced voltage is used according to Formula 8.

As the angle θ ₁ of the γ and δ axes is corrected by δ _comp by Equation 7, the current command values i _γf ^* and i _δf ^* that are the outputs of the low-pass filters 22 a and 22 b and the output of the current regulator 20 A certain γ, δ-axis voltage command value v _γ ^* , v _δ ^* is _converted into a magnetic pole position estimation error calculation value θ _errest and a previous value i _{γ (n−1)} of the γ, δ-axis current detection value before switching to sensorless vector control. ₎ , I _{δ (n−1)} , and previous values v _{γ (n−1)} ^* and v _{δ (n−1)} ^* of the γ and δ-axis voltage command values, respectively, by Equations 9 and 10, respectively. initialize.

When switching to sensorless vector control by controlling the power converter 70 in accordance with the current command values i _γf ^* and i _δf ^* and γ and δ-axis voltage command values v _γ ^* and v _δ ^* obtained by Expressions 9 and 10. A sudden change in the current and terminal voltage of the motor 80 can be prevented, and a shock can be eliminated.

Next, a second embodiment of the present invention corresponding to claims 2 and 9 will be described. FIG. 2 is a block diagram showing the second embodiment.
In the second embodiment, the electrical angle correction value δ _comp in the first embodiment is calculated by using an extended magnetic flux so that it can be calculated with high accuracy even at a low speed. This block diagram will be described with a focus on differences from FIG.

First, the operation when switching from the current drawing control as the first operation mode to the sensorless vector control as the second operation mode will be described.
2, extended flux calculator 34, gamma, [delta] axis extended induced voltage calculation value _{E exγ, γ} from _{E exδ, δ-axis} expansion flux operation value [psi _Exganma, the [psi _Exderuta computed using Equation 11.

FIG. 10 is a vector diagram showing the relationship between the expanded magnetic flux and the magnetic pole position estimation error. As shown in FIG. 10, the expanded magnetic flux vector Ψ _ex and the expanded induced voltage vector E _ex are orthogonal to each other, and the expanded magnetic flux vector Ψ _ex is generated in the d-axis direction. Therefore, the angle difference θ _err between the d and q axes and the γ and δ axes can be calculated from the angle _{δΨex of the} expanded magnetic flux.
Angle calculator 35 in FIG. 2 gamma, [delta] axis extended flux operation value _Ψ exγ, Ψ angles [delta] _Pusaiex extended flux calculated by Equation 12 from _Exderuta, electrical angle correction value as Equation 13 from this angle _δ Ψex δ _comp .

Using the electrical angle correction value δ _comp shown in Expression 13, the electrical angle calculator 24, the low-pass filters 22a and 22b, and the current regulator 20 are initialized as in the first embodiment.
Further, the torque calculator 112 _obtains the torque calculation value τ _calc using Equation 14 using the γ and δ-axis expanded magnetic flux calculation values ψ _exγ and ψ _exδ and the γ and δ-axis current detection values i _γ and i _δ .

Furthermore, the speed regulator 17 initializes the torque command value τ ^* , which is the output thereof, to a torque calculation value τ _calc calculated by Equation 14.
Further, the integrator output of the speed estimator 33 is initialized to the γ and δ axis speed ω ₁ . Subsequent operations are the same as those in the first embodiment.
Also in this embodiment, it is possible to prevent a shock when switching to sensorless vector control by preventing sudden changes in the current and terminal voltage of the motor 80.

Next, a third embodiment of the present invention corresponding to claims 2, 5 and 9 will be described. FIG. 3 is a block diagram showing the third embodiment. In the third embodiment, the position / velocity estimation calculation in the first embodiment is performed based on the expanded magnetic flux estimated value estimated by the magnetic flux observer. It is designed to enable stable operation even at low speeds.
Hereinafter, in FIG. 3, a description will be given centering on points different from FIG.

First, the position / speed estimation calculation at the time of sensorless vector control will be described.
The magnetic flux observer 36 calculates the expanded magnetic flux estimated values Ψ _exγest , Ψ _exδest from the γ, δ-axis voltage command values v _γ ^* , v _δ ^* , γ, δ-axis current detection values i _γ , i _δ and the speed estimated value ω _1. Calculate.
Here, the magnetic flux observer 36 is configured, for example, as described in Japanese Patent Application No. 2008-130791 which is a prior application by the present applicant.
That is, the state equations of γ and δ-axis currents i _γ and i _δ including the expanded magnetic flux are expressed by Equations 15 and 16.

In Expressions 15 and 16, d and q-axis current differential values pi _d and pi _q are approximated to zero, and the estimated speed value ω ₁ is approximated to the actual speed value ω _r , and γ, By approximating that the δ-axis terminal voltages v _γ and v _δ can be controlled to γ and δ-axis voltage command values v _γ ^* and v _δ ^* , respectively, the magnetic flux observer is configured by Equations 17 and 18.

The first line on the right side of Equation 17 physically corresponds to the γ and δ axis current differential values, and among these, the calculation result in parentheses corresponds to the transient voltage. That is, the first line on the right side of Equation 17 specifically includes the armature resistance voltage drop, the armature reaction voltage drop, and the armature resistance voltage drop and the armature reaction voltage drop from the γ and δ axis voltage command values (here, equal to the γ and δ axis voltage detection values). extended electromotive force by subtracting the calculated transient voltage, the transient voltage obtained by multiplying the inverse of d-axis inductance L _d gamma, and calculates the δ-axis current differential value.
The second line on the right side of Equation 17 corresponds to a current correction value that is calculated by amplifying the deviation between the current estimated value i _γδest and the current detection value i _γδ. The current estimated value i _γδest is calculated based on the addition result of the δ-axis current differential value and the current correction value, and the deviation between the current estimated value i _γδest and the detected current value i _γδ is amplified by Equation 18. This indicates that the expanded magnetic flux estimated value Ψ _exγδest is calculated.

Then, the angle calculator 37 in FIG. 3, extend the magnetic flux estimation value [psi _Exganmaest, the angle [delta] _Pusaiexest extended flux estimate from [psi _Exderutaest computed using Equation 19.

The magnetic pole position estimation error calculation value θ _errest which is an input of the speed estimator 33 is _obtained from the angle δ _Ψexest of the expanded magnetic flux estimation value by Expression 20.

The speed estimator 33 calculates the speed estimated value ω ₁ by a PI controller that receives the magnetic pole position estimation error calculated value θ _errest , and the electrical angle calculator 24 integrates the speed estimated value ω ₁ to estimate the magnetic pole position estimated value. Calculate θ ₁ .

Next, an initialization process when switching from the current drawing control as the first operation mode to the sensorless vector control as the second operation mode will be described.
As described above, the magnetic flux observer 36 calculates the expanded magnetic flux estimated values Ψ _exγest and Ψ _exδest , and the angle calculator 37 calculates the angle δ _Ψexest of the expanded magnetic flux estimated value.
The electrical angle correction value δ _comp is calculated by Equation 21 from the angle δ _ψexist of the expanded magnetic flux estimated value.

The initialization processing of the electrical angle calculator 24, the low-pass filters 22a and 22b, and the current regulator 20 is the same as in the second embodiment.
Further, the output of the magnetic flux observer 36 is initialized by Equation 22.

The torque calculator 112 uses the γ and δ-axis expanded magnetic flux estimated values ψ _exγest and ψ _exδest and the γ and δ-axis current detection values i _γ and i _δ to calculate a torque calculation value τ _calc according to the following equation according to Equation 14: Ask for.
τ _calc = Ψ _exγest i _δ −Ψ _exδest i _γ
Then, the torque command value τ ^* , which is the output of the speed regulator 17, is initialized to the torque calculation value _τcalc . Further, the integrator output of the speed estimator 33 is initialized to the γ and δ axis speed ω ₁ . Subsequent operations are the same as those in the first embodiment.
Also in the present embodiment, it is possible to prevent a sudden change in the current and terminal voltage of the electric motor 80 and eliminate the shock when switching to the sensorless vector control.

Next, a fourth embodiment of the present invention corresponding to claims 2, 6 and 9 will be described. FIG. 4 is a block diagram showing the fourth embodiment.
In the fourth embodiment, the amount of calculation is reduced by performing the initialization process of each unit in the third embodiment by directly calculating the extended magnetic flux from the extended induced voltage without using the magnetic flux observer. In the following, description will be made mainly on the points different from FIG. 3 in FIG.

The switching process from the current drawing control that is the first operation mode to the sensorless vector control that is the second operation mode is as follows.
In FIG. 4, as in the second embodiment, the expansion induced voltage calculator 31 calculates the expansion induced voltage calculation values E _exγ and E _exδ , and the expansion flux calculator 34 calculates the expansion flux calculation values Ψ _exγ and Ψ _exδ , The angle calculator 35 calculates the expanded magnetic flux angle δ _Ψex . Further, the electrical angle correction value δ _comp is calculated from the expanded magnetic flux angle δ _{ψex according} to Equation 13.

The initialization process of the torque calculator 112, the electrical angle calculator 24, the low-pass filters 22a and 22b, and the current regulator 20 when switching from the current pull-in control to the sensorless vector control is the same as in the second embodiment.
The outputs Ψ _exγest , Ψ _exδest of the magnetic flux observer 36 are initialized by Expression 22 as in the third embodiment.

  Next, a fifth embodiment of the present invention corresponding to claims 3 and 8 will be described. In the fifth embodiment, the V / f control as the third operation mode is switched to the sensorless vector control using the extended induced voltage as the second operation mode without shock.

FIG. 5 is a block diagram showing the fifth embodiment. First, the operation during V / f control will be described.
In FIG. 5, the input of the changeover switch 26 is set to “S3”, and the angular velocity ω ₁ of the γ and δ axes is controlled to the velocity command value ω ^* . The electrical angle calculator 24 integrates the angular velocities ω ₁ of the γ and δ axes to calculate the angle θ ₁ of the γ and δ axes.
Further, the inputs of the changeover switches 25a and 25b are set to “S3”, and the f / V converter 42 sets the γ-axis voltage command value v _γ ^* to zero and the δ-axis voltage command value v _δ ^* to the speed command value ω ^*. Is controlled almost in proportion to

On the other hand, when the sensor-less vector control, set to set the input of the changeover switch 26 to "S2", gamma, calculated by the angular velocity omega ₁ speed estimator 33 of δ-axis, the change-over switch 25a, the input 25b to "S2" Then, the current regulator 20 controls the γ and δ-axis voltage command values v _γ ^* and v _δ ^* . The detailed operation is the same as that of the first embodiment shown in FIG.

Next, the principle of switching processing from V / f control to sensorless vector control will be described with reference to the vector diagram of FIG.
As shown on the left side of FIG. 11, in the case of V / f control, the voltage command vector v ^* is controlled in the δ-axis direction, and the angle difference θ _err between the d, q-axis and the γ, δ-axis is an increase function of the load torque. It is. On the other hand, in the sensorless vector control shown on the right side of FIG. 11, the angle difference θ _err between the d and q axes and the γ and δ axes is controlled to be substantially zero.
Therefore, when switching from the V / f control to the sensor-less vector control, it initializes the magnetic pole position estimation value theta ₁ to the angle of the d-axis is initialized so as to continue before and after the voltage command vector v ^* switched at this time. Further, the torque command value τ ^* is initialized with the torque before switching, and the current command vector i ^* is calculated to a value for outputting the torque before switching. The current command vector i _f ^* output from the low-pass filters 22a and 22b is initialized with the current value before switching.

Next, calculation processing when switching from V / f control to sensorless vector control will be described.
In FIG. 5, the expansion induced voltage calculator 31 calculates the expansion induced voltage calculation values E _exγ and E _exδ , and the angle calculator 32 calculates the angle δ _Eex of the expansion induced voltage using Equation 3.
Similar to the first embodiment, the output of the speed regulator 17 is initialized by the torque computation value τ _calc obtained by the torque calculator 111, and the electrical angle calculator 24, the low-pass filters 22a and 22b, and the current regulator 20 are Initialization is performed using the electrical angle correction value δ _comp calculated from the angle δ _Eex of the extended induced voltage. The initialization method is the same as in the first embodiment.
Also in the fifth embodiment, it is possible to eliminate a shock when switching to sensorless vector control by preventing sudden changes in the current and terminal voltage of the electric motor 80.

In addition, instead of the expansion induced voltage calculator 31 in FIG. 5, as shown in FIG. 3, the magnetic flux observer 36 and the angle calculator 37 are used to obtain the expanded magnetic flux angle δ _Ψexest and the position estimation error calculation value θ _errest , This may be used as the electrical angle correction value δ _comp to initialize the electrical angle calculator 24, the low-pass filters 22a and 22b, and the current regulator 20 when switching to sensorless vector control.
This idea corresponds to the invention according to claim 4.

Finally, a sixth embodiment of the present invention corresponding to claim 10 will be described. FIG. 6 shows a block diagram of the sixth embodiment.
In the sixth embodiment, the sensorless vector control using the extended induced voltage which is the second operation mode is switched to the current drawing control which is the first operation mode without shock.

First, the principle of switching processing from sensorless vector control to current drawing control will be described with reference to the vector diagram of FIG.
In the case of the sensorless vector control shown on the left side of FIG. 12, the current command vector i ^* is controlled so that the torque / current is maximized. However, in the case of the current pull-in control on the right side of FIG. The control calculation is performed with constant control, defining the direction of the current command vector i ^* as the γ-axis.
Therefore, when switching from sensorless vector control to current pull-in control, a current command value is calculated so that the torque does not change before and after switching, and an angle difference δ _i between the d-axis and the current command vector i ^* is calculated. Using the difference δ _i , the angle θ ₁ of the γ and δ axes is initialized. At the same time, the voltage command vector v ^* and the current command vector _if ^* output from the low-pass filters 22a and 22b are initialized so as to be continuous before and after switching.

Next, calculation processing when switching from sensorless vector control to current drawing control will be described.
The current command initial value calculator 121 in FIG. 6 controls the torque to the command value τ ^* when the current command value is controlled to the amplitude I _γ ^* . The q-axis current command value i _q1 ^* on the d and q axes is approximately calculated by Equation 23.

On the other hand, the d-axis current command value i _d1 ^* is calculated by Equation 24 from the current command value amplitude I _γ ^* and the q-axis current command value i _q1 ^* .

The angle difference δ _i between the d-axis and the current command vector i ^* is calculated by Equation 25.

The electrical angle correction value δ _comp is expressed by Equation 26 using the angle difference δ _i .

The electrical angle calculator 24, the low-pass filters 22a and 22b, and the current regulator 20 are initialized using the electrical angle correction value δ _comp . This initialization method is the same as in the first embodiment.
The angular velocity compensator 123 calculates the angular velocity compensation value ω _1comp from the start of the current drawing control so that the angular velocity ω ₁ of the γ and δ axes does not change suddenly when switching, and the adder 124 calculates the velocity command value ω ^* and the angular velocity compensation value ω. γ by adding the _1Comp, calculates an angular velocity omega ₁ of the δ-axis.
FIG. 13 shows the operating principle of the angular velocity compensator 123. The initial value of the angular velocity compensation value ω _1comp is a deviation between the estimated speed value ω ₁ and the speed command value ω ^* calculated by the subtractor 122 immediately before switching to the current pull-in control, and then the angular velocity compensation value ω _1comp is set to a predetermined value. The rate of change is reduced to zero.
According to the sixth embodiment, it is possible to prevent a shock by preventing a sudden change in the current and terminal voltage of the electric motor 80 when switching to the current drawing control.

1 is a block diagram showing a first embodiment of the present invention. It is a block diagram which shows 2nd Embodiment of this invention. It is a block diagram which shows 3rd Embodiment of this invention. It is a block diagram which shows 4th Embodiment of this invention. It is a block diagram which shows 5th Embodiment of this invention. It is a block diagram which shows 6th Embodiment of this invention. It is a figure which shows the definition of (gamma) and (delta) axis | shaft. It is a vector diagram which shows the relationship between an expansion induced voltage and an angle difference (magnetic pole position estimation error). It is a vector diagram which shows the principle of the switching process from electric current drawing control to sensorless vector control. It is a figure which shows the relationship between an extended magnetic flux and a magnetic pole position estimation error. It is a vector diagram which shows the principle of the switching process from V / f control to sensorless vector control. It is a vector diagram which shows the principle of the switching process from sensorless vector control to electric current drawing control. It is a figure which shows the principle of operation of an angle compensator.

Explanation of symbols

50 three-phase AC power supply 60 rectifier circuit 70 power converter 80 permanent magnet synchronous motor 11u u-phase current detector 11w w-phase current detector 12 voltage detector 13 PWM circuit 14 current coordinate converter 15 voltage coordinate converter 16 subtractor 17 Speed command calculator 18 Current command calculator 19a, 19b Subtractor 20 Current regulator 21a, 21b Changeover switch 22a, 22b Low pass filter 23 Changeover switch 24 Electric angle calculator 25a, 25b Changeover switch 26 Changeover switch 31 Expansion induced voltage calculation Unit 32 Angle calculator 33 Speed estimator 34 Expanded magnetic flux calculator 35 Angle calculator 36 Magnetic flux observer 37 Angle calculator 41 Current command calculator 42 f / V converters 111 and 112 Torque calculator 121 Current command initial value calculator 122 Subtractor 123 Angular velocity compensator 124 Adder

Claims (10)

In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
Taking the current, terminal voltage, and magnetic flux of the motor as vectors,
A first operation mode for controlling an angular velocity of a current command value of the electric motor to a speed command value;
A second operation mode for controlling the speed of the motor to a speed command value using a rotor magnetic pole position estimated value and a speed estimated value calculated from the current and terminal voltage of the motor;
When switching from the first operation mode to the second operation mode,
Means for calculating the expansion induced voltage from the electric motor current, terminal voltage, angular velocity of the current command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expansion induced voltage;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular velocity of the current command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
A control device for a permanent magnet type synchronous motor. In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
Taking the current, terminal voltage, and magnetic flux of the motor as vectors,
A first operation mode for controlling an angular velocity of a current command value of the electric motor to a speed command value;
A second operation mode for controlling the speed of the motor to a speed command value using a rotor magnetic pole position estimated value and a speed estimated value calculated from the current and terminal voltage of the motor;
When switching from the first operation mode to the second operation mode,
Means for calculating an expanded magnetic flux from the electric motor current, terminal voltage, angular velocity of the current command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expanded magnetic flux;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular velocity of the current command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
A control device for a permanent magnet type synchronous motor. In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
Taking the current, terminal voltage, and magnetic flux of the motor as vectors,
A third operation mode in which the amplitude of the voltage command value of the electric motor is controlled substantially in proportion to the speed command value, and the angular speed of the voltage command value is controlled to the speed command value;
A second operation mode for controlling the speed of the motor to a speed command value using a rotor magnetic pole position estimated value and a speed estimated value calculated from the current and terminal voltage of the motor;
When switching from the third operation mode to the second operation mode,
Means for calculating the expansion induced voltage from the electric current of the motor, the terminal voltage, and the angular velocity of the voltage command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expansion induced voltage;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular speed of the voltage command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the magnetic pole position estimation error calculation value;
A control device for a permanent magnet type synchronous motor. In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
Taking the current, terminal voltage, and magnetic flux of the motor as vectors,
A third operation mode in which the amplitude of the voltage command value of the electric motor is controlled substantially in proportion to the speed command value, and the angular speed of the voltage command value is controlled to the speed command value;
A second operation mode for controlling the speed of the motor to a speed command value using a rotor magnetic pole position estimated value and a speed estimated value calculated from the current and terminal voltage of the motor;
When switching from the third operation mode to the second operation mode,
Means for calculating an expanded magnetic flux from the electric current of the motor, the terminal voltage, and the angular velocity of the voltage command value;
Means for calculating a magnetic pole position estimation error from the angle of the calculated value of the expanded magnetic flux;
Means for initializing the magnetic pole position estimation value using the calculated value of the magnetic pole position estimation error;
Means for initializing the speed estimate using an angular speed of the voltage command value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
Means for initializing the current command value so that the electric current of the motor does not change suddenly using the calculated value of the magnetic pole position estimation error;
A control device for a permanent magnet type synchronous motor. A control device according to claim 2 or claim 4, wherein
In the second operation mode,
Means for calculating the expansion magnetic flux from the electric current of the motor, the terminal voltage, and the speed estimation value;
Means for calculating the speed estimated value and the magnetic pole position estimated value from the calculated value of the expanded magnetic flux;
With
When switching from the first or third operation mode to the second operation mode, the calculated value of the expanded magnetic flux is initialized so that the calculated value of the expanded magnetic flux does not change suddenly using the calculated value of the magnetic pole position estimation error. A control device for a permanent magnet type synchronous motor, characterized by comprising: A control device according to claim 2 or claim 4, wherein
In the second operation mode,
Means for calculating a second expanded magnetic flux from the current of the motor, the terminal voltage, and the estimated speed value;
Means for calculating the speed estimated value and the magnetic pole position estimated value from a second expanded magnetic flux calculated value,
When switching from the first or third operation mode to the second operation mode, there is provided means for initializing the second expansion magnetic flux calculation value using the expansion magnetic flux calculation value obtained in claim 2 or claim 4. A control device for a permanent magnet type synchronous motor, characterized in that In the control device according to any one of claims 1 to 6,
When switching from the first or third operation mode to the second operation mode,
Means for calculating torque from at least the current and terminal voltage of the motor, and means for initializing a torque command value using the calculated value of the torque;
A control device for a permanent magnet type synchronous motor. In the control device according to any one of claims 1 to 6,
When switching from the first or third operation mode to the second operation mode,
Means for calculating torque from at least the electric current of the motor and the calculated value of the expansion induced voltage, and means for initializing a torque command value using the calculated value of the torque;
A control device for a permanent magnet type synchronous motor. The control device according to any one of claims 2, 4, 5 and 6,
When switching from the first or third operation mode to the second operation mode,
Means for calculating torque from at least the electric current of the electric motor and the calculated value of the expansion magnetic flux, and means for initializing a torque command value using the calculated value of the torque;
A control device for a permanent magnet type synchronous motor. In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
Taking the current, terminal voltage, and magnetic flux of the motor as vectors,
A first operation mode for controlling an angular velocity of a current command value of the electric motor to a speed command value;
A second operation mode for controlling the speed of the motor to a speed command value using a rotor magnetic pole position estimated value and a speed estimated value calculated from the current and terminal voltage of the motor;
When switching from the second operation mode to the first operation mode,
Means for calculating the current command value from the torque command value of the motor;
Means for calculating an angle difference between the current command value and the magnetic pole position estimated value;
Means for initializing an angle of the current command value using an angle difference between the current command value and the magnetic pole position estimation value;
Means for correcting the angular velocity of the current command value so that the angular velocity of the current command value does not change suddenly using the velocity estimation value;
Means for initializing a terminal voltage command value so that the terminal voltage of the motor does not change suddenly using an angular difference between the current command value and the magnetic pole position estimation value;
Means for initializing the current command value so that the current of the motor does not change suddenly using an angular difference between the current command value and the magnetic pole position estimation value;
A control device for a permanent magnet type synchronous motor.

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