JP2008193796A - Controller of permanent magnet motor, control method of permanent magnet motor, and module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, in position sensorless control, the calculation for estimating an axial error Δθ(θc<SP>*</SP>-θ), which is a deviation between a rotation phase command value θc<SP>*</SP>of a control reference and a rotation phase value θ of a permanent magnet motor, is performed with motor constant and current values of d-axis and q-axis, but when a current of d-axis is generated other than zero, "an estimation error Δθe(Δθ-Δθc)" occurs to an estimated calculation value Δθc of the axial error if a setting error (R-R<SP>*</SP>) of a resistor is present, so that it becomes difficult to realize current minimization with the same torque at low-speed side. <P>SOLUTION: By varying an inductance value equivalent to q-axis used for a vector control calculation and an axial-error estimated calculation, inductance is searched which decreases a motor current close to a minimum point with the same torque. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device, a control method, and a module for a permanent magnet motor.

  A highly efficient control operation method for a permanent magnet motor is disclosed in Japanese Patent Application Laid-Open No. 2000-209886, in which a motor rotor position detection signal and a current on the power source side are detected and a predetermined time interval between the previous time and the current time. The current value and the energization phase setting value are compared, a new energization phase is set based on the comparison result, and a method for actively searching for the optimum energization phase and realizing the highest efficiency operation is described. Yes.

JP 2000-209886 A

  A position sensor is attached to the permanent magnet motor, and the detected values of position and frequency are used to optimize the d-axis current Id and the q-axis current Iq to the required torque as described in JP-A-2000-209886. By controlling with the current phase, highly efficient control operation can be realized.

However, when applied to “position sensorless control” in which the position sensor of the motor is omitted, if there is a resistance setting error (R−R ^* ), the optimum current phase cannot be maintained, and high-efficiency operation cannot be realized. .

In the position sensorless control, the axis error Δθ (θc ^* −θ), which is the deviation between the control reference rotational phase command value θc ^* and the rotational phase value θ of the permanent magnet motor, is detected, and the motor constant and d-axis and q-axis current detection. Estimate using the value. Using this calculated value Δθc, a frequency calculated value ω ₁ is calculated, and further a rotational phase command value θc ^* is created.

However, if the d-axis current command value Id ^* or the shaft error command value Δθc ^* is generated at a value other than “zero”, an estimation error occurs in Δθc if a resistance setting error (R−R ^* ) exists. The optimum current phase cannot be maintained.

  There has been a problem that the motor current settles at a value deviating from the true current minimum point.

An object of the present invention is to provide a control device for a permanent magnet motor that can automatically realize a high-efficiency operation even when a setting error (RR ^* ) or other control constant exists. is there.

  The inductance value used for the vector control calculation and the axis error estimation calculation is changed to search for the inductance value at which the detected value of the motor current is the minimum, and the inductance value obtained by the search is calculated as the vector control calculation or This is to set the axis error estimation calculation.

It is possible to provide a control device for a permanent magnet motor that can automatically realize high-efficiency operation even when a setting error exists in the resistance setting error (R−R ^* ) and other control constants.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 1 shows a configuration example of a “highly efficient speed controller for a permanent magnet motor” according to an embodiment of the present invention.

  The permanent magnet motor 1 outputs a motor torque obtained by combining a torque component due to the magnetic flux of the permanent magnet and a torque component due to the inductance of the armature winding.

The power converter 2 outputs a voltage proportional to the three-phase AC voltage command values Vu ^* , Vv ^* , Vw ^* , and varies the output voltage and the rotational speed of the permanent magnet motor 1.

  The current detector 3 detects the three-phase AC currents Iu, Iv, and Iw of the permanent magnet motor 1.

The coordinate converter 4 detects the detected current values Idc, Iqc of the d-axis and the q-axis from the detected values Iuc, Ivc, Iwc of the three-phase alternating currents Iu, Iv, Iw and the rotational phase command value θc ^{* of the} power converter 2. Is output.

The axis error estimation calculation unit 5 calculates the rotation phase command value of the power converter 2 based on the voltage command values Vdc ^* and Vqc ^* , the inductance value L ^* , the frequency calculation value ω ₁ , the current detection values Idc and Iqc, and the motor constant. An estimation calculation of an axis error that is a deviation between θc ^* and the motor phase value θ is performed, and a calculation value Δθc is output.

The frequency calculation unit 6 outputs a frequency calculation value ω ₁ from the deviation between the axis error command value Δθc ^* which is “zero” and the axis error calculation value Δθc.

The phase calculation unit 7 integrates the frequency calculation value ω ₁ and outputs the rotation phase command value θc ^* to the coordinate conversion units 4 and 12.

The speed control calculation unit 8 outputs the q-axis current command value Iq ^* from the deviation between the speed command value ω _r ^* and the frequency calculation value ω ₁ .

The q-axis current control calculation unit 9 outputs a second q-axis current command value Iq ^** from the deviation between the first q-axis current command value Iq ^* and the detected current value Iqc.

The d-axis current control calculation unit 10 outputs the second d-axis current command value Id ^** from the deviation between the first d-axis current command value Id ^* which is “zero” and the current detection value Idc.

The vector control calculation unit 11 determines the d-axis and q-axis voltages based on the electric constant of the permanent magnet motor 1, the second current command values Id ^** and Iq ^{**, the} frequency calculation value ω ₁ , and the inductance value L ^*. Command values Vdc ^* and Vqc ^* are output.

The coordinate conversion unit 12 outputs three-phase AC voltage command values Vu ^* , Vv ^* , Vw ^* from the voltage command values Vdc ^* , Vdc ^* and the rotation phase command value θc ^* .

The inductance search / setting unit 13 receives the q-axis current detection value Iqc, and outputs an inductance value L ^* used for calculation by the axis error estimation calculation unit 5 and the vector control calculation unit 11.

  The DC power supply 21 supplies a DC voltage to the power converter 2.

  First, the basic operation of the position sensorless control method using the present invention will be described.

In the position sensorless control, as described in Japanese Patent Application No. 2006-178895, when the resistance setting error ratio (R / R ^* ) is “1”, “the same torque can be output with a minimum motor current. However, when (R / R ^* ) deviates from “1”, there is a “problem that the current value becomes large”.

This is because if the d-axis current command value Id ^* is set to a predetermined value other than “zero”, an estimation error occurs in the calculated value Δθc of the axis error obtained by the calculation, and the “optimum current phase” cannot be maintained. Because.

Therefore, in the present invention, in order to make the resistance value R of the permanent magnet motor 1 robust,
(1) Set “d-axis current command value Id ^* ” and “axis error command value Δθc ^* ” to “zero”.
(2) The inductance value L ^* set in the control system (the axis error estimation calculation unit 5 or the vector control calculation unit 11a) is intentionally changed to generate the axis error Δθ.
(3) in the period in which by changing the L ^*, detects a current detection value of the q-axis Iqc (motor current I ₁ or equivalent), the optimum current Iqc is minimized (the axis error Δθ is, which generates the maximum torque Search for the inductance value at a point that matches the phase.
(4) The searched inductance value is set again in the control system.

  With this series of operations, high-efficiency operation can be realized.

  From here, the operation principle of the high-efficiency control according to the present invention will be described.

  The motor torque τm is shown in (Equation 1).

Where Pm: number of pole pairs of motor, Ke: power generation coefficient
Ld: d-axis inductance value, Lq: q-axis inductance value
Id: d-axis current, Iq: q-axis current In the configuration shown in FIG. 1, highly efficient control operation is performed with the d-axis current command value Id ^* and the shaft error command value Δθc ^* set to “zero”. the axis error that can be realized is defined as [Delta] [theta] _opt.

When the axis error Δθ _opt occurs, the coordinate transformation matrix from the currents Idc, Iqc on the control axis (dc-qc) axis to the currents Id, Iq on the motor axis (dq) axis is (Equation 2) Become.

Further, the current phase θi (phase angle between the q-axis current Iq and the motor current I ₁ ) at which the permanent magnet motor 1 generates the maximum torque is defined as (Equation 3).

  That is, “X” is a “ratio of the d-axis current Id to the q-axis current Iq” that achieves the maximum torque, that is, a value of “Id / Iq”.

Here, assuming that [Delta] [theta] _opt matches the current phase _{θi (Δθ opt = θi),} ( Equation 2) is substituted into the equation (3), by setting the d-axis current command value Id ^* to the "zero" From the relationship (Id ^* = Idc = 0)

  From (Equation 4), it can be seen that when an axis error occurs, a d-axis current Id flows even if Idc is “zero”.

  Substituting (Equation 4) into (Equation 1), which is the torque equation of the motor,

  Here, to obtain the current ratio “X” when the maximum torque is generated, Equation (6) may be solved.

  Solving for the current “X” yields (Equation 7).

By substituting (Equation 7) with the current phase θi of (Equation 2) as Δθ _opt , (Equation 8) can be obtained.

Here, if the shaft error Δθ _opt occurs in the relationship shown in (Equation 8), “minimization of the motor current at the same torque” can be performed, and a highly efficient control operation can be realized.

  By the way, the basic equation of the axis error calculation described in Japanese Patent Laid-Open No. 2001-251889 (Equation 9) uses the q-axis inductance value Lq for the calculation of Δθc.

The calculated value Δθc of the axis error shown in (Equation 9) generates an estimation error that depends only on the q-axis inductance Lq ^* (that is, the axis error Δθ is generated due to the error of Lq ^* ).

Therefore, an inductance value L ^* that is intentionally changed is newly introduced instead of the q-axis inductance setting value Lq ^* set in the axis error estimation calculation unit 5 and the vector control calculation unit 11.

By intentionally changing this L ^* , an axial error Δθ occurs, and when the axial error Δθ coincides with the current phase θi, the motor current I ₁ becomes the minimum value. That is, the inductance value L ^* set at that time is an inductance value that can realize highly efficient operation.

Next, the relationship between the inductance value L ^* and the axis error Δθ will be described.

In the vector control calculation unit 11 of FIG. 1, the current command values Id ^** ,
Using the qq ^** , frequency calculation value ω _1, motor constant setting value, and q-axis inductance value Lq ^* , the d-axis and q-axis voltage command values Vdc ^* and Vqc ^* shown in (Equation 10) are calculated. To do.

  Here, when the axis error Δθ exists, the applied voltages Vd and Vq of the motor calculated on the control side are (Equation 11).

  On the other hand, the d-axis and q-axis motor applied voltages Vd and Vq are expressed as (Equation 12) using the axis error Δθ, current detection values Idc and Iqc, and motor constants.

Here, from the relationship of (Equation 11) = (Equation 12), the d-axis current command value Id ^* is set to “zero” (Id ^* = Idc = 0), and the q-axis current command value Iq ^* is set to a predetermined value. Considering the value (Iq ^* = Iqc), Id ^** and Iq ^** , which are the output values of the d-axis and q-axis current control calculation units 9 and 10, are given by (Expression 13).

In addition, the axis error estimation calculation unit 5 uses the d-axis and q-axis current detection values Idc and Iqc, the frequency calculation value ω _{1, the} motor constant and the inductance value L ^* to calculate the axis error calculation value Δθc as 14).

  Here, when (Equation 10) and (Equation 13) are substituted into (Equation 14),

The frequency calculation unit 6 calculates the frequency ω ₁ so that the axis error calculation value Δθc that is the output value of the axis error estimation calculation unit 5 matches the command value Δθc ^* of the axis error that is “zero”. At a constant speed, the numerator of (Equation 15) is “zero”.

The equation (16) including the axis error Δθ does not include the term of the resistance value R of the motor, and the calculation of the frequency ω ₁ is not affected by the resistance component of the motor (is robust). .

  Further, when the axial error Δθ is arranged, (Equation 17) is obtained.

From (Equation 17), it can be seen that Δθ is “sensitive only to the inductance value L ^* ” among the set values.

That is, by changing L ^* , the axis error Δθ can be intentionally generated.

In Figure 1, the inductance searching / setting unit 13, by intentionally changing the L ^*, then select the L ^* the magnitude of the detected current value Iqc of the q-axis generated in the period is a minimum, was modified In addition, it is used for vector control calculation and axis error estimation calculation.

The configuration of the inductance searching / setting unit 13, L ^* a "search section" is provided with a "setting unit" for each predetermined time, performed the inductance L ^* a "search operation" and "setting operation".

In the “search unit”, the inductance L ^* is changed in a predetermined time with a step (step-like) or with a certain inclination, and the detected current value Iqc of the q-axis of the motor generated at this time is detected.

Next, an inductance value L ^* _opt at Iqc _min where the detection value Iqc is minimized during the period in which L ^* is changed is selected.

After the end of the search operation, the operation moves to L ^* _opt setting operation.

In the “setting unit”, the signal L ^* _opt is substituted into L ^* and is output to the axis error estimation calculation unit 5 and the vector control calculation unit 11. If control calculation is performed using this L ^* , current minimization at the same torque can be performed, and automatic high-efficiency operation can be realized.

  By repeating this “search operation” and “setting operation”, high-efficiency operation can be realized under any operating condition.

  Here, a flowchart of the inductance search / setting unit 13 which is a characteristic of the present invention will be described with reference to FIG.

1) Judgment of execution of “search mode” When there is not much change in the load torque and the magnitude is substantially constant, or when the period of change of the load torque is known in advance, using a timer inside the control calculation, for example, The “search mode” is executed every “predetermined time” of several ms to several minutes.

2) Execution of “search mode” In the “search mode”, the inductance value L ^* is changed within a predetermined time so as to have a predetermined step width or a predetermined inclination. In addition, the generated q-axis current detection value Iqc (or q-axis current command value Iq ^* ) is also stored during the period of changing L ^* (several to several tens of points are sufficient).

When the process of changing L ^* is completed, the minimum point Iqc _min of the detected current value Iqc detected in the search period is searched, and the inductance L ^* set at that time is selected as the optimum inductance L ^* _opt .

3) Execution of “setting mode” The inductance L ^* _opt selected in the “search mode” is substituted for L ^* , and is set in the vector control calculation unit 11 and the axis error estimation calculation unit 5 to continue operation.

  FIG. 3 shows an example of the effect of the “inductance search / setting unit 13”, which is a feature of the present invention.

In the control device of FIG. 1, the operation waveforms of the respective parts and the magnitude of the motor current I _{1 in} the “search mode” and “setting mode” shown in the flowchart of FIG. did.

In the operation of “search mode” in FIG. 3 (1), the search mode is executed by the timer operation “every predetermined time” at point a. In the present embodiment, as an example, for a motor having a q-axis inductance Lq greater than the d-axis inductance Ld, L ^* is changed stepwise from the q-axis inductance value Lq to the vicinity of the d-axis inductance value Ld. It can be seen that the motor current I ₁ changes as L ^* changes.

Next, when the step of changing L ^* is completed, the minimum point (here, b point) of the detected current value detected during the search mode period is searched.

Here, since the d-axis current command value Id ^* is set to “zero”, the q-axis current detection value Iqc corresponds to the motor current I ₁ (I ₁ = Iqc).

Also, L ^* at the point c set at the current minimum point b during the search mode period is selected as the optimum inductance value L ^* _opt .

In the “setting mode” in FIG. 3B, the inductance value L ^* _opt is set as a new inductance value L ^* , and the operation is continued. At this time, it can be seen that the motor current I ₁ can be operated at the current minimum point (80% current).

In this embodiment, L ^* is changed stepwise with a predetermined change width, but the same effect can be obtained even if it is changed to have a predetermined inclination.

L ^* may be changed from the d-axis inductance value Ld to the q-axis inductance value Lq.

  After this, even if the load torque changes, high-efficiency operation is automatically realized according to the load conditions by repeating a series of operations of “search mode” and “setting mode” at predetermined time intervals. be able to.

If the application does not change the load torque, the operation of the inductance search / setting unit may be activated once, and thereafter, the searched value L ^* may be used as it is.

[Second Embodiment]
FIG. 4 executes the “search mode” in the “inductance search / setting unit” of the present invention when “a change in load torque is detected”.

  This is effective for applications where the load torque changes during actual operation.

  In the figure, constituent elements 1 to 12 and 21 are the same as those in FIG.

The inductance search / setting unit 13a is executed when a change in load torque is detected. The inductance search / setting unit 13a receives the q-axis current detection value Iqc and uses the inductance value L used for the calculation of the axis error estimation calculation unit 5 and the vector control calculation unit 11. ^{* Is} output.

  Here, a flowchart of the inductance search / setting unit 13a, which is a characteristic of the present invention, will be described with reference to FIG.

1) Determination of “Search Mode” Execution “Motor torque change” is detected by detecting q-axis current detection value Iqc proportional to motor torque.
When (or current command value Iq ^* ) “changes at a predetermined rate of change”, “search mode” is executed.

  Thereafter, as in the first embodiment, 2) “search mode” and 3) “setting mode” are executed.

  FIG. 6 shows blocks related to the determination of execution of the “search mode” in 1) above.

  In the configuration, the q-axis current detection value Iqc is input to the absolute value calculation unit 13a1. The output signal 13a1 is input to the differential operation unit 13a2 and compared with the current change rate K13a3.

  When the output signal of 13a2 is larger than the current change rate K13a3, the flag “TL_detect_flg” is set to “1” in the flag setting unit 13a4, and when the output signal of 13a2 is smaller than the current change rate K13a3, the flag “ Set “TL_detect_flg” to “0”.

  Only when the “TL_detect_flg” is “1”, the process proceeds to the execution of the “search mode” in 2).

  Here, the current change rate K13a3 can be arbitrarily set, and may be set in accordance with the change rate of the load torque of the actual machine.

  FIG. 7 shows the effect of the “inductance search / setting unit 13a”, which is a feature of the present invention.

In the control device of FIG. 1, an impact-like 100% load torque is applied to the motor 1, and the operation waveform of each part and the magnitude of the motor current I ₁ are observed in the “search mode” and “setting mode”.

  In the operation of FIG. 7 (1) “search mode”, impact load torque of 100% is applied at point a ′.

Here, a change in torque is detected (flag “TL_detect_flg” is “1”), and a process of changing the inductance value L ^* is entered.

In the present embodiment, as an example, for a motor having a q-axis inductance Lq greater than the d-axis inductance Ld, L ^* is changed stepwise from the q-axis inductance value Lq to the vicinity of the d-axis inductance value Ld. It can be seen that the motor current I ₁ changes as L ^* changes.

Next, when the step of changing L ^* is completed, the minimum point (here, b ′ point) of the current detection value detected during the search mode period is searched.

Here, since the d-axis current command value Id ^* is set to “zero”, the q-axis current detection value Iqc is equivalent to the motor current I ₁ (I ₁ = Iqc).

Further, L ^* at the point c ′ set at the current minimum point b ′ during the search mode period is selected as the optimum inductance value L ^* _opt .

In the “setting mode” of FIG. 7B, the inductance value L ^* _opt is set as a new inductance value L ^* , and the operation is continued. At this time, it can be seen that the motor current I ₁ can be operated at the current minimum point (80% current).

  After this, even if the load torque changes, automatic high-efficiency operation can be realized according to the load conditions by repeating a series of operations of “identification mode” and “setting mode” as before. it can.

  In the first embodiment, the “search mode” is executed “every predetermined time”, but in that case, there is a concern about the occurrence of periodic noise.

  Therefore, if the “search mode” is executed only when a torque change occurs as in the present embodiment, there is an effect of reducing periodic noise.

[Third embodiment]
FIG. 8 shows another embodiment of the present invention.

In the first embodiment, the inductance search / setting operation is performed during actual operation. In this embodiment, every time the inductance search / setting unit executes the “setting mode”, “q-axis current detection” is performed. A table of the relationship between the minimum value point Iqc _min "and the" inductance L ^* "is created, and from the next" search mode ", an initial value of the inductance L ^* is set from the created table.

  In the figure, constituent elements 1 to 12 and 21 are the same as those in FIG.

The inductance search / setting unit 13b receives the q-axis current detection value Iqc, and outputs the inductance value L ^* , “minimum value Iqc _{min of} q-axis current detection value”, and “optimum inductance value L ^* _opt ”. .

The inductance table 14 creates a table of the relationship between “the minimum point Iqc _{min of the} q-axis current detection value” and “inductance L ^* ” each time the inductance search / setting unit 13b executes the “search mode”. It is.

  The determination of execution of “search mode” may be performed by either the method of the first embodiment (FIG. 2) or the method of the second embodiment 2 (FIGS. 5 and 6).

  FIG. 9 shows the configuration of the inductance table 14.

In the inductance table 14, the “minimum value Iqc _{min of} q-axis current detection value” and “optimum inductance L ^* _opt ” obtained when the inductance search / setting unit 13 b executes the “search mode” are input. When the q-axis current detection value Iqc is input, a table for outputting the inductance value L ₀ ^* is created and stored during actual operation.

From the next execution of the “search mode”, L ₀ ^* is read in the inductance table 14 and is input to the inductance search / setting unit 13b, and L ^* is set to an initial value when variable. According to this embodiment, the period for changing L ^* is shortened, and automatic high-efficiency operation can be realized quickly.

[Fourth embodiment]
FIG. 10 shows another embodiment of the present invention.

In the first embodiment, the inductance search / setting operation is performed during actual operation. In this embodiment, every time the inductance search / setting unit executes the “setting mode”, “q-axis current detection” is performed. A table of the relationship between the minimum value Iqc _min "and the" inductance L ^* "is created, and the inductance L ^** is referenced from the created table from the next activation.

  In the figure, constituent elements 1 to 12 and 21 are the same as those in FIG.

The inductance search / setting unit 13c receives the q-axis current detection value Iqc, and outputs the inductance value L ^* , “minimum q-axis current detection value Iqc _min ”, and “optimum inductance value L ^* _opt ”. .

  The determination of execution of “search mode” may be performed by either the method of the first embodiment (FIG. 2) or the method of the second embodiment 2 (FIGS. 5 and 6).

The inductance table 14a creates a table of the relationship between “the minimum value Iqc _{min of the} q-axis current detection value” and “inductance L ^** ” each time the inductance search / setting unit 13c executes the “setting mode”. Is.

The inductance setting switching unit 15 switches and outputs the output value L ^* of the inductance search / setting unit 13c and the output value L ^** of the inductance table 14a.

  FIG. 11 shows the configuration of the inductance table 14a.

In the inductance table 14a, the “minimum point Iqc _{min of} q-axis current detection value” and “optimum inductance L ^* _opt ” obtained when the inductance search / setting unit 13c executes the “search mode” are input. When the q-axis current detection value Iqc is input, a table for outputting the inductance value L ^** is created and stored during actual operation.

At the first start-up, SW = 0 is selected in the inductance setting switching unit 15 and the output L ^{* of} the inductance search / setting unit 13c is output. However, the determination condition for executing the “search mode” is intentionally relaxed. ("Execute every short time" or set the current change rate K to a small value and "execute even a slight torque change") to perform this operation frequently.

If the inductance table 14a can be created, SW = 1 may be selected and L ^{** of the} inductance table 14a may be output from the next activation.

  According to the present embodiment, the “search mode” can be omitted to eliminate periodic noise, and automatic high-efficiency operation can be realized quickly.

Further, when L ^* in the entire q-axis current detection value Iqc, which is the operation region, can be grasped, the switch of the inductance setting switching unit 15 is set to SW = 1, and L ^** which is the output of the inductance table 14a By using, automatic high-efficiency operation can be realized more promptly without waiting for the next start-up.

[Fifth embodiment]
An example in which the present invention is applied to a module will be described with reference to FIG.

  This example shows an embodiment of the first example.

  Here, coordinate conversion unit 4, axis error estimation calculation unit 5, frequency calculation unit 6, phase calculation unit 7, speed control calculation unit 8, q-axis current control calculation unit 9, d-axis current control calculation unit 10, vector control calculation The unit 11, the coordinate conversion unit 12, and the inductance search / setting unit 13 are configured using a one-chip microcomputer.

  Further, the one-chip microcomputer and the power converter 2 are housed in one module configured on the same substrate.

  The module here means “standardized structural unit”, and is composed of separable hardware / software components.

  In addition, although it is preferable to comprise on the same board | substrate on manufacture, it is not limited to the same board | substrate.

  From this, it may be configured on a plurality of circuit boards built in the same housing.

  In other embodiments, the same configuration can be adopted.

In the first to fifth embodiments, the second current command value (Id ^** , Iq ^** ) is obtained from the first current command value (Id ^* , Iq ^* ) and the detected current value (Idc, Iqc). Created and performed vector control calculation using this current command value,
1) A voltage correction value (ΔVd, ΔVq) is created from the current detection value (Idc, Iqc) in the first current command value (Id ^* , Iq ^* ), and the voltage correction value (ΔVd, ΔVq) Using the first current command value (Id ^* , Iq ^* ), the frequency calculation value ω ₁ , the electrical constant of the permanent magnet motor 1 and the inductance value L ^* , the voltage command values (Vdc ^* , Vqc ^* ) according to (Equation 18) ) To calculate vector control,
2) First d-axis current command value Id ^* (= 0), first-order lag signal Iqctd and speed command value ω _r ^{* of} q-axis current detection value Iqc, electrical constant and inductance value L ^{* of} permanent magnet motor 1 Can also be applied to a vector control calculation method for calculating voltage command values Vdc ^* and Vqc ^* according to (Equation 19).

また、第１から第５の実施例では、高価な電流検出器３で検出した３相の交流電流Ｉｕ〜Ｉｗを検出する方式であったが、電力変換器２の過電流検出用に取り付けているワンシャント抵抗に流れる直流電流から、３相のモータ電流Ｉｕ＾，Ｉｖ＾，Ｉｗ＾を再現し、この再現電流値を用いる「低コストなシステム」にも対応することができる。

In the first to fifth embodiments, the three-phase AC currents Iu to Iw detected by the expensive current detector 3 are detected. The three-phase motor currents Iu ^, Iv ^, Iw ^ can be reproduced from the direct current flowing through the one-shunt resistor, and the "low-cost system" using this reproduced current value can be dealt with.

As described above, according to the present invention, the inductance value corresponding to the q-axis used for the vector control calculation and the axis error estimation calculation is changed to search for and find the inductance at which the motor current becomes the minimum point at the same torque. When the obtained inductance value is newly used for vector control calculation or axis error estimation calculation, there is an error in the resistance setting error (R−R ^* ) or there is a setting error in other control constants. In this case, a “permanent magnet motor high-efficiency speed control device” capable of automatically performing high-efficiency operation can be provided.

The block diagram of the high efficiency speed control apparatus of the permanent magnet motor which shows one Example of this invention. The flowchart of the inductance search / setting unit 13. Operation waveform in search / set mode. The block diagram of the highly efficient speed control apparatus of the permanent magnet motor which shows another Example. The flowchart of the inductance search / setting part 13a. The block diagram related to determination of search mode execution. Operation waveform in search / set mode. The block diagram of the highly efficient speed control apparatus of the permanent magnet motor which shows another Example. Explanatory drawing of the inductance table 14. FIG. The block diagram of the highly efficient speed control apparatus of the permanent magnet motor which shows another Example. Explanatory drawing of the inductance table 14a. An example of the block diagram which shows embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Permanent magnet motor 2 Power converter 3 Current detectors 4 and 12 Coordinate conversion unit 5 Axis error estimation calculation unit 6 Frequency calculation unit 7 Phase calculation unit 8 Speed control calculation unit 9 q-axis current control calculation unit 10 d-axis current control calculation Unit 11 Vector control calculation units 13, 13a, 13b, 13c Inductance search / setting units 14, 14a Inductance table 15 Inductance setting switching unit 21 DC power supply L ^* , L ^** Inductance value Id ^* first d-axis current command value Id ^** second d-axis current command value Iq ^* first q-axis current command value Iq ^** second q-axis current command value Idc d-axis current detection value Iqc q-axis current detection value Δθc axis error estimated value Δθ Axis error ω ₁ Frequency calculation value

Claims (11)

A vector control operation unit that controls the output frequency and output voltage of the power converter that drives the permanent magnet motor, and an axis error that is a deviation between the rotational phase command value of the power converter and the rotational phase value of the permanent magnet motor In a control apparatus for a permanent magnet motor having an axis error estimation calculation unit and a frequency calculation unit for controlling a frequency command value so that the axis error is zero,
An inductance search unit that searches for an inductance value at which the detected value of the motor current becomes the minimum point by changing the inductance value used for vector control calculation and axis error estimation calculation,
A control apparatus for a permanent magnet motor, wherein the inductance value obtained by the search is set in a vector control calculation or an axis error estimation calculation. The control apparatus for a permanent magnet motor according to claim 1, wherein the inductance search unit changes the inductance value within a predetermined time so as to have a predetermined step width or a predetermined inclination.   2. The control apparatus for a permanent magnet motor according to claim 1, wherein the inductance value searching and setting operations are executed at predetermined time intervals.   2. The permanent magnet motor control device according to claim 1, wherein the inductance value searching and setting operations are executed when a load torque or a motor current value changes. In claim 4,
When the load torque or motor current value changes,
It is characterized by detecting a change rate of a q-axis current detection value or a q-axis current command value and comparing the change rate with a predetermined change rate value to detect a load torque change or a motor current value. To control a permanent magnet motor. In claim 1,
A control device for a permanent magnet motor, characterized in that a table of a relationship between an inductance value at which the motor current becomes a minimum point and a q-axis current detection value or command value is created. The control device for a permanent magnet motor, wherein an inductance value used for vector control calculation and axis error estimation calculation is changed along the table created in claim 6. In claim 1,
A permanent magnet motor is characterized in that a table of inductance values in the entire operation region of the q-axis current detection value or command value is created, and thereafter the inductance search is not performed, and the inductance value is set by the created table. Control device. In claim 1,
The control apparatus for a permanent magnet motor, wherein the motor current is estimated based on a direct current flowing in a one-shunt resistor attached to a direct current side of the power converter. A vector control operation that controls the output frequency and output voltage of the power converter that drives the permanent magnet motor, and an axis that estimates the axis error that is the deviation between the rotational phase command value of the power converter and the rotational phase value of the permanent magnet motor In the control method of the permanent magnet motor that performs the error estimation calculation and the frequency calculation for controlling the frequency command value so that the axis error is zero,
Searching for an inductance value at which the motor current becomes the minimum point by changing the inductance value used for vector control calculation and axis error estimation calculation;
A method for controlling a permanent magnet motor, comprising the step of using the inductance value obtained by the search for vector control calculation and axis error estimation. A vector control operation unit that controls the output frequency and output voltage of the power converter that drives the permanent magnet motor, and an axis error that is a deviation between the rotational phase command value of the power converter and the rotational phase value of the permanent magnet motor In a module including a power converter, a controller for a permanent magnet motor having an axis error estimation calculation unit, a frequency calculation unit for controlling a frequency command value so that the axis error is zero,
An inductance search unit that searches for an inductance value at which the detected value of the motor current becomes the minimum point by changing the inductance value used for vector control calculation and axis error estimation calculation,
A module, wherein the inductance value obtained by searching is set in a vector control calculation or an axis error estimation calculation.

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