JP3095566B2 - Synchronous machine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for driving a synchronous machine, for example, a synchronous motor with a variable voltage and variable frequency power supply such as a cycloconverter or an inverter.

[0002]

2. Description of the Related Art As a system for driving a synchronous motor at a variable voltage and a variable frequency, there are a non-commutator motor system using a separately excited commutation and a vector control system. Among them, the vector control method is applied to a field in which high-performance driving is possible, fast response and precise control are required. FIG. 11 is an example of the related art,
1 is a power converter, 2 is a synchronous motor, 3 is a position detector, 4
Is a field power converter, 5 is a position calculator, 6 is a coordinate converter, 7 and 8 are amplifiers, 9 is a magnetic flux calculator, 10 is a field current calculator, and 11 and 12 are current detectors.

The armature current of the synchronous motor 2 is detected by a current detector 1
1 and a coordinate converter 6 based on the rotor position of the synchronous motor 2 obtained from the position detector 3 and the position calculator 5.
In the component i _q perpendicular to the field magnetic pole direction component i _d and field poles of the armature current (1), determined by equation (2). _id = (2/3) ^1/2 _{(I a cos θ + i b} cos (θ + 2 / 3π) + i c cos (θ + 4 / 3π)) ... (1) i q = (2/3) 1/2 _{(I a sin θ + i b} sin (θ + 2 / 3π) + i c sin (θ + 4 / 3π)) ... (2) (1), (2) _{where, i a, i b, i} c is detected three-phase currents The value θ represents the rotor position.

[0004] flux calculator 9, i _d, i _q and the current detector 12 internal phase angle δ is the angle between the magnetic flux φ and field poles and the magnetic flux from the detected field current i _f by (3) ,
The calculation is performed using the equations (4), (5), and (6). _{φ d = M d · [(} 1 + L kd · S / R kd) ÷ (1 + M d · S / R kdLkd · S / R kd)] · (i d + i f) + L a i d ... (3) φ q _{= M q · [(1 +} L kq · S / R kq) ÷ (1 + M q · S / R kq + L kq · S / R kq)] · (i q) + L a i q ... (4) φ = (φ d ² + φ _q ² ) ^1/2 (5) δ = a tan (φ _q / φ _d ) (6)

In equations (3) and (4), S represents a Laplace operator, M _d and M _q represent mutual inductances in the d-axis direction and the q-axis direction, and R _kd and R _kq are respectively d-axis damper winding resistance, represents a q-axis damper winding resistance, further L _kd, L _kq represents respectively d-axis damper leakage inductance, the q-axis damper leakage inductance, L _a represents the armature leakage inductance. The field current calculator 10 determines the field current command _if ^* from equation (7) from the deviation between the magnetic flux command φ ^* and the magnetic flux φ and the internal phase difference angle δ. In ^{_{i f * = K M · (}} φ * -φ) / cos δ ... (7) the above equation, K _M is a proportionality constant.

The field current command _if ^* The difference between the detected value _if and the detected value _if is amplified by the amplifier 8 to obtain the field voltage reference, and power is supplied to the field winding 21 by the field power converter 4. Also, the armature current command value _id ^* , I _q ^* And the detection current _id ,
The i _q deviation is amplified by the amplifier 7, the armature voltage command vd
^* , Vq ^* Get this command vd ^* , Vq ^* The power converter 1 is controlled based on this.

[0007]

In the conventional example shown in FIG. 11, the magnetic flux φ and the internal phase difference angle δ are obtained based on the detected currents i _d , i _q , and _if, and based on the obtained values. Field current command _if ^* Is determined. In other words, i _d, i _q, i all field current control error of the _f command i _f ^* It has a configuration that affects

In an actual control device, there are a control delay and a detection delay, and the detected value always involves a transient control error with respect to the command value. In particular, when the current must be changed abruptly, for example, in the case of a large load change, the control error of the armature current and the field current becomes large, and the field current command _if ^* attempts to absorb the error ^. Changed excessively and, in the worst case, became out of control.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to prevent a field current command from changing excessively and to control a synchronous machine stably and accurately even under a heavy load. To provide a control device that can perform the control. A second object, in addition to the first object, is to provide a high-efficiency synchronous machine control device that controls the power factor of a synchronous machine to one.

[0010]

According to a first aspect of the present invention, there is provided a synchronous machine for driving a synchronous machine by a power converter for supplying power of a movable voltage to a variable frequency. In the control device, from the q-axis current command which is an armature current orthogonal to the field pole direction of the synchronous machine, using a synchronous machine constant, a q-axis magnetic flux command which is a component orthogonal to the field pole of the magnetic flux is used. A q-axis magnetic flux calculator for calculating, a d-axis magnetic flux calculator for vector-wise subtracting the q-axis magnetic flux command from the magnetic flux command to obtain a d-axis magnetic flux command which is a field pole direction component of the magnetic flux command; A synchronous machine control device including: a field current command calculator that calculates a field current command using a synchronous machine constant from a magnetic flux command and a d-axis current command that is an armature current in a field pole direction. .

According to a second aspect of the present invention, there is provided a synchronous machine driving apparatus for driving a synchronous machine by a power converter for supplying power of a variable voltage to a variable frequency. An armature orthogonal to the d-axis current command, which is an armature current in the direction of the field magnetic pole, from a torque command, a magnetic flux command of the synchronous machine, and a q-axis magnetic flux command that is a component orthogonal to the field pole of the magnetic flux. An armature current command calculator for calculating a q-axis current command which is a current; a q-axis magnetic flux calculator for calculating the q-axis magnetic flux command from the q-axis current command using a synchronous machine constant; And a d-axis magnetic flux calculator that obtains a d-axis magnetic flux command, which is a field pole direction component of the magnetic flux command, by subtracting the q-axis magnetic flux command in a vector manner from the d-axis magnetic flux command and the d-axis current command. Using the machine constant, the field current command A control system for a synchronous machine and a calculation for the field current command calculator.

According to a third aspect of the present invention, there is provided a synchronous machine driving apparatus for driving a synchronous machine by a power converter for supplying power of a variable voltage to a variable frequency. From the torque command, the magnetic flux command, and the q-axis magnetic flux command and the d-axis magnetic flux command, which are components orthogonal to the field pole of the magnetic flux, d is the armature current in the field pole direction.
An armature current command calculator for calculating a d-axis current command, which is an armature current orthogonal to the axis current command and the field pole direction, and the q-axis magnetic flux command from the q-axis current command using a synchronous machine constant. And a d-axis magnetic flux calculator that vectorally subtracts the q-axis magnetic flux command from the magnetic flux command to obtain a d-axis magnetic flux command that is a component of the magnetic flux command in the field pole direction, From the d-axis magnetic flux command and the d-axis current command,
A synchronous machine control device comprising: a field current command calculator for calculating a field current command using a synchronous machine constant.

[0013]

According to the invention corresponding to claim 1, when the d-axis current command, the q-axis current command and the magnetic flux command are given, the q-axis magnetic flux calculator, the d-axis magnetic flux calculator and the field current command calculator are provided. The signals are sequentially transmitted, and the field current command is determined forward.
That is, the field current command is given as a necessary value when the armature current and the field current completely match the command value,
The field current command is not affected by the armature current and the transient control error of the field current. Therefore, the field current command does not change excessively even during a high load change, and a stable control system is provided.

According to the second and third aspects of the present invention, the d-axis current command and the q-axis current command are set so that the armature current vector obtained by the d-axis current command and the q-axis current command is orthogonal to the magnetic flux.
The shaft current command is determined. Therefore, in a steady state in which the armature current and the field current follow the command value, the power factor of the synchronous machine is maintained at 1, and the control device for the synchronous machine is stable and highly efficient even under a heavy load.

[0015]

FIG. 1 is a block diagram showing a schematic configuration diagram of a first embodiment for achieving the first object of the present invention. FIG.
An amplifier 8 provided in the conventional example 1 and a magnetic flux calculator 9;
The difference is that the field current calculator 10 is not provided, and instead a q-axis magnetic flux calculator 13, a d-axis magnetic flux calculator 14, and a field current command calculator 15 are provided. Since this is the same as the conventional example, its description is omitted here.
FIG. 2 is a block diagram showing a detailed configuration of the q-axis magnetic flux calculator 13, which includes proportional units 131 and 134 and an integrator 13.
2 and a function generator 133. FIG. 3 is a block diagram showing a detailed configuration of the d-axis magnetic flux calculator 14, which includes multipliers 141 and 142 and a square root calculator 143. FIG. 4 is a block diagram showing a detailed configuration of the field current command calculator 15, which includes proportional units 151 and 15.
4, a function generator 152, and a differentiator 153.

The q-axis magnetic flux calculator 13 inputs a q- axis current command iq ^* , which is a component orthogonal to the field pole of the armature current command, as shown in FIG. A q-axis magnetic flux command φ _q ^*, which is a direction component orthogonal to the field pole of the magnetic flux command, is calculated by the voltage equation). _{^{φ q * = [(R kq}} · i q * / S) * + L kq · i q] ÷ [1 + 1 / M q (R kq / S + L kq] + L a · i q * ... (8)

In the equation (8), S represents a Laplace operator, M _q is a mutual inductance in the q-axis direction, and R _kq is a q
Axis damper winding resistance, L _kq is the q-axis damper leakage inductance, L _a is the armature leakage inductance.

Normally, due to the effect of magnetic saturation, M _{q in the} equation (8)
Changes according to the magnitude of the magnetic flux. Therefore, the q-axis magnetic flux calculator shown in FIG. 2 is a block diagram showing the calculation of equation (8) using the term relating to 1 / M _q as a function generator.

The d-axis magnetic flux calculator 14 has a q-axis magnetic flux command φ calculated by the q-axis magnetic flux calculator 13 as shown in FIG.
_q ^* Is the magnetic flux command φ ^* From the field pole component φ _d ^{* of the} magnetic flux command ^. Is calculated. This corresponds to equation (9). φ _d ^* = (Φ ^{* 2-} φ _q ^{* 2} ) ^1/2 … (9)

D calculated by the d-axis magnetic flux calculator 14
Shaft magnetic flux command φ _d ^* Field poles direction component of the armature current command i _d ^* Is input to the field current command calculator 15.
The field current command calculator 15 calculates the d-axis magnetic flux command φ _d ^* based on the voltage equation of the synchronous machine as shown in FIG. And d-axis current _id ^* To calculate a field current command. Field current command _if
^* Is expressed by equation (10) from the voltage equation of the synchronous machine.

_If ^* = 1 / M _d (φ _d ^* -L _a i _d ^* ) + [(S / R _kd ) ÷ (1 + S · L _kd / R _kd )] · (φ _d ^* -L _a i _d ^* ) -I _d ^* … (10)

[0022] In (10), S is expressed equal plus operator, M _d is d-axis mutual inductance, R _kd is d-axis damper winding resistance, L _kd leakage inductance of the d-axis damper windings, L _a Represents the leakage inductance of the armature winding.

In general, M _d in the equation (10) changes according to the magnitude of the magnetic flux under the influence of the saturation. Therefore, 1 / M
_The term corresponding to _d is obtained by the function generator 152 shown in FIG.

The field current command i _f ^* determined as described above Is compared with the actual field current i _f detected by the current detector 12, the field voltage command is calculated by the amplifier (field current controller) 8. The field current controller 8 is usually constituted by a proportional integrator, and a voltage corresponding to a field voltage command is supplied to the field winding 21 of the synchronous motor 2 through the field power converter 4.
Supplied to

The three-phase armature voltage detected by the current detector 11 is converted into a current value on the dq axes by the coordinate converter 6 based on the signal from the position calculator 5. This dq
The actual value of the armature current on the axis is compared with the d-axis current command _id ^* and the q-axis current command _iq ^* , respectively, and an armature current controller (amplifier) 7 usually configured as a proportional integrator
As a result, armature voltage commands v _a ^* and v _b ^* are output. The armature voltage commands v _a ^* and v _b ^{* correspond} to the power converter 1
And the three-phase armature winding voltage is applied to the armature winding of the synchronous motor 2 to drive the synchronous motor 2.

[0026] In the above first embodiment the description is field current command of the synchronous motor 2 i _f ^* is, the armature current command i _d ^*, i _q ^*, the magnetic flux command phi _d ^* From the armature current, and is determined irrespective of the actual value of the armature current and the actual value of the field current. Therefore, even when the armature current command changes suddenly, such as when the load changes suddenly, the armature current control The field current command does not change excessively under the influence of the control error of the system and the field current control system, and the control system becomes stable.

FIG. 5 is a block diagram showing a schematic configuration of a second embodiment for achieving the second object of the present invention. This embodiment differs from the first embodiment shown in FIG.
Is different. The armature current command calculator 16 is
As described later, the torque command T ^* And magnetic flux command φ ^* And φ _q ^* from the q-axis magnetic flux calculator 13 And input the d-axis current command _id ^* And q-axis current command _iq ^* Is calculated.

FIG. 6 is a block diagram showing a detailed configuration of the armature current command calculator 16, which is a divider 160.
1,1602 and multipliers 1610, 1611, 161
2, 1613, a square root calculator 163, an arctangent function generator 1640, a sine function generator 1641, a cosine function generator 1642, and an inverter 165. FIG. 7 is a block diagram showing another detailed configuration of the armature current command calculator 16. Reference numeral 1621 denotes a divider, and other configurations are the same as those in FIG. Torque command T ^* And magnetic flux command φ ^* Is given, the magnitude I _T of the required armature current vector is determined by the following equation. I _T = T ^* ÷ φ ^* (11) The torque command T ^* Is usually given as the output of a higher-order controller such as a speed controller, and the magnetic flux command is given as a function of the speed.

On the other hand, the angle δ between the magnetic flux command vector determined by the d-axis magnetic flux command and the q-axis magnetic flux command and the field pole is determined by the equation (12) from the magnetic flux command and the q-axis magnetic flux command. δ = tan ^-1 [φ _q ^* ÷ (φ ^{* 2} −φ _q ^{* 2} ) ^1/2 ] ... (12)

In order to keep the power factor of the synchronous motor 2 at 1,
The armature current command vector may be given so as to be orthogonal to the magnetic flux command vector. That is, the d-axis current command and q
The shaft current command may be determined by equations (13) and (14). ^{_{i d * = -I T · sin}} δ ... (13) i q * = I T · cos δ ... (14)

FIG. 6 is a block diagram showing the above operation. In the calculation of FIG. 6, the sine value and the cosine value are obtained after obtaining the angle δ between the magnetic flux command vector and the field magnetic pole from the magnetic flux command and the q-axis magnetic flux command. , Sine value sin δ, and cosine value cos δ may be obtained by equations (15) and (16). sin δ = φ _q ^* / Φ ^* ... (15) cos δ = [ (φ * 2 -φ q * 2) 1/2 ] ÷ φ ^* ... (16) Using the equations (13) to (16), the d-axis current command _id ^* ,
q-axis current command i _q ^* FIG. 7 is a block diagram showing a method of determining the above.

D-axis current command _id ^* And q-axis current command _iq ^*
Is determined, the field current command is determined without being affected by the armature current control and the field current control, and the synchronous motor is controlled in exactly the same manner as the operation of the first embodiment.

According to the second embodiment described above, the field current command of the synchronous motor is calculated forward from the armature current command and the magnetic flux command, and the actual value of the armature current and the actual value of the field current are calculated. Therefore, even when the armature current command changes suddenly, such as during a sudden load change, the field current is affected by the control error of the armature current control system and the field current control system. Since the command does not change excessively, a stable control system is provided, and the armature current command vector is orthogonal to the magnetic flux command vector, so in the steady state where the armature current and field current follow the command value, the synchronous motor Is maintained at 1, and the control device for the synchronous motor has a high power factor.

FIG. 8 is a block diagram showing a schematic configuration of a third embodiment for achieving the second object. In this embodiment, the armature current command calculator 16 of the embodiment shown in FIG. 5 is not provided. 5 in that an armature current command calculator 17 shown in FIG. 9 is provided.

FIG. 9 shows the detailed configuration of the armature current command calculator 17, which is divided into dividers 1601 and 1602.
, Multipliers 1612 and 1613, and arctangent function generator 1
640, a sine function generator 1641, a cosine function generator 1642, and an inverter 165.

FIG. 10 is a block diagram showing a detailed configuration of another example of the armature current command calculator 17 (an example different from each of the above-described examples), which includes dividers 1601, 1602, 1
603, multipliers 1612 and 1613, and an inverter 165
It consists of

The armature current command calculator 16 of the embodiment shown in FIG.
In the operations performed, but the phi _q ^* from the flux command phi ^* contains operations vectorially determining the subtracted phi _d ^*,
This is the same calculation as the d-axis magnetic flux calculator 14 of FIG.
In the embodiment of FIG. 8, this calculation is performed by the armature current command calculator 17.
Is obtained by adding φ _d ^* obtained by the magnetic flux calculator 14 to the input of the armature current command calculator 17.

On the other hand, the angle δ between the magnetic flux command vector determined by the d-axis magnetic flux command and the q-axis magnetic flux command and the field magnetic pole is determined by the following equation from the magnetic flux command and the q-axis magnetic flux command. Therefore, the calculation of δ is based on the input φ _d ^* from the d-axis magnetic flux calculator 14 ^. And is calculated by equation (17). δ = tan ^-1 (φ _q ^* ÷ φ _d ^* (17) FIG. 9 shows a detailed configuration of the armature current command calculator 17 using the above equation.

In the calculation of FIG. 9, a magnetic flux command, a d-axis magnetic flux command,
From the q-axis magnetic flux command, the angle δ between the magnetic flux command vector and the field pole is obtained, and then the sine value and cosine value are obtained. As in the embodiment of FIG. 5, the d-axis magnetic flux command and the q-axis Sine value sin δ, cosine value cos directly from magnetic flux command, magnetic flux command
δ may be calculated by the following equation. sin δ = φ _q ^* ÷ φ ^* ... (18) cos δ = φ ^{d *} ÷ φ ^* (19) FIG. 10 is a block diagram showing a method of determining the d-axis current command and the q-axis current command using the above equation.

After the d-axis current command and the q-axis current command are determined, the effects of the armature current control and the field current control are determined in exactly the same manner as in the embodiment of FIG. 1 corresponding to the first object. The field current command is determined without receiving the command, and the synchronous machine is controlled.

This embodiment is excellent in stability under a high load and has a steady state in the same manner as the embodiment of FIG. 5, except that the operation of the armature current command calculator is partially omitted. A synchronous machine control device in which the synchronous electric power factor is kept at 1 is configured.

[0042]

According to the present invention, even when the armature current changes abruptly, such as when the load fluctuates suddenly, the field current command does not become excessively large and the synchronous machine is excellent in transient stability. A control device can be realized, and the synchronous power factor is set to 1 in a steady state.
A control device for a synchronous machine with a high power factor can be configured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment for a first object of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of a q-axis magnetic flux calculator of FIG.

FIG. 3 is a block diagram showing a detailed configuration of a d-axis magnetic flux calculator of FIG. 1;

FIG. 4 is a block diagram showing a detailed configuration of a field current command calculator of FIG. 1;

FIG. 5 is a block diagram showing a schematic configuration of a second embodiment for the second object of the present invention.

FIG. 6 is a block diagram showing a first example of the armature current command calculator of FIG. 5;

FIG. 7 is a block diagram showing a second example of the armature current command calculator of FIG. 5;

FIG. 8 is a block diagram showing a schematic configuration of a third embodiment for a second object.

FIG. 9 is a block diagram showing a first example of an armature current command calculator in FIG. 8;

FIG. 10 is a block diagram showing a second example of the armature current command calculator in FIG. 8;

FIG. 11 is a block diagram showing an example of a conventional synchronous motor control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power converter, 2 ... Synchronous machine, 3 ... Position detector, 4 ... Field power converter, 5 ... Position calculator, 6 ... Coordinate converter,
7, 8 amplifier, 11, 12 current detector, 13 q-axis magnetic flux calculator, 14 d-axis magnetic flux calculator, 15 field current command calculator, 16, 17 armature current command calculator.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 21/00 H02P 5/408-5/412 H02P 7/628-7/632

Claims (3)

(57) [Claims] 1. A synchronous machine control device for driving a synchronous machine with a power converter that supplies power of a movable voltage-variable frequency, wherein a q-axis current that is an armature current orthogonal to a field pole direction of the synchronous machine. A q-axis magnetic flux calculator that calculates a q-axis magnetic flux command that is a component orthogonal to the field pole of the magnetic flux using a synchronous machine constant from the command, and a vector subtraction of the q-axis magnetic flux command from the magnetic flux command,
A d-axis magnetic flux calculator for obtaining a d-axis magnetic flux command which is a component of the magnetic flux command in the direction of the magnetic field pole;
A synchronous machine control device, comprising: a field current command calculator that calculates a field current command from a shaft current command using a synchronous machine constant. 2. A synchronous machine driving apparatus for driving a synchronous machine by a power converter that supplies power of a variable voltage-variable frequency, comprising: a torque command, a magnetic flux command, and a component of a magnetic flux orthogonal to a field pole of the synchronous machine. From an q-axis magnetic flux command, an armature current command calculator that calculates a d-axis current command that is an armature current in the field pole direction and a q-axis current command that is an armature current orthogonal to the field pole direction, A q-axis magnetic flux calculator that calculates the q-axis magnetic flux command using the synchronous machine constant from the q-axis current command; and a vector-based subtraction of the q-axis magnetic flux command from the magnetic flux command, A d-axis magnetic flux calculator for obtaining a d-axis magnetic flux command that is a magnetic pole direction component; and a field current command calculation for calculating a field current command from the d-axis magnetic flux command and the d-axis current command using a synchronous machine constant. And a container The control device of the period machine. 3. A synchronous machine driving apparatus for driving a synchronous machine by a power converter that supplies power of a variable voltage-variable frequency, comprising: a torque command, a magnetic flux command, and a component of a magnetic flux orthogonal to a field pole of the synchronous machine. Armature current for calculating a d-axis current command which is an armature current in the field pole direction and a d-axis current command which is an armature current orthogonal to the field pole direction from the q-axis flux command and the d-axis flux command A command calculator, a q-axis magnetic flux calculator that calculates the q-axis magnetic flux command from the q-axis current command using a synchronous machine constant, and a vector subtraction of the q-axis magnetic flux command from the magnetic flux command, A d-axis magnetic flux calculator for obtaining a d-axis magnetic flux command, which is a component of the magnetic flux command in the direction of the magnetic field pole; and a field machine command is calculated from the d-axis magnetic flux command and the d-axis current command using a synchronous machine constant. And a field current command calculator that performs Control system for a synchronous machine, characterized in that.