SU1515322A1 - A.c. electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used to adjust the torque, speed and position of the working bodies of production mechanisms, to drive robots, in machine tools with numerical program control. The aim of the invention is to increase the energy and dynamic performance. This goal is achieved by introducing an adaptive torque regulator (AP) 7 with two inputs and three outputs into the AC drive. The AP 7 is equipped with a controlled limit unit 8, two division blocks 9, 10, four non-linearity blocks 11,12,13,14, two modulus extraction blocks 15,16, aperiodic link 17 and two adders 18,19. The first input of the AP 7 is connected to the output of the proportional-integral speed controller 6. The second input AP 7 is connected to the output of the rotational speed sensor 3. The first output of the AP 7 is connected to the control input of a pulse converter (PI) 2 current. In the electric drive, an invariant and optimal torque control is provided over the entire required range of variation of the torque and rotation frequency. This is achieved by adaptive control in dynamics and statics of the degree of use of the magnetic circuit by means of the associated variation of the rotor torque and amplitude of the rotor flux linkage, interrelated actions on the phase, frequency and amplitude of the stator current using AP 7. 6 Il.

Description

31515322

The invention relates to electrical engineering, in particular to an adjustable asynchronous electric drive, and can be used to control

torque, speed and position of the working bodies of production mechanisms equipped with asynchronous electric drives, which include a pulse inverter, a short-circuited rotor asynchronous motor, and a speed sensor, for example, electric drives of robots, electric drives of feed and main motion of machine tools with numerical program control.

The aim of the invention is to increase the energy and dynamic performance by increasing the developed acceleration, reducing losses and heating the engine, increasing the use of the engine in terms of torque and power, and expanding the range of speed control.

FIG. 1 shows a functional diagram of the AC drive; in fig. 2-5 - characteristics of nonlinearity blocks in the adaptive torque controller; in fig. 6 shows diagrams explaining the three-zone variation of the phase of the stator current and the amplitude of the rotor flux linkage depending on the required torque and measured speed. I.

The input of the controlled limiting unit 8, which forms the first input of the adaptive torque controller 7, is connected to the output of the proportional-integral speed controller 6.

The output of the controlled limit unit 8 is connected to the input of the dividend first dividing unit 9, and its control input to the output of the first nonlinearity unit 11. The output of the first dividing unit 9 is connected to the input of the divisible second dividing unit 10 connected by an output to the first input of the first adder 18.

The inputs of the dividers of blocks 9 and 10 division combined with each other and connected to the output of the second block 12 of the nonlinearity connected by the input with the output of the aperiodic link 17.

The output of the first dividing unit 9 is connected to the input of the third nonlinearity unit 13 connected by an output to the input of the first block of the module, the inputs of the first and fourth blocks of nonlinearity 11 and 14 are interconnected and connected to the output of the second block of the 16 block module, the input of which is combined with the second input the first adder 18 and forms the second input of the adaptive torque regulator 7, connected to the output of the rotational speed sensor 3.

The output of the fourth block 14 nonline

The AC motor drive and carry the output of the first unit 15 hold the asynchronous motor 1 (FU1G.1) connected by stator windings to the outputs of the pulse converter

2 currents, made with control inputs for frequency and for orthogonal 40 stator current components, sensor

3 rotational frequencies mounted on the shaft of the induction motor 1, serially connected speed setting unit 4, comparison element 5 and proportional-integral proportional controller 45

6 speed, while another input of the comparison element 5 is connected to the output of the rotational speed sensor 3.

An adaptive torque regulator 7, made with two inputs and three outputs and equipped with a controllable limit unit 8, two division blocks 9 and 10, four nonlinearity blocks 55 11-14, two modulus 15 and 16 modules, aperiodic link 17 and two adders 18 and 19.

The module module is connected to the corresponding inputs of the second adder 19 connected by an output to the input of the aperiodic link 17.

The outputs of the first 18 and second 19 summers and the output of the first dividing unit 9, respectively, forming the first second and third outputs of the adaptive torque controller 7, are connected respectively to the control inputs for the frequency and for the orthogonal stator component currents of the pulse current converter 2.

Pulse converter 2 current contains converter 20 analog-code, the output of which is connected to the inputs of two permanent programming memories 21 and 22. The outputs of the first permanent programming memory 21 are connected to digital inputs of the first and second digital-analog converters 23 and 24. The outputs of the second constant n leg programming memory

Le w module connected to the corresponding inputs of the second adder 19, the output connected to the input of the aperiodic link 17.

The outputs of the first 18 and second 19 adders and the output of the first dividing unit 9, forming the first, second and third outputs of the adaptive torque controller 7, respectively, are connected respectively to the control inputs for the frequency and for the orthogonal stator current components of the pulse current converter 2.

Pulse converter 2 current contains converter 20 analog-code, the output of which is connected to the inputs of two permanent programming memories 21 and 22. The outputs of the first permanent programming memory 21 are connected to digital inputs of the first and second digital-analog converters 23 and 24. The outputs of the second constant n leg of programming memory

devices 22 are connected to digital inputs of third and fourth digital-to-analog converters 25 and 26. The outputs of four digital-to-analog converters 23-26 are connected to the inputs of the block 27 of adders, three outputs of which are connected to the inputs of current regulators 31 via the corresponding comparison nodes 28, 29 and 30 , 32 and 33, the outputs of the latter are connected to the inputs of a pulse inverter 34, three outputs of which are connected to asyn20 via sensors 35, 36 and 37

25

thirty

35

40

the current amplitude of the rotor flux linkage depending on the current-forming component of the current and on the motor magnetization characteristic (Fig. 3) and by calculating the controlled component of the synchronous frequency and the torque-generating component of the current in inverse relation to the calculated amplitude of the rotor flux coupling, the current-forming component of the current is changed depending on the calculated moment-forming component of the current by switching their connection depending on the boundary values and the frequency of rotation (Fig. 4 and 5), And the stator current vector is given by. adaptive time regulator 2 with three parameters (FIG. 6), the required synchronous frequency tj, the required moment-forming component of the stator current i

sx

motor 1, the converter input-t5 component of the current by calculator 20 analog-code and interconnected in pairs analog inputs of digital-to-analog converters 23, 25 and 24, 26 form, respectively, control inputs for frequency and for orthogonal current components stator pulse converter 2 current.

The essence of the operation of the AC drive is that the speed of the induction motor 1 is controlled by adaptive coupled torque control and rotor flux coupling and variable magnet saturation by adjusting the three-zone stator current phase control. In this case, the phase of the current is changed using a set of nonlinearity blocks 11-14, the characteristics of which are shown respectively in FIG. 2-5, as the sum of two interrelated phase components, one of which is formed by a sweep of a synchronous frequency corresponding to the desired frequency of the rotor flux linkage and equal to the sum of the measured rotational frequency and the controlled component of the synchronous frequency, and the second is formed by a three-zone displacement of the connection between the moment-forming and current-forming current components, depending on the required torque, the measured rotational frequency and the boundary levels of the required torque 50 and the measured rotational frequency (Fig. 6); the second component of the phase, equal to the phase of the stator current relative to the rotor flux linkage, is set to be constant and equal to 145 when the boundary moment is exceeded until the boundary rotation frequency is reached (Fig.6, c, d), and in the zones below the limit moment the rotation frequency retracted relative to the flux linkage of the rotor ff.

at 190, and the required flow i +

common current stator component i

S :;

in-phase with respect to the rotor flux coupling (the digital-analog method converts the indicated stator current parameters into the required magnitudes of the instantaneous phase currents i, i, which adjust the pulse-width modulation method of the mismatch of the specified i, ii and real instantaneous phase current isa sb sc using an internal loop regulating the vector a of the stator current and a pulsed inverter.

In this case, the adaptive phase phase current regulation of the stator is produced according to two criteria simultaneously (which determines the characteristics of the nonlinearity blocks and the switch-wiring of parameters in the drive structure): according to the dynamic criterion of the motor torque invariant control (equal to ,; depending on the required torque (Fig. 6 a, b) and the measured rotational frequency (Fig. b, d, e), respectively.

At the same time, the controlled component of the synchronous frequency, the asynchronous frequency equal to the rate of change of the second component of the phase, the amplitude of the stator current and the current-forming component of the current are formed by the process of performing interrelated actions on the required torque of the electric drive, the measured rotation frequency and the flow forming

0

five

0

five

0

the current amplitude of the rotor flux linkage depending on the current-forming component of the current and the motor magnetization characteristic (Fig. 3) and by calculating the controlled component of the synchronous frequency and the torque-generating component of the current inversely related to the calculated amplitude of the rotor flux, and the current-forming component of the current is changed depending on the calculated moment-forming component of the current by switching their connection depending on the boundary values and the rotation frequency (Fig. 4 and 5), p When in use, is stator current vector is given by. adaptive time regulator 2 with three parameters (FIG. 6), the required synchronous frequency tj, the required moment-forming component of the stator current i

sx

5 times the current component by calculating

j 0

out of phase with respect to the flux linkage of the rotor ff.

at 190, and the required flow i +

common current stator component i

S :;

in-phase with respect to the rotor flux coupling (the digital-analog method converts the indicated stator current parameters into the required magnitudes of the instantaneous phase currents i, i, which adjust the pulse-width modulation method of the mismatch of the specified i, ii and real instantaneous phase current isa sb sc using an internal loop regulating the vector a of the stator current and a pulsed inverter.

At the same time, the adaptive phase current regulation of the stator is carried out according to two criteria simultaneously (which determines the characteristics of the nonlinearity blocks and the switching parameters of the parameters in the drive structure): by the dynamic criterion of invariant control of the motor torque (equality of the required torque M and actual torque M all modes)

M - M

(one)

 and according to the energy criterion of the optimal maximum torque of the motor by controlling the magnetic field (rotor current coupling V) at stator current limits ig and stator voltage U

M M,

(2)

at

S con

.t.-s i

5 I

 and

S max

(3) (4)

where Lg tons is the specified maximum or current value of the instantaneous amplitude of the stator current;

Us wvoiKc is the maximum instantaneous amplitude of the stator voltage.

The indicated process of interconnected actions on the electric drive achieves simultaneous fulfillment of the VIY (1) - (4) condition in the whole range of variation of the torque and rotation frequency to values several times higher than the nominal torque and rotation frequency values, taking into account the power capabilities of the current converter.

The AC drive works as follows.

In the initial state of the electric drive, there are no voltages at the inputs of the element 5 of the comparison U O, Ujj O and the output of the proportional-integral speed controller 6 is received and | and O. At the inputs of the adaptive controller 7, the voltage moment is zero (0, 0 c) 0), in connection with which the voltage at the outputs of block 8 of the controlled limitation, the first 9 and second 10 blocks of division are also

are zero (Uj5, O, 0). As follows from the input-output characteristic of the first non-linear unit 11 (Fig. 2), its output voltage U at Ui 0 is also zero. The voltage at the output of the second nonlinearity unit 12 is determined by the input-output characteristic shown in FIG. 3, in the flow-forming function

the stator current component igy which in the initial state of the electric drive is determined by the initial portion

(about the third block 13 nonline1

 sy

nosti. The initial output voltage of the block 13 nonlinearity

Ui

SV,

ISSj K:

proportional to the initial current-forming component of the stator current ijy, depending on the current transfer ratio K., is set, as shown in the characteristic of FIG. 4, several times less than the maximum voltage of setting the current-forming component of the stator current i i, depending on the max.

BRIDGES FROM the Required Forcing of the Current-Flow Component of the Stator Current

17 yil -aSJSP

(five)

where is the force ratio of the current-forming component of the stator current, determined by the required range of amplitude variation of the flux linkage of the rotor v depending on the range of variation of the required moment M.

The voltage at the input of the second nonlinearity unit 12, equal to the output voltage of the aperiodic link 17, depends on time, the time constant of the aperiodic link, and the output voltage of the third nonlinearity block 13 as follows.

At the output of the first module 15 allocation module, a positive polarity voltage is formed, equal in magnitude to the initial voltage setting of the current-forming component of the stator current

and

 SV.

I

1U

howled 5 I

(6)

In the absence of a measured rotational frequency, the voltage at the output of the fourth nonlinearity unit 14 is zero, which follows from the characteristic shown in FIG. five.

The voltage from the output of the first block 15 in the module is fed through the adder 19 to the aperiodic input 91515322

link 17, having a transmission function

:

W ,, (P)

Where

T -LL Rr

electromagnetic rotor time constant, rotor inductance, rotor resistance.

The established value of the output voltage of the aperiodic link 17

Lp rr

ten

The constant phase current is generated due to the fact that the analog-code converter 20 and the permanent programmable memories 21 and 22 do not switch discrete samples of the sine and cosine functions, due to the absence of voltage

the entrance. The voltages at the outputs of digital-to-analog converters 23-26 are not big, the magnitude of the initial voltage - | 5 changes, is equal to zero at the digital outputs of the current-forming component of the transducer 23 and

current and vih, I Uijvf I, and the output of block 12 is set to the initial voltage setting the amplitude of the flux linkage of the rotor U (several times lower

25 and equal: voltage iU; 5 -, „1 at the output5 0

maximum voltage Ui,

corresponding to the required maximum flux linkage of the rotor iv when the magnetic core is saturated

dah digital-to-analog converters 24 and 26. As a result, at the output of the block 27 adders are formed

three voltages set by the constant phase currents U, -sa

and, -l. and isc which

Mr. MClUt

arrive through nodes 28, 29 and 30 of comparison to the inputs of the regulators 31, 32

„At LMOIS

CFPC (

(eight)

TO

 flii5

KflKz;

amplitude forcing the amplitude of the rotor coupling flowJ transmission coefficient For the flux coupling of the rotor phase current, the output voltages of which are fed to the inputs of the elements 28, 29 and 30 of the comparison.

In the phase windings of the stator of the asynchronous motor 1, a postor is installed.

In the absence of a measured frequency

rotation (U 0), the voltage to the output current corresponding to the stationary second block 16 modulus of the modulus of the initial state of the vector is equal to zero. stator i, in this case the module is vectoSic, in the initial state, p, of the stator is equal to the initial flow of the electric drive at the output of the adaptive component of the current component of the static regulator nominal output of the adder 18, voltage

and is absent, at the second output, formed by the output of the first dividing unit 9, the voltage V is also absent, and at the third output, formed by the output of the adder 19, a constant positive

45

Asynchronous motor 1 forms a constant initial rotor flux linkage, the amplitude of which is several times smaller than the maximum amplitude H.

p max

(eleven)

voltage, I, several times lower than the maximum possible voltage at the third output. As a result, the pulse current converter 2 forms a constant output

current 1

s

several times smaller than the rated magnetizing current i

generating a nominal magnetic flux in the air gap V, "L p, -1 (and the value of isso is small from the stator current current (about 5-20%)

10 0,051, „

 0 ...

(9i

(ten)

ten

The constant phase current is generated due to the fact that the analog-code converter 20 and the permanent programmable memories 21 and 22 do not switch discrete samples of the sine and cosine functions, due to the absence of voltage

25 and equal: voltage iU; 5 -, „1 at the output5 0

dah digital-to-analog converters 24 and 26. As a result, at the output of the block 27 adders are formed

three voltages set by the constant phase currents U, -sa

and, -l. and isc which

arrive through nodes 28, 29 and 30 of comparison to the inputs of the regulators 31, 32

 and 33 currents and are developed by a pulsed inverter 34 due to a phase negative feedback on the instantaneous phase current realized by sensors 35, 36 and 37 of the instantaneous phase current, the output voltages of which are fed to the inputs of the elements 28, 29 and 30 of the comparison.

In the phase windings of the stator of the induction motor 1 is set to

 This current corresponding to the stationary initial state of the vector r, of the stator is equal to the initial flow-forming component of the stator current i 5 i s, as a result of which

45

Asynchronous motor 1 forms a constant initial rotor flux linkage, the amplitude of which is several times smaller than the maximum amplitude H.

p max

to."

(eleven)

50

55

Since the stator current vectors are i j. and the rotor flux linkages v are stationary and coincide in direction, the phase angle between them is zero, the initial moment is zero (), the rotation frequency is zero, the output voltage of the rotation frequency sensor 3 is not present (Uj 0).

When connecting to the input of the element 5, the comparison of the voltage of the task clock 11151

U of rotation U at the output of the proportional-integral speed controller 6, a voltage jump proportional to the required torque

M

KM-UM.

where K is the transmission coefficient of the drive moment. The magnitude of the step-wise voltage increment and the required torque M depend on the gain factor of the proportional part of the controller and the magnitude of the reference. With small signals of the V / K setting, the jump-like increment of the required moment at the first moment of time does not exceed the boundary level of the required moment M, which is a value several times smaller than the nominal moment M.

M 1,. M o GGR m

(12)

where rgr is the relative moment of the boundary level.

Mgr 0.05-0.5.

(13)

The zone of change of the required moment from M 0 to ± M defines the first zone of regulation of the stator current phase using the adaptive moment regulator 7 as follows.

The jump of the required torque M Mj does not exceed the minimum limit of the required torque specified by the controlled limit unit 8, which causes the output of the proportional-integral speed controller 6 to the input of the first 40 dividing unit 9

35

and,

 and,

Since the initial voltage U i is small at the second input of dividing unit 9, at its output the voltage setting the torque component of the stator current isx / K; the jump increases, and the voltage jump of Uisx is the greater, the higher UM and UM and the lower U. . The magnitude of the jump does not exceed the magnitude limited by the adaptive moment regulator 7 to the specified initial flux ratio of the rotor according to condition (11) and expressions (5) - (10):

5322

12

Ki-U, s.

VU

-l 2

S (o

.(14)

The spasmodic increase in the output voltage of the division unit 9 leads to a voltage jump at the output of the second division unit 10.

The voltage at the outputs of the first 11 and second 12 blocks of nonlinearity is missing.

In the first control zone at small values of the torque moment M MO, the forcing of the output voltage of the first division block 9 U isx is less than the boundary level U

1SX,

 K.

which is defined by the characteristic of the third nonlinearity block 13 (Fig. 14), since the nonlinearity kink boundary ij ,, () is determined at the points + is, -i using the block setting, based on the following connection of the electrical parameters

drive igXo, 0,

2 L,

Mo

3Zp-L

V

(15)

40

where ii p is the number of pole pairs 30I- m mutual inductance.

As follows from the diagram in FIG. 1 and the characteristics in FIG. 4, the output voltage of the first dividing unit 9 is fed to the input of the third unit 13 of non-35 LINEARITY, but when lijx isKolfie changes the output voltage of setting the current-forming component of the current

5W

. Output voltages of blocks 14

17 and 19 are also maintained at the above initial levels. At the output of the adder 18, a voltage jump is generated to set the controlled component of the synchronous frequency UH, which is given by the second dividing unit 10 to the ratio of the torque-forming current component to the amplitude of the rotor flow coupling:

Uw

 I, T. . L, l

(sixteen)

where the index indicates the required (specified by the control system) parameters of the asynchronous motor.

In the absence of the measured rotational clock (U i 0), the voltage at the output of the adder 18 and at the first input of the pulse current converter 2 is equal to the voltage reference of the controlled

J315

the component of the synchronous frequency aws Utos, but at the first moment of time the converter 20 analog-code and permanent programmable memories 21 and 22 determine the initial phase of the sine and cosine functions C), since this phase is discretely changed by one discrete only after the arrival of the voltage sweep pulse and (e) S after the time interval ut, equal to:

21T

  To s

 tosi

(17)

where K is the transfer coefficient for the frequency converter analog-code

.- The input voltage of the converter 20 analog-code on the i-M time interval. Using digital-to-analog converters 23-26, four voltages are generated, the magnitude of which is determined by multiplying the second and third analog input voltages of the pulse converter 2 of the current Ufs, U isy by the initial samples of the sinus and. cosine functions sinifj and sots), defined respectively by the first and second permanent programmable memories 21 and 22, which are preprogrammed according to the sine and cosine law, respectively.

Using these digital-to-analog converters and adder block 27, pairwise summing the output voltages of the digital-to-analog converters transforms the four voltages into a two-phase voltage U, s ,, C. According to the known transformation of Cartesian coordinates from the rotating coordinate system X, Y (with synchronous speed W ) to the fixed coordinate system S, B (oriented relative to the stationary axis of the stator phase a);

and, -5s (U. isxSinc /,) (18)

U; 5 Ujs ,, sinews + U; s; Cos ifj. (nineteen)

With the help of block 27 adders, the two-phase voltage Uj,;, Uj is converted into a three-phase voltage to set the instantaneous phase currents of the stator:

5322

14

and

 g

(2CQ

isb- - (4-U 5c Ufsp); (21)

 - (4-. - | - Uisp). (22)

The three-phase control voltage setting the instantaneous phase currents V., Ujb sc from the outputs of the block 27 of the accumulators, goes to the master inputs of the nodes 28, 29 and 30 of the comparison, is converted into control pulses by means of the regulators 31, 32 and 33, power keys

the pulse inverter 34 switches and using the internal control circuit of the instantaneous phase current according to the transformations (18) - (22) the phase jump of the stator current Lg of the induction motor is removed

4s + arctg -

(23)

25

s

As a result of the phase jump of the stator current 5 4 so tf I, the second component of the phase current of the stator in the first zone is regulated1)

thirty

arccg -N "23„

(24)

the momentum M, M of the asynchronous motor 1 is generated. The maintenance of the moment M M at the level of the initial impulse M i p is ensured by the fact that after a short period of time, determined according to (17) by the code width, the discrete samples are switched by sine and cosine functions using persistent programmable memories 21 and 22, the initial phase tfy

It increments in the positive or negative direction, as determined by the positive or negative polarity of the voltage.

and

Ujs

50

So-K; -leep 5-1LCh5

(25)

55

where K is the number of discretes of the positive direction} 1 is the number of discretes of the negative direction. As a result of this change in the synchronous phase c, the frequency of the rotor flux linkage is formed.

15151532216

t i a, i according to the expression (24) from 0 °

 dt at; M M about to .1 ± 45 ° at M

1 M jfMp. This follows from (24) and the conditioner arises in connection with the change of vi ii in the first zone by controlling the instantaneous phase currents with the vanity frequency according to the characteristic of the Wg block, synchronous with the frequency of the flow-nonlinear 13 (Fig. 4) and vectorial The laziness of the rotor. The diagram in FIG. 6

The synchronous rotation of the current vectors. In FIG. 6a shows the variation of the striker and the rotor flux linkage from the 10th position of the current vectors by the static frequency aJs do05 after the jump of the phaser i and the flux linkage of the rotor v in

current at angle i, determined by the condition of the first control zone at a constant (24), ensures the maintenance of the angle of magnitude (amplitude) of the flux linkage between the stator current vector igles of the rotor 1+ Ugo (Fig. 66)

the rotor flux linking at a level of 15 different moments less than M. not cent | (M), determined by the required action of the integral part with the M% proporomement, as a result of which you select the integral and integral regulator 6; the required torque of the motor M, the instant of the moment in the positive direction of the required moment of M, the occurrence (M), or in the negative rotor acceleration, the speed of the asynchronous direction (M, M, which rises to the corresponding engine increases, therefore - related change of the phase of the current according to the output of the sensor 3 of the rotation frequency (23) and the phase angle between the current does not enter the input of the comparator element 5 and the flow coupling of the rotor 4 and the input of the adaptive regulator 3 according to (24) and provides an invari - 7 moments, rectified with the help of the second control of the moment in the corresponding modup extraction unit 16 and in accordance with equation (1) in the first zone. It is fed to the inputs of the first 11 and fourth-control 14 nonlinearity blocks In the second control zone, coP at a frequency of rotation below the limit of the torus prevppenii forms at the required level detection rotational speed Np, Kakmo moment M and the boundary layer

follows from the characteristics of the block defined by condition (12),

nonlinearity (Fig. 2) and block 14; the non-structure of the electric drive switches the linearity (Fig. 5); changing the frequency due to switching the coupling of the rotation input w does not cause a 35 start of the nonlinearity block 13, the voltage on the outputs of the first -11 and determined by the characteristic of the fourth 14 blocks of nonlinearity, FIG. four.

Simultaneously, the voltage from the output of this switch

Sensor 3 rotational speed enters the structure of the drive phase current

to the second input of the adder 18, as a result of the stator, Eg varies in the second zone of the tag, of which in the adaptive controller 7 is regulated as the sum of the synchronous

moment is formed positive about-Ф зы and constant phase shift

 Speed communication for i 45. The synchronous phase C of forming the synchronous frequency Ws is a sweep of the synchronous frequency

  u) + LYDA ensure synchronous. 45 s which varies as the sum of i-, the rotation vector of the stator current and the measured rotation frequency of the rotor with

 rotor current coupling and controlled synchronous component

frequency utJ, i.e. ) +.

500) 5 U) + li), (27) In the first control zone, the electric drive operates with a small constant controllable synchro-coupling component of the rotor at a chronical frequency corresponding to the initial part of the characteristic for magnetization rotor magnetic coupling (Fig. 3) when phase rotates phasewise, varies with the grind between the stator current and the flux linkage of the dividing unit 10 by the rotor law Etz, determined by the required torque M and the moment component of the current component L f

The phase shift of the stator current relative to the rotor flux linkage in the second control zone is set by setting another connection to the stator current flow component ijy sv of the stator and the torque forming stator current component i g i determined by the characteristic of the third

block 13 nonlinearity provided

 SX

isxo

At high values of the moment M, the magnitude of the amplitude of flux linking is

With the help of the third non-linearity unit 13 connected in series and the torus 15, it varies nonlinearly depending on the first modulus separation unit 15 and the flow-forming characteristic according to FIG. 4, under condition (29), the third flow-forming input of the pulse current converter 2 in the second control zone receives a time varying voltage setting of the flow-forming component of the stator 1 current, resulting in a condition (28) using the unit 10 for dividing the flow-forming current the stator current component ig is equal in magnitude to the moment-forming stator current component

SX

 s

 eleven.

5K

(thirty)

therefore, a constant phase shift between the stator current and the flow coupled rotor is maintained in the second control zone, determined by the law of regulation

thirty

arctg - t-rsv

In this case, the absolute phase of the stator current ES, which continuously changes from the initial phase using the adaptive torque controller 7 and the pulse current converter 2, is set according to the law:

1G

S So + К г Л 5-l-l / st-Агде Ц., К; -аЧ, - is synchronous

B s o

phase.

In the second control zone, the torque of the asynchronous motor 1 and the rotor coupling are variably varied, as shown in FIG. 6, due to the change in the flow-forming component of the stator current i, which is connected

, ten

with a change in the required torque M s. help change the output voltages of two division blocks 9 and 10 due to the change in voltage at both their inputs.

When the motor torque changes, the phase shift b i does not change in magnitude, and the torque value is determined by the variable values of the stator current amplitude i5c isio of the rotor flux linkage amplitude ("(Fig. 6c).

At high values of the moment M, the magnitude of the flux linkage of the rotor changes nonlinearly depending on the flow-forming component

20

40

stator current i due to sat

The magnetic circuit, which decreases the degree of increase in the amplitude of the rotor flux linkage, v g P increases the motor torque (Fig. 6, g).

The condition of invariant torque control (1) in the second control zone is ensured by the fact that the time voltage Uj v assignment of the current-forming component of the stator current i varies through time through the adder 19 to the input of the series-connected aperiodic link 17 and the characteristic 12 ka which corresponds to the actual characteristic of magnetization of the asynchronous motor Vr (is3) (Fig. 3).

In accordance with equation (7), the output voltage of the aperiodic link 17 varies in time inertia with respect to a change in the input voltage U, s: y with a time constant Tp equal to the time constant characterizing the time variation of the amplitude of the poTopaiy flow coupling (t ):

45

T.T. L..i

SV I

(33)

where is l,

JA- 1

(34)

s-j

SO

The reduction in the mutual inductance L with an increase in the rotor flux linkage amplitude according to the magnetization characteristic Vpd) and equation (34) is taken into account by reducing the transmission coefficient of the second nonlinearity unit 12 (Fig. 3), resulting in a pronounced C1 rotor flux amplitude

proportional to the output

the voltage of the second nonlinearity unit 12 U | , corresponds to the actual amplitude of the flux linkage of the rotor U in an asynchronous motor 1.

With saturation of the magnetic circuit and increasing the amplitude of the rotor's linkage above the nominal value with increasing moment above the nominal moment in the second control zone, the established values of the current-forming and moment-forming (its components of the stator current (i, -is) increase to a lesser extent than in the unsaturated state of the magnetic circuit increasing the voltage t of setting the amplitude of the rotor 5, defined by the link), the flow coupling of the rotor v supplied from the output of the second block 12 of the non-linear. to the second inputs of blocks 9 and 10 dividing, with eTom, the amplitude of the rotor flux linking may increase briefly by 30–40% relative to

see FIG. 6,

In the third zone of regulation with increasing frequency of rotation Bbmie of the boundary level determined by the condition

w, and) „

(36)

where Ci 0.5-1 is relative boundarygr

current

nominal rotor flux linkage. Because of this, for a given

in the second zone of the required moment

М Мр the condition of minimum 25 per rotation frequency is fulfilled, the stator voltage reaches its maximum value, in connection with which the invariant control by condition (1) is carried out with the help of an adaptive moment regulator 7 30 under the action of limit (4) by decreasing 1 and the required torque M, reducing the flow-forming component of the stator current

s

 / 2 -I is J Y2 -i

sy

(35)

In dynamics, with a limited stator current (condition (3), the maximum torque condition (2) is satisfied.

In the second zone, an adaptive adjustment of the phase, frequency and amplitude of the stator current and rotor flux linkage occurs, the values of which vary in dynamics and statics in different ways.

With large disturbances on the control side U, or on the load side 35

. g.j

  i

SX

(37)

and reducing the amplitude of rotor engagement If D uj).

Increased rotational speed

The electric drive from the described beginning of the boundary level (36) leads to a different state of abrupt switching to the second control zone, since the required torque is maximum M, and the initial flow coupling is minimal and close to zero. At the outputs of dividing blocks 9 and 10, the voltage increases abruptly to maximum values, which creates a jump in the torque generation at the outputs of the first 11 and fourth 14 blocks of voltage nonlinearity, which increases with the frequency measured by the sensor 3 and the rotational voltage to the input of the second module 16 allocation module, is rectified, and after conversion in the first block 11 nonlinearity, the characteristic of which is given in

The static and current-forming components of the stator current and the synchronous frequency 50 Ф 2 are fed to the second input of the block up to their maximum values, the calculated control limit. rotor flux link amplitude

At the output of block 8 of the controlled limitation, the voltage U sets the required torque M decreases, resulting in a sharp increase due to a jump in the aperiodic input voltage

link 17 to its maximum values its tate which is the task of the required moment

 5 "AX S Maize

A sharp forced increase in the flux linkage of the rotor V causes a forced increase in NM, the smaller the higher the rotation frequency and the higher the LM at the output of the first nonlinearity unit 11. The voltage at the output of dividing unit 9 decreases, in

The second inputs of blocks 9 and 10 dividing and forced reduction of the moment-forming and flow-forming components of the stator current and the controlled component of the synchronous frequency, this leads to an abrupt phase shift of the stator current relative to the rotor flux linkage by an angle of 45 and adapting the electric drive to the disturbing effect at the fulfillment of conditions (1) - (3) due to the establishment after the completion of the forced mode the required value of the flux linkage

the rotor defined by the bond)

see FIG. 6,

In the third zone of regulation, when the rotational speed Bbmie of the boundary level increases, determined by the condition

w, and) „

(36)

where Ci 0.5-1 is relative boundarygr

the rotational frequency, the stator voltage reaches its maximum value, and therefore the invariant control of condition (1) is carried out using an adaptive torque regulator 7 under the action of restriction (4) by decreasing 1 and the required torque M, reducing the flow-forming component stator current

. g.j

  i

SX

(37)

and reducing the amplitude of rotor engagement If D uj).

Increased rotational speed

at the outputs of the first 11 and fourth 14 blocks of nonlinearity of the voltage, increasing with increasing the voltage measured by the sensor 3 and the voltage that goes to the input of the second module 16 allocation module, is rectified and after conversion in the first block 11 of nonlinearity whose characteristic is given on

50 F 2, is fed to the second input of the controlled limiting unit 8.

F 2 is fed to the second input of the controlled limiting unit 8.

At the output of block 8 of the controlled limitation, the voltage U sets the required torque M decreases, as a result, the smaller the rotational speed and the higher the LM at the output of the first nonlinearity block 11. The voltage at the output of dividing unit 9 decreases, c.

21151532222

therefore, 6, e) is simultaneously reduced, and the amplitude of the flux linking moment-forming and flow-forming rotor drops (Fig. 6, e). The limiting I current component of the stator isx and i

sj the amplitude of the stator current ij decreases,

as shown in FIG. 6, d, while the phase shift E between the stator current and the rotor flux linkage increases above t45 ° due to the limiting stator voltage.

The increase in the phase shift E ,, the increase in the rotational frequency to the value is limited by the condition of achieving the maximum phase shift 1 190, at which the steady-state value of the rotor flux linkage is zero.

Thus, the device provides adaptive vector coupled torque control and rotor flow coupling by adaptive adjustment of the stator current phase and

co-component of stator current i

i.

 - is. is due to an increase in voltage at the output of the fourth non-linear unit 14 according to its characteristic shown in FIG. 5. For example, five times a threefold switching of the structure ™ of setting a reduction in the flow-control of the stator current phase,

The next component of stator current igy as the sum of interconnected synchronous with the code of the fourth block 14 of the non-phase cfg phase and the phase angle of shear, is fed to the input of the adder 19, the increase in energy and dynamic output of which results in a decrease in indicators is achieved -y U; sx setting the flow of the engine and the variant and optimal control of the engine torque in the entire required range of variation of the torque and rotation frequency, the maximum use of dynamic and

power system capabilities: voltage reduction Uis ", Ha output current converter - asynchronous

The differential adder 19 and at the input of the aperiodic link 17 leads to a decrease in the output voltage of the second 30 voltage, loss and heating of the motor 12 of the nonlinearity and reduction of the voltage.

the required amplitude of flux linkage; Inversion and optimal controller V (w). The moment is achieved by adaptive

The reduction of the output voltage of the auto-control in the dynamics and statics of the nonlinearity block 12 occurs — the degree of use of the magnetic circuit is more intense than the decrease in the voltage Ujsx of setting the torque-generating component of the stator current at the output of the first division block 9, due to

than the voltage U / jto of setting the control of interconnected actions on the phase constituting the synchronous frequency of the frequency and amplitude of the stator current with

increases with increasing frequency of rotation to. As a result of an increase in the controlled component of the synchronous frequency generator at the actual current limitations in the electric drive.

by the associated change in the torque and amplitude of the rotor flux linkage up to the deep saturation of the magnetic circuit, which is achieved by

using an adaptive torque controller.

The power indices increase the decay of the phase shift if 45 due to the increase in efficiency as a result of the absolute phase current of the stator changes the decrease in losses in all three zones c as the sum of the two components of their phase adjustment due to

mode close or coincident with

5 / s () EifCw) (39) with the minimum current mode in statics increasing the output power asynchronously, and with an increase in the rotation frequency of the lower motor both in the constant boundary level mode u) the synchronous phase moment and in the constant mode

. and the phase shift if the power increases (the boundary between which is more intensely rolling, the faster it grows in Fig. 2), as a result, the rotation frequency co., j increases neither the limiting moment (up to

With an increase in the rotational speed of 6-7-fold values) and the limiting

the required moment M decreases (Mn, speed with stator current limitations, stator voltage and total heating losses, including in range-i

M

eleven

M.,), Stator current amplitude

decreases (i s i, is Sij) (FIG.

6, e), and the amplitude of the rotor flux linkage decreases (Fig. 6, e). Ultimate

an increase in the rotational frequency to a value is limited by the condition for achieving the maximum phase shift 1 190, at which the steady-state value of the rotor flux linkage is zero.

Thus, the device provides adaptive vector coupled torque control and rotor flow coupling by adaptive adjustment of the stator current phase and

triple switching of the stator current phase control structure,

 voltage, loss and heat of the motor.

DIEGEL with current restrictions in the electric drive.

 control in dynamics and in statics the degree of use of the magnetic circuit

by the associated change in the torque and amplitude of the rotor flux linkage up to the deep saturation of the magnetic circuit, which is achieved by

using an adaptive torque controller.

Energy indicators are increased 231515322

speed control, value with c c l l

excitement losses in the absence of the required moment up to three orders of magnitude lower than the excitation losses in the known dynamic control systems of an asynchronous electric drive with constant rotor flux linkage due to a decrease in the initial value of the current-forming component of the stator current is up to the values normally accepted previously only for excitation currents of direct current motors with independent excitation, namely, to the level constituting The expression (9) is 5% of the rated motor current, and the excitation loss, proportional to the square of the current, is less than 0.3% of the nominal loss in the stator winding.

The dynamic characteristics of an asynchronous electric drive are increased by increasing the acceleration of the electric drive in start-up modes by ensuring maximum torque.

the stator with a limited stopping current of the stator current phase, the required motor; increasing the passband of the asynchronous electric drive by increasing the maximum achievable dynamic moment in the second control zone j and increasing the speed of torque build-up at low initial rotor flux coupling and low initial excitation current at a jump-like transition from the first control zone to the second zone can be increased due to the forma by 30-60%, and the moment-forming and flow-rate diasiruations of the speed regulation can disintegrate the stator current components and force the controlled state rail is the synchronous frequency and the current frequency encoder stator pa; bystrodeyst- increasing accelerations. dd VIA increase in speed in the third zone of regulation up from the boundary speed due to a smooth dependent increase in the phase shift between the current

50

ment, and the amplitude of the flux linkage of the rotor.

Thus, the maximum torque of the asynchronous motor, acceleration and bandwidth can be ij5-2 times as compared with the known asynchronous electric drives, for a long time, the moment of the asynchronous motor

Claims (1)

be expanded 2-4 times. Invention Formula The stator and the rotor flux linkage and ensuring maximum torque while limiting the stator voltage; an increase in the speed of working out the disturbing influences from the load due to the forcing of the stator current components and frequency and the increase as a result of this compensating torque of the engine (this increases the dynamic rigidity of the electric drive) 55 An AC electric drive containing an asynchronous motor connected by stator windings to the outputs of a pulse current converter made with control inputs for frequency and for orthogonal stator current components, a rotational speed sensor mounted on an asynchronous motor shaft, serially connected speed setting unit, reference element and proportional to the integral speed controller, while the other input of the reference element is connected to the output of the frequency sensor 24 The heating of the asynchronous motor is reduced due to a sharp decrease in the initial excitation loss, a decrease in the green losses in the stator winding and the stator current in the established modes by minimizing the stator current for a given motor torque; decrease in the most probable; severely operating modes of the engine total heating losses in the engine, which are close to the minimum possible 1 in the whole range of torque and speed control. Expansion of the speed control range is achieved by reducing the uneven rotation rate and speed errors when the load changes at a lower speed uimnH as a result of fast-acting stator current phase and providing a phase shift between the stator current vectors and the rotor flux ratio (lower speed control range decreases, decreases the minimum possible WMHH speed at a given error x-speed, increasing the maximum speed by adaptive adjustment phase of the stator current, the required mo can be increased by 30-60%, and the speed control range can ment, and the amplitude of the flux linkage of the rotor. Thus, the maximum torque of the asynchronous motor, acceleration and bandwidth can be ij5-2 times as compared with the known asynchronous electric drives, for a long time, the moment of the asynchronous motor phase of the stator current, the required mo can be increased by 30-60%, and the speed control range can be expanded 2-4 times. Invention Formula phase of the stator current, the required mo can be increased by 30-60%, and the speed control range can An AC electric drive containing an asynchronous motor connected by stator windings to the outputs of a pulse current converter made with control inputs for frequency and for orthogonal stator current components, a rotational speed sensor mounted on an asynchronous motor shaft, serially connected speed setting unit, reference element and proportional to the integral speed controller, while the other input of the reference element is connected to the output of the frequency sensor rotation 25 o tl and h u u and u with that, in order to increase energy and dynamic performance by increasing acceleration, reducing losses and heating the engine, increasing engine torque and power, and expanding the speed control range, an adaptive torque regulator, complete with two inputs and three outputs, and equipped with a unit was introduced controlled constraint, two division blocks, four nonlinearity blocks. themes and connected to the output of the second unit nonlinearity connected by an input with an aperiodic link output, output of the first dividing unit is connected to the input of the third nonlinearity unit connected to the input of the first endowment block of the module, the inputs of the first and fourth nonlinearity blocks are connected to each other and connected to the output of the second block of the module The input of which is combined with the second input of the first adder and forms the second input of the adaptive controller momendvum blocks of the module slot, aperi-15 ta, connected to the sensor output by a clock link and two adders, wherein the input of the controllable limiting unit, which forms the first input of the adaptive torque controller, is connected to the output of the proportional-integral speed controller, the output of the controlled limitation unit is connected to the input of the divisible first dividing unit, and its control input - to the output of the first nonlinearity block; output of the first division block is connected to the input of the divisible second division block connected to the first input of the first adder; the inputs of the dividers dividers are interconnected 30 rotational speeds, the output of the fourth nonlinearity block and the output of the first selection block of the module are connected to the corresponding inputs of the second adder connected to the Aperiodic link input, and the outputs of the first and second adders and the output of the first division block forming the first, second and third outputs of the adaptive controller, respectively torque are connected respectively to the control inputs for the frequency and for the orthogonal components of the stator current of the pulse current converter. & M 0.5n MO Const P2 CQnsf cJo2 (0o FIG 2 532226 and connected to the output of the second unit nonlinearity connected by an input with an aperiodic link output, output of the first dividing unit is connected to the input of the third nonlinearity unit connected to the input of the first endowment block of the module, the inputs of the first and fourth nonlinearity blocks are connected to each other and connected to the output of the second block of the module The input of which is combined with the second input of the first adder and forms the second input of the adaptive torque controller 5, connected to the output of the rotational speed sensor, the output of the fourth nonlinearity unit and The output of the first selection module of the module is connected to the corresponding inputs of the second adder connected by an output to the input of the aperiodic link, and the outputs of the first and second adders and the output of the first division block, respectively forming the first, second and third outputs of the adaptive torque controller, are respectively connected to the control inputs for the frequency and for the orthogonal stator current components of the pulse current converter. max U- u.  i. i, - / An. i ym / B-ii . "  .Ji j one y / TTflX fcJo 5 D «« ГЖ