SU1575285A2 - Device for determining coordinates of induction motor in controllable electric drive - Google Patents

Abstract

The invention relates to electrical engineering, namely to electric drive control systems. The aim of the invention is to improve the accuracy of determining the coordinates of the asynchronous motor in static and dynamic modes of operation. A device for determining the coordinates of an asynchronous motor in an adjustable electric drive, containing sensors of 2 stator phase currents and sensors of 4 stator phase voltages, introduced two multiplication units 13,14, an adder and a relay element 12, the output of which is connected to the additional inputs of calculating component 6 the flux linking vector of the rotor and the block 7 for calculating the components of the stator current vector. Each of the indicated blocks 6,7 is supplied with two additional multiplication blocks. This provides the formation of an additional variable signal, the deviation of which from zero is used to compensate for the divergence of parameters in the system, thereby increasing the accuracy. 3 il.

Description

one

(61) 1399882

(21) 4413663 / 24-07

(22) 21-10 '88

(46) 30 „06„ 90. Bksh. No. 24

(71) Ivanovo Energy Institute named after VoIoLenin

(72) N.L.Arkhangelsky, B „SoKurnyshev, S o K“ Lebedev, V0VoPikunov

and S A.Rubtsov

(53) 621.316.7 (088.8)

(56) USSR Author's Certificate No. 1399882, Clo H 02 P 5/402, 19860

(54) DEVICE FOR DETERMINING COORDINATES OF AN ASYNCHRONOUS MOTOR IN A REGULATED ELECTRIC DRIVE

(57) The invention relates to electrical engineering, namely to electric drive control systems. The aim of the invention is to improve the accuracy of determining the coordinates of an induction motor in static and dynamic modes of operation B a device for determining the coordinates of an induction motor in an adjustable electric drive containing sensors 2 stator phase currents and sensors 4 phase stator voltages, two multiplication units 13, 14 are introduced, an adder and a relay element 12, the output of which is connected to the additional inputs of the calculation unit 6 Substituting constituents vector potoko- clutch rotor and calculating unit 7 constituting the stator current vector. Each of the 6, 7, ukhannyh blocks is equipped with two additional multiplication blocks. In this case, an additional variable signal is generated, the deviation of which from zero is used to compensate for the discrepancy of parameters in the system, thereby increasing accuracy, 3 sludge

/ J

cl

1U

Pue.f

The invention relates to electrical engineering, in particular, to devices for determining the coordinates of an induction motor, can be used in adjustable asynchronous electric drives and is an improvement of the invention according to avt.

The purpose of the invention is to improve the accuracy of determining the coordinates of an induction motor in an adjustable electric drive in static and dynamic modes of operation

Fig. 01 is a functional diagram of the device for determining the coordinates of an induction motor in an adjustable electric drive; Fig. 2 is a block diagram of the calculation of the components of the rotor flux linkage vector; on figs - block diagram of the calculation of the components of the stator current vector

A device for determining the coordinates of an asynchronous motor 1 (Fig. 1 contains sensors 2 stator phase currents connected by outputs to the inputs of current conversion unit 3, sensors of 4 stator phase voltages connected by outputs to inputs of voltage conversion unit 5, vector components calculating rotor flux linkage, equipped with five inputs, block 7 for calculating the stator current vector components, equipped with nine inputs, two elements 8 and

9Comparison, three relay elements

10-12, two multipliers 13 and 14 and an adder 15 o

The first pair of inputs of the calculator 6 components of the rotor flux linkage vector is connected in phases with the first pair of inputs of the calculator 7 components of the stator current vector component, with the first inputs of the corresponding comparison elements 8 and 9 and connected to the outputs of the current conversion unit 3, the second pair of inputs are combined phase with the second pair of inputs of block 7 and connected to the outputs of the first 10 and second 11 relay elements, an additional five clock output of block 6 is combined with an additional ninth input of block 7 and connected to the output of the third relay Foot member 12, the outputs of unit 6 are connected to the third pair of input unit 7, the fourth pair of inputs of which is connected to the outputs 5 ka blo converting stator voltages, and outputs the block 7 are connected to second inputs of respective elemen10

five

20

25

thirty

35

40

45

50

55

Commands 8 and 9, the outputs of which are connected to the inputs of the first 10 and second 11 relay elements. The outputs of the first 10 and second 11 relay elements are connected to the first inputs of the respective first 13 and second 14 multipliers, the second inputs of which are phase-wise connected to the outputs of the vector computation block. rotor flux linking, and outputs - respectively to the first and second inputs of the adder 15, the output of which is connected to the input of the third relay element 12 "

The computation unit 6 of the rotor flux-link vector components () contains two adders 16 and 17, two aperiodic links 18 and 19, the outputs of which form the outputs of the specified block, and the inputs are connected to the outputs of adders 16 and 17, respectively, two pairs of scale elements 20 and 215 22 and 23, the inputs of which form the first and second pair of inputs of the block, and the outputs are connected to the first and second inputs of adders 16 and 17, respectively, to the third inputs of which are connected the outputs of multipliers 24 and 25, the first inputs of which are combined and form an additional fifth input unit 6, the second inputs of the multipliers 24 and 25 of each phase are connected to the outputs of aperiodic links 18 and 19, respectively I

Block 7 of calculating the stator current vector components (Fig 3) consists of two adders 26 and 27, two aperiodic links 28 and 29, the outputs of which form the outputs of the specified block, and the inputs are connected to the outputs of adders 26 and 27, respectively, four pairs of scale elements 30 and 31, 32 and 33, 34 and 35, 36 and 37, the inputs form the first, second, fourth and third pairs of inputs of the block 7, respectively; the outputs of the scale elements 30, 32, 34 and 36 and 31, 33, 35 and 37 are connected to the first, second, third and fourth inputs of adders 26 and 27, respectively, to the fifth inputs of which but connected to outputs of the multipliers 38 and 39, the first inputs of which are combined to produce an additional input unit 7, and second inputs are combined with each phase input of said third pair of unit ,,

A device for determining the coordinates of an induction motor in an adjustable electric drive works as follows.

The current conversion unit 3 and the voltage conversion unit 5 convert the phase currents and voltages from the respective sensors 2 and 4 into components

tel; - additional

variables; (and is a variable parameter.

The projections of the calculated rotor lateral coupling vector are formed in block 6, which implements the following differential equations:

dy

dt

(H

RRW

,

Lrt

 Rrf

  Vm

ar Ц 4V ТГ + H4-V

(7) The components of the stator current vector

I5of, ISAi, obtained at the output of current conversion unit 3, and the components of Igft sFormiR0831 ™ 6 at the outputs of block 7, are compared using comparison elements 8 and 9 The comparison results affect relay Elements 10 and 11, from the outputs of which receive pulse signals X, L X

V

time-modulated, performing the function of control actions in the control loop:

generalized current vectors IS (I5. and the stresses VSe /, U5 / a of the stator in the Cartesian coordinate system o (, / 3 fixed relative to the stator of the induction motor

The projections of the calculated current vector of the stator 1 ,, I are formed in block 7, which implements the following differential equations:

)

(eight)

l / 3 - x0 sign cis / a-1 ;, (9)

where X 0 is the amplitude of control actions

In the steady state operation of the device, when its free movement is completed, the average values of the variable. ; (YU)

40 W-ftv.w (ID

In order to implement the following mode, the direction of the rotor flux vector is added to Eqs. (4) - (7)

45

f ° 1 G

O and J J (12)

where p is a variable parameter, which

vanishes in the set mode

According to equations (10) and (11), the vectors X and if are orthogonal. But the condition of orthogonality is satisfied only in one case, when. As (L 4 0, other variables enter into equations (4) - (7):

x "J;

i- CL +,

(13) (14)

which are not orthogonal to the rotor attachment vector.

Thus, the condition p 0 corresponds to the orthogonal mutual arrangement of the vectors X and c. In this case, the condition

X - X, (15)

which indicates the implementation of equalityQ

VJ-V

(sixteen)

The multipliers 13 and 14, the adder 15 and the relay element 12 perform barely 1V

blowing operation:

F- Lxrf + 17

where p is a pulse signal characterizing the degree of deviation of the vectors X and Of ft from the orthoton positioning Equation (17) is the scalar product of two vectors X and Y%, it vanishes in the case of the orthogonal arrangement of these vectors, thus condition

- four

x-

Os

(18)

The variables Xj, X create such a device motion control vector that the tracking of the stator current vector and the direction of the rotor coupling vector is carried out in all modes of operation of a real asynchronous motor so that in each channel the feedback is negative at any moment temporarily

The signals X ,, Xd, (l vary with a frequency much more than the voltage and current of an induction motor in an adjustable drive. In addition, the high switching frequency ensures a small free movement systemically

Thus, the introduction into the proposed device of an adder, two multipliers, a relay element, two multipliers in the block for calculating the components of the rotor flux vector of the rotor and the formation of their connections with the rest of the circuit elements provide for the formation of an additional variable signal whose deviation from zero. used to compensate - the discrepancy of parameters in the system, so that in comparison with the known

Q

J5

20

25

30 35

40, 45

50 55 the device increases the accuracy of determining the coordinates of the asynchronous motor

Claims (1)

Invention Formula A device for determining the coordinates of an asynchronous motor in an adjustable drive according to AvtoSv0 No. 1399882, characterized in that, in order to improve the accuracy of determining the coordinates of the asynchronous drive in static and dynamic modes of operation, an additional adder, an additional relay element, and two multipliers, a unit for calculating vector components are introduced the rotor flux linkage is equipped with two multipliers, the first inputs of which are combined and form an additional fifth input of the specified block, the second inputs of the decree The multipliers are connected to the outputs of the corresponding aperiodic links, and the outputs are to the additional inputs of the corresponding adders of the calculator of the components of the rotor flux linkage vector, the calculator of the components of the stator current vector is equipped with two multipliers, the first inputs of which are combined and form the additional ninth input of the specified block, the second inputs of these multipliers are connected in phase with the third pair of inputs of the calculator of the components of the stator current vector, and the outputs of the multipliers are connected to Additional inputs of the corresponding adders of the calculator of the stator current vector components, wherein the first inputs of the multipliers entered into the specified device are connected in phase with the second pairs of inputs of the calculating blocks of the component vectors of the stator and the rotor flux linkage and connected to the outputs of the corresponding relay elements, the second inputs of the entered multipliers connected to the outputs of the computation unit of the rotor flux linking vector components, the additional fifth input of which and the additional The eighth input of the calculator of the stator current vector components is combined and connected to the output of an additional relay element connected by an input to the output of an additional adder. Compiler A Ж Zhilin RigJ Editor A 0 0gar Tehred M. DidykKorrektor V.Kabatsiy Order 1790 Circulation 458 VNIIPI State Committee for Inventions and Discoveries at the State Committee for Science and Technology SASSR 113035, Moscow, Zh-35, 4/5, Raushsk nab. Production and publishing: Patent Combine, Uzhgorod, st. Gagarin, 101 FIG. 2 Subscription