SU1584057A1 - Device for shaping signals for controlling ac electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in AC electric drives. The purpose of the invention is simplification. The device contains phase output 1, 2 and phase auxiliary 3, 4 operational amplifiers with resistors 5–8 in the feedback circuit of each amplifier, phase inverters 9, 10 voltage, phase scale resistors 11, 12, four groups of input resistors 13 - 16 and four groups of diodes 17-20. The device allows forming instantaneous control signals of an AC electric drive with simplicity of the apparatus by replacing the operation of multiplying a DC signal with a harmonic signal with a controlled trimming operation of this harmonic signal. Cesky signal DC signal. 2 Il.

Description

The invention relates to electrical engineering and can be used in AC electric drives.

The purpose of the invention is simplification.

FIG. 1 is a schematic diagram of the device; in fig. 2 - diagrams on the operation of the device.

The device for generating AC drive control signals includes phase output 1, 2 and phase auxiliary 3, 4 operational amplifiers with resistors 5-8 in the feedback circuit of each operational amplifier, phase inverters 9 and 10 voltage, phase scale resistors 11 and 12 , four groups of input resistors 13-16 and four groups of diodes 17-20.

The anodes of the first and third diodes and the cathodes of the second and fourth diodes of each group of diodes are combined and connected to the inverse inputs of the phase auxiliary 3, 4 and phase output 1, 2 operational amplifiers. In addition, phase scaling resistors 11 and 12 are also connected to inverse inputs of phase output operational amplifiers 1 and 2, respectively. The cathodes of the first h of the third diodes of the first group of diodes 17 are connected to the third resistors of the third 15 and first 13 groups of input resistors, respectively, and the cathodes of the first and The third diode of the second group of diodes 18 is connected to the third resistors, respectively, of the fourth 16 and second 14 groups of input resistors.

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The anodes of the second and fourth diodes of the first group of diodes 17 are connected to the fourth resistors, respectively, of the third 15 and first 13 groups of input ™ resistors, and the anodes of the second and fourth diodes of the second group of dioses 18 to the fourth resistors of the corresponding fourth groups resistors, -JQ

The cathodes of the first and third diodes of the third group of diodes 19 are connected to the first resistors of the third 15 and first 13 groups of input resistors, respectively, and the cathodes of the first third to 15 diodes of the fourth group of diodes 20 are connected to the first resistors of the fourth 16 and second 14 groups of input resistors, respectively. The anodes of the second and fourth diodes of the third 20 group of diodes 19 are connected to the second resistors, respectively, of the third 15 and first 13 groups of input resistors, and the anodes of the second and fourth diodes of the fourth group of diodes 20 25 are connected to the second resistors four-if | 6 and the second 14 input resistor groups. In addition to that, the cathode r «.- and the third diodes of the first l of the second 13 groups of diodes are connected, respectively, to the second anodes to the fourth diodes of the third 19 and fourth fours of the diode groups.

The anodes of the second and fourth diodes of the first 17 and second 18 groups of diodes are connected respectively to the cathodes of the first and third diodes of the third 19 and fourth 20 groups of disds. SosPiP d the first and second pins of the first 12 and second 14 groups of Q input resistors connected to the input 21 of the assignment of the reactive component of the third 15 and fourth 16 groups of the third and 45 x resistors are combined and sudkl.che-, HL to the input 22 of the assignment of the active current connection. The free output of the second resistor of the second 14 and the third resistor of the third 15 §g input resistors are connected to the voltage across the phase inverter 9 connected to the first input 23 of the harmonic function, to which the free leads of the third resistor of the second 14 and fourth resistor of the third 15 are also connected. c ,, input resistors. The free pins of the fourth resistors are r-13 and

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the fourth volume of the inverter 1, the second, function of the output phase loaders in the CTE amplifier. but ram i j and

On the voltage of the reactive current, si input 23, cos and 24 s 1 and no phase

Arrange way.

Functions of the so-called transfer ratio:

x 1 x

where u and

In the case of setting the “z” signal of sig.k from s.

Realize a resident with a measure of the Forma At the same time, the resistor is

 sxiP d ccsF ct

Fourth 1C1 groups of BRANCH resistors are combined, and through the base inverter 10, the voltages are connected to the second input 24 of the harmonic function, to which the free terminals of the third resistors of the 13th and fourth 16th groups of input resistors are also connected. In this case, the outputs of the phase auxiliary operational amplifiers 4 and 3 are connected to the corresponding STE. but to the phase scale resistors I J and 12.

Figs 1 and 2 denote the U and UQ voltages of the inputs 21 and 22 of setting the reactive and active components of the current, sinPo {is the voltage of the first input 23 of the harmonic function, cosP d is the voltage of the second input 24 of the harmonic function, 1 and wic output voltages of the phase output operational amplifiers 1 and 2.

The device works as follows.

The functional purpose of the device is the hardware implementation of the so-called direct coordinate transformations described by the expressions:

be x 1 -aa. sinP oi + U2-cosP "; And LV cosP + UD-sinPo (,

sxiP d ccsF ct

where U and U, are the DC signals;

and

 sxiP d ccsF ct

- signals that are harmonic functions of constant amplitude.

In the device, the above transformations are performed approximately for the replacement of the operation of multiplying the DC signals by the hormone-relieving signal by the operation of a controlled cut of this harmonic signal by the DC signal, i.e. at the same time, the top of the harmonic signal is cut off at the level of the DC signal.

The implementation of the approximate signal multiplier is considered by the example of the formation of the signal U cosP.o. The ratio of the ratings of all the resistors of the first 13, second 14E third 15 and fourth 16 groups of input resistors and resistors

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5-8 in the feedback and scale resistors 11 and 12 are two. When applying to the second input 24 signal cosP d. (consider its positive polarity), and the input 21 is the signal UD in the time intervals when U D cosPc /, the fourth diodes of the first 17 and third 19 groups of diodes are open, and the third diodes of the same groups of diodes

closed and the voltage at the output of the phase output op amp 1 U

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equal to voltage signal

cosP t (at the selected ratio of resistors. In the time interval when UD cosP оG, the third and fourth diodes of the third 19 group of diodes are open, and the third and fourth diodes of the first group 17 are closed, and the voltage is equal to the voltage of 11 When the polarity of the signal cosP d is changed in time intervals when U jj (cosP, the fourth diodes of the first 17 and third 19 groups of diodes are open, the third diodes of those groups are closed, and the voltage U6MX1 is equal to the signal voltage cosPal, In the time interval, when Uj, | cosP d I, the third and fourth diodes of the first 17 The diode arrays are open, and the third and fourth diodes of the third diode group 19 are closed, and the voltage U 6l (x 1 is equal to the voltage UD and is limited at this level. Thus, by changing the conductivity of the corresponding diodes as a result of comparing the DC signal and of the signal, which is a harmonic function, an approximate multiplication of these signals occurs, and the multiplication of signals occurs in all four quadrants of the coordinate system with a constraint, since the amplitude of the signal U cosP and cannot exceed the amplitude of the signal ala cosP o /. The signal U E cosP d obtained by approximate multiplication is shown in FIG. 2a The amplitude of the first harmonic of the signal U-p cosP ol is equal to the signal Uj, and coincides in phase with the signal cosP о (i.e. the approximate multiplication in the device is inertia-free. In addition to the first harmonic, the signal Ujj-cosP d. Contains the highest odd harmonics - the third, fifth, seventh, and so on, which depend on the magnitude of the signal Ujj and determine the multiplication error.

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The signals Ue sinP a (, U-cosP d., U d sinPo are generated in a similar way by changing the conductivity of the respective diodes as a result of comparing the DC signals and signals that are harmonic functions (Fig. 2a and 26). In addition , shows the resulting control signals and theirs, obtained by adding the corresponding signals.

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From the principle of the device

It follows that replacing the operation of multiplying a DC signal with a harmonic signal with a controlled trimming operation of this harmonic signal with a DC signal greatly simplifies the device.

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Claims (1)

Invention Formula A device for generating AC drive control signals comprising phase output and phase auxiliary operational amplifiers with resistors in the feedback circuit of each operational amplifier, phase voltage inverters, phase scale resistors, four groups of input resistors and four groups of diodes, the anodes of the first and The third diodes and cathodes of the second and fourth diodes of each group of diodes are combined and respectively connected to the inverse inputs of the phase auxiliary and phase outputs one operational amplifiers to which the phase scale resistors are connected, the cathodes of the first and third diodes of the first and second groups are connected to the third resistors of the third, first, fourth and second groups of input resistors, respectively, and the anodes of the second and fourth diodes of the same groups are connected to the fourth resistors of those the same groups of input resistors, the cathodes of the first and third diodes of the third and fourth groups are connected to the first resistors of the third, first, fourth and second groups of input resistors, respectively, and the anodes of the second and fourth diodes of the same groups are connected to the second resistors of the same groups of input resistors, characterized in that, for the purpose of simplification, the cathodes of the first and the third diodes of the first and second groups are connected respectively to the anodes of the second and fourth diodes of the third and fourth groups, the anodes of the second and fourth diodes of the first and second groups to the cathodes of the first and third diodes of the third and fourth groups, respectively; a group of input resistors are combined and connected to the input of the reactive current component, the free terminals of the first and second resistors of the third and fourth groups of input resistors are combined and connected to the input tribute to the active component of the current, the free conclusions of the fourth resistor of the second and third resistors of the third group of input resis SAZAI , The tori are connected and, via a single phase voltage inverter, are connected to the first input of a harmonic function, to which the free terminals of the third resistor of the second and fourth resistors of the third group of input resistors are connected, the free terminals of the fourth resistors of the first and fourth groups of input resistors are connected through another phase in ™ ver; The in voltages are connected to the second harmonic function, to which the free terminals of the third resistors of the first and fourth groups of input resistors are also connected, while the outputs of the phase auxiliary operational amplifiers are connected to the phase scale resistors.