RU18809U1 - DEVICE FOR REGULATING VOLTAGE UNDER LOAD - Google Patents

Abstract

A device for regulating voltage under load, containing a supply double-winding transformer, the primary winding of which is connected to the supply network, and between the output terminals of its secondary winding and the corresponding terminals of the electrical receivers, a circuit containing a series connection of "n" primary windings (where n = 1, 2, ...) transformers, respectively, "n" transistor-thyristor modules with thyristor key blocks and a functional block that includes a converter, from the output of which to the system processor According to his command, the program control signals the magnitude of the phase angle of the load, the output terminals of the program control system are connected via output stage blocks to the control electrodes of the thyristor switches of transistor-thyristor modules, characterized in that when creating a circuit for simultaneously supplying a group of power receivers using circuits similar to the above, the terminals of the secondary winding of the supply double-winding transformer are connected to the corresponding terminals of each of the power receivers the joints, and the clamps and taps of the secondary windings of the transformers of all transistor-thyristor modules through thyristor keys are connected with the possibility of switching between them, or counter-matching with the respective primary windings of these transformers and parallel to their output terminals of the secondary winding of the supply double-winding transformer, and the functional unit includes current and voltage sensors with the possibility of generating by the converter signals that carry information as a phase

Description

DEVICE FOR VOLTAGE REGULATION UNDER LOAD (USEFUL MODEL)

The solution relates to power electronics and electrical engineering and can be used for wide-range and small-stage voltage regulation under load.

A device is known for regulating voltage under load, comprising a matching (supply) double-winding transformer, the primary winding of which is connected to the supply network, and between the output terminals of its secondary winding and the corresponding terminals of the electrical receivers there is a circuit containing a series connection of n primary windings (where,, 2, ...) transformers, respectively, transistor-thyristor modules with thyristor key blocks and a functional block containing instantaneous value sensors of current and voltage at the terminals of power receivers, as well as a semiconductor converter, from the output of which to the device’s software control system, at its command, signals about the voltage and phase angle of the load are received, the output terminals of the program control system are connected to the thyristor control electrodes through output stage blocks keys of transistor-thyristor modules (see Russian patent No. 2119229, class N 02 M 5/12, G 05 F 1/253, 1998 / prototype /). predetermined level of electric power removed from the output terminals

device when regulating the voltage in the direction of its reduction, requires large expenditures of active materials for the manufacture of the device and is characterized by increased energy losses in the elements of the device during its operation. This is due to three main reasons. One of them is that with a known device, when the voltage at its output terminals decreases, it is necessary to proportionally reduce the electric power of the load that is transmitted to the electrical receivers. Otherwise, the current increases along the windings of the supply double-winding transformer above the nominal value and the latter fails. Another reason is that in the known device, a double-winding power transformer is used to power only one or a limited number of power receivers that can be connected in parallel. Therefore, the specific consumption of active materials for the manufacture of the transformer and the loss of electricity in its windings during operation increase. The third reason is the lack of a known device, in comparison with the claimed technical solution, the possibility of optimal control of the voltage levels at the terminals of individual power consumers within their group at different intervals of operation time. This does not allow for a minimum of energy losses in the elements of the device and the minimum cost of active materials for the manufacture of transformer equipment of the device

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generally. In addition, with the known device, the clamps of the secondary windings of the transformers of all transformer-thyristor modules are connected directly to the clamps of the supply network. The voltage level of the supply network is 10 kV and above. Without using a step-down transformer, it is not possible to perform thyristor switches at such a high voltage level. Therefore, the cost of active materials for the manufacture of a known device, and therefore the loss of electricity in its elements increase significantly. For example, the use of a known device for regulating voltage in the range of 0-100% of its nominal value and while maintaining at a constant nominal level the magnitude of the electrical power received from the terminals of the device, at least for the range of 25-100% of voltage regulation, leads to an increase in the overall power of the transformer equipment of the known device compared with the above-mentioned electric power more than five times. Another example of the use of the known device (for regulating the voltage in the range of 0-100% of the nominal value and maintaining the current consumed by the electric consumers at a constant nominal level) gives an increase in the overall power of the transformer equipment of the known device compared to the largest consumed electric power of more than 1.5 times. 3

The objective of the proposed technical solution is to expand the functional capabilities of the device for regulating voltage under load and reduce the consumption of active materials for its manufacture.

The technical result consists in the fact that it becomes possible to use the same supply double-winding transformer for power supply and voltage regulation simultaneously at the terminals of a group of power consumers according to individual laws for each power receiver of the group. The consumption of active materials and the cost of manufacturing the transformer equipment of the device, as well as the operating costs of its use, are reduced more than one and a half times.

This technical result is achieved by the fact that in the device for regulating voltage under load, containing a supply double winding transformer, the primary winding of which is connected to the supply network, and between the output terminals of the electrical receivers there is a circuit containing a series connection of “n primary windings (where,, 2 ,. ..) transformers, respectively, “n thyristor transformer modules with thyristor key blocks and a functional block (block 15 of the prototype device circuit), which includes a converter, with the output of which to the processor of the program control system at his command signals are supplied about the magnitude of the phase angle of the load, the output terminals of the program control system are connected to the control electrodes of the thyristor keys through the blocks of the output stages

transistor-thyristor modules according to the proposal, when creating a scheme for the simultaneous supply of a group of electrical receivers using circuits similar to the above, the terminals of the secondary winding of the supply double-winding transformer are connected to the corresponding terminals of each of the electrical receivers of the group, and the terminals and taps of the secondary windings of the transformers of all transformer-thyristor modules through thyristor keys are connected with the possibility of their switching among themselves, or counter-consonant with respect to the corresponding primary windings of these transformers and connecting them in parallel to the output terminals of the secondary winding of the supply two-winding transformer, and the functional unit includes current and voltage sensors and is configured to generate signals that carry information about both the magnitude of the phase angle of the load and the voltage values, current and active power, while the number of functional blocks is increased to the number of power consumers connected to the power supply circuit, and the number of output stages of the system is program control selected appropriate number of transistor-thyristor modules.

Figure 1 shows a diagram of one of the variants of the device containing in its composition a group of power consumers that receive electricity from this device; shown is a group containing two separate power consumers, which cannot be connected in parallel and receive electricity from one and

the same input terminals of the supply network; figure 2 is a variant of the circuit diagram of the transistor-thyristor module of the device; in Fig. 3 - vector topographic diagrams explaining the process of regulating voltage at the load; figure 4 - diagram of the functional block of the device.

The device (Fig. 1) contains a supply double winding transformer 1 with primary 2 and secondary 3 windings, between the output terminals ai, bi, Ci of the secondary winding 3 of the supply transformer 1 and the input terminals of each of the power receivers 4 and 5, the primary windings are connected in series with each other, respectively 6 , 7 and 8, 9 of transformers 10, 11 and 12, 13 of the corresponding transistor-thyristor modules. A variant of the complete circuit design of the transistor-thyristor module in figure 1 is limited by the dashed line I and is shown in figure 2. The terminals and taps of the secondary windings 14, 15 and 16, 17, respectively, of the transformers 10, 11 and 12, 13 of these modules are connected to the output terminals ai, bi, Ci of the secondary winding 3 of the supply transformer 1 through the thyristor switches of the respective blocks 18, 19 and 20, 21 Schematic diagrams of all thyristor keys of the device are the same. As an example, in Fig. 2, a dashed line shows a schematic diagram of one embodiment of a thyristor key of block 18 (position 18.1). Instead of thyristors, other high-current elements that are technically equivalent in terms of function can be used as active elements (thyristor switches) (for example, triacs.

mechanical contacts with arc quenching in vacuum, etc.). The program control system 22 of the device (indicated by a dotted line) comprises a read-only memory unit 22.1, a processor unit 22.2, functional blocks 23, 24 (shown in dashed lines in FIG. 1), as well as a control unit 25 and output stage blocks 26, 27, 28 and 29 by the number of transistor-thyristor modules used in the device. To connect the supply network to the device, terminals A, B, C are used. Function blocks 23, 24 generate signals that carry information about the phase angles of the load of the electrical receivers, as well as the values of voltage, current and power at their terminals. They contain sensors of instantaneous values of current consumption i, voltage and at the terminals of individual power consumers, as well as a semiconductor converter F. From the output of the latter to the device software control system, at its command, the above signals are received. The device functional blocks is illustrated using figure 4, where they are also, as in figure 1, highlighted by a dashed line (position 23, 24). Blocks 26, 27 and 28, 29 generate control pulses with the help of which certain thyristor switches are closed and opened in order to change the connection scheme of the secondary windings of transformers 6, 7 and 8, 9.

Figure 2 shows a variant of the circuit diagram of one of the transistor-thyristor modules, which explains the switching of the windings of the transformers 10, 11 and 12, 13. Figure 2 is a fragment of figure 1, which is highlighted by dashed line I. By switching on

certain thyristor keys of blocks 18, 19 and 20, 21 clamps and taps

the corresponding secondary windings are connected in various versions, both between themselves and to the terminals of the secondary winding 3 of the supply transformer 1. For these purposes, several groups of groups are used in each thyristor switch block (Fig. 2 shows block 18). Certain thyristor switches 18.1, 18.3, 18.5, 18.8, 18.10, 18.12 of block 18 from the first group are turned on when it is necessary to reduce the voltage at the output terminals a2, b2, C2 by a certain discrete value compared to its value at the input terminals s, bi, Ci transistor-thyristor module. When it is required to increase the voltage at the mentioned terminals a2, b2, C2, then turn on the thyristor switches, for example 18.2, 18.4, 18.6, 18.7, 18.9, 18.11 of block 18 from the composition of their second group. The thyristor keys 18.13, 18.14, 18.15, 18.16, 18.17, 18.18 of the third group are used to connect the clamps and taps of the secondary winding to each other in order to obtain various options for its connection scheme. In the particular case, when there is no need to change the voltage at the output terminals a2, b2, C2 of the transistor-thyristor module relative to that at its input terminals ai, bb Ci, then certain thyristor switches are included exclusively from the composition of their third group. A schematic diagram of one embodiment of thyristor switches is shown by a dashed line (position 18.1). The input terminals of each of the power receivers 4 and 5 are indicated in Fig. 1, respectively, az, b3, c3 and a, 4, a. The mentioned terminals for functional blocks 23 and 24, respectively, are output

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clamps. As input terminals for these blocks, the terminals az, b3, c3 and hell, b4, c4 are used (Fig. 1).

Fig.Z contains vector topographic diagrams, which

correspond to various full-phase operating modes

transistor-thyristor modules. According to FIG. 3, possibly 9

full-phase modes of operation, which have conditional names Mode

1, Mode 2, ..., Mode 9. To provide these operating modes in

according to figure 2 included certain thyristor keys from

their various groups. For example, the mode of operation with a conditional name

Mode 1 is obtained by turning on the thyristor keys 18.13, 18.14.

18.17, 18.18 exclusively from the third group. Modes such as Mode 2,

Mode 3, ..., Mode 5 are provided through the use of parts

thyristor keys from the first and third groups. Other operating modes

Mode 6, Mode 7, ..., Mode 9 obtained by turning on some

thyristor keys from the second and third groups of them. Specific

thyristor key numbers to ensure the above

full-phase operating modes of transistor-thyristor modules

shown in Fig.Z. Analysis of diagrams of various operating modes shows

to reduce or increase the output voltage, for example

line voltage Ua2b2 relative to the corresponding input

Uaibi line voltage in almost equal steps. According to

figure 1 between the input terminals az, bz, Cz of a specific power 4

and output terminals ai, bi, Ci of the winding 3 of the supply transformer 1

Therefore, the device allows to obtain a three-phase voltage level at the terminals of each power receiver from their group. The voltage is regulated within 0-100% of the nominal value in small steps of about 1.25%. If an electric receiver, for example an electrolyzer for producing non-ferrous metal, requires direct current electricity, then the number of DC voltage levels at its terminals is increased several times. To do this, the input clamps of the rectifier bridges, from which the above-mentioned electrolyzers receive electric power, are supplied with an alternating voltage regulated in magnitude, not only by using the above-mentioned full-phase operation modes. In addition, they use a large number (87 such modes are established) of non-phase modes of operation of transformer-thyristor modules. The latter are implemented by selecting various options (87 pieces) of the non-phase connection of the secondary windings 14 or 15, 16 or 17 of the transformers 10 or 11, 12 or 13, respectively, to the output terminals of the winding 3 of the supply transformer 1.

Figure 4 shows a variant of the circuit of the functional block 23, which explains its device and its functions. Figure 4 represents fragments of figure 1, which are highlighted by dashed lines (positions 23, 24). By sequentially connecting between the corresponding input az, bz, sz and output az, bz, sz terminals of the block 23 of the primary winding of the current transformer 23.1, a signal is obtained about the instantaneous value of the current consumed by the power receiver 4

. This signal is removed from the terminals of the secondary winding of the current transformer 23.1 and fed to the input of the semiconductor converter 23.3. In addition, the input terminals of the Converter 23.3. a signal is supplied from the secondary winding of the voltage measuring transformer 23.2. This signal corresponds to the value of the instantaneous voltage value at the input terminals of the power receiver 4. Converter 23.3, using instantaneous values of current and voltage (i and u) as input, generates signals in accordance with the following functional dependences F (used

typical analog-to-digital conversion schemes):

(u); ((and, i); (1); (U, I, (p)}.

Signals about the values of the effective values of voltage U and current I, as well as the values of the phase angle of the load fn and the consumed active power P, are necessary for organizing the operation of the program control system. Their purpose is explained in the description of the principle of operation of the device.

The device operates as follows. Let in the initial mode of operation, after turning on the device into the supply network, the voltage level at the output terminals of the winding 3 of the supply transformer 1 is a certain value UQ. This voltage is the same and equal to the middle of the ranges of its regulation at the terminals of individual power receivers 4 and 5 of their group. Moreover, as part of the thyristor keys of blocks 18 and 19, thyristor keys with the same numbers, respectively, 18.2, 18.4, 18.6, 18.15, 18.16 (Fig. 2), etc., are included for the keys of block 19. And as part of the thyristor keys of blocks 20 and 21 included other thyristor

with С /, / / 1 keys with corresponding identical numbers. Thyristor transistor modules, which are connected in series in the circuit of the power receiver 4, are in the mode of operation with the conditional name Mode 9 (FIG. 3). The modules connected in series in the circuit of the power receiver 5 operate in the mode with the conditional name Mode 5 (Fig. 3). The initial voltage level at the input terminals of the power receiver 4 is equal to its maximum value, since the total maximum voltage level at the terminals of the primary windings 6 and 7 (Ue./max) of both modules is half the voltage control range at the terminals of the power receiver 4 and is in phase with the voltage UQ windings 3 of the supply transformer 1. At the input terminals of the power receiver 5, the initial voltage level is taken equal to its minimum value, since the total maximum voltage level at the primary terminals windings 8 and 9 (Us.gmax) of both modules is half the voltage control range at the terminals of the power receiver 5 and is in antiphase with the voltage UQ of the winding 3 of the supply transformer 1. The voltage control ranges at the terminals of the individual power consumers 4 and 5 are equal to Uo + Uejmax and Uo ± U8.9max- The latter can be the same or different, both in magnitude and in the temporal law of the change in voltage within the range of its regulation. The effective value of the voltage U at the terminals of individual power consumers 4 and 5 at any time is controlled by a software control system based on the data of the signals received by the processor unit 22.2 from

2SSC f.

12 functional blocks 23 and 24. At the command of the control unit 25

begins the process of regulating the voltage at the terminals of power consumers 4 and 5 according to the individual laws of its change in time specified for each power receiver. For this, the operator in the control unit 25 preliminarily puts in the form of tables information on the temporal laws of the voltage change at the terminals of individual group electrical receivers. In addition, tabular data about the permitted time points are placed at which a certain reconnection of the thyristor keys is possible during the natural switching of the latter. Periodically, this information from the control unit 25 is copied to the processor, namely, to its read-only memory - block 22.1. The processor unit 22.2 reads from the block 22.1 the necessary digital information about the points in time at which the connection schemes of the secondary windings 14, 15 and (or) 16, 17 of the transformer-thyristor modules should be changed. The latter are included in series in the circuit of the respective power consumers 4 and 5. The processor 22.2 processes this digital information, taking into account the current values of the phase angles of the load current fn of individual power consumers. The values of the phase angles are received in the processor unit 22.2 from the functional blocks 23 and 24. The processor unit 22.2 monitors the current time value and when it matches the allowed time points according to a certain algorithm (see Russian patent No. 21117575, class N 02 J 3/12, 3/18, N 02 M 5/257, 1998) removes pulses using the blocks of the output stages 26, 27 and (or) 28, 29

7.

13 controls with turn off thyristor keys of blocks 18, 19 and (or) 20,

21 old device operation modes. At the same time, it supplies control pulses to those thyristor switches that must be included in the new stationary operation mode of certain transformer-thyristor modules and the device as a whole. After the thyristor switch switching algorithm is implemented, the device appears in a new stationary mode of operation. This mode differs from the previous one in voltage level up or down at the terminals of one (or several) power consumers (s) of their group, or simultaneously at the terminals of all power consumers of the group by one (several) voltage regulation step (s). The value of one regulation step according to (see Russian patent No. 2119229, class N 02 M 5/12, G 05 F 1/253, 1998 - / prototype /) is 1/80 of the full regulation ranges of UolUe.ymax at the terminals of the power receiver 4 and Uo ± U89max at the terminals of the power receiver 5, respectively. As an example, we assume that in the new stationary mode, compared to the initial mode, there were changes in the composition of the included thyristor switches in blocks 19 and 21. The corresponding transistor-thyristor modules switched to operating modes with the conditional names Mode 8 and Mode 4, respectively (Fig. .3). The voltage at the terminals of the power receiver 4 decreased by one control step defined above, and at the terminals of the power receiver 5 it also increased by one step determined above.

 / .sG

14 Consider the options for the device when, under the conditions

technology, it is required to maintain at the terminals of individual power consumers changing over time, but in a very narrow range, the currents I or power R consumed by them. In this case, block 22.2 periodically polls function blocks about the current values of current I or power R consumed by certain power consumers. of a specific power receiver, the value of the controlled current or controlled power is in the specified range, then block 22.2 does not change the operating modes of those transformer-thyris torus modules that regulate the voltage at the terminals of this power receiver. Otherwise, when the current or power is greater (less) than the upper (lower) boundary of the allowed range of its change, the processor organizes the transfer of a certain transformer-thyristor module into a new stationary mode of operation. The new stationary mode provides at the terminals of this power receiver a decrease (increase) in voltage by one step of its regulation. This process continues until the controlled value is again in the specified range of its change.

The tests carried out confirm compliance with the Industrial applicability criterion. The device is in demand by enterprises.

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Claims (1)

A device for regulating voltage under load, containing a supply double-winding transformer, the primary winding of which is connected to the supply network, and between the output terminals of its secondary winding and the corresponding terminals of the electrical receivers, a circuit containing a series connection of "n" primary windings (where n = 1, 2, ...) transformers, respectively, "n" transistor-thyristor modules with thyristor key blocks and a functional block that includes a converter from the output of which to the system processor According to his command, the program control signals the magnitude of the phase angle of the load, the output terminals of the program control system are connected to the control electrodes of the thyristor keys of the transformer-thyristor modules through the output stage blocks, characterized in that when creating a circuit for simultaneously supplying a group of power receivers using circuits similar to the above, the terminals of the secondary winding of the supply double-winding transformer are connected to the corresponding terminals of each of the electrical receivers the joints, and the clamps and taps of the secondary windings of the transformers of all transistor-thyristor modules through thyristor switches are connected with the possibility of their switching among themselves, or counter-matching with respect to the corresponding primary windings of these transformers and connecting them in parallel to the output terminals of the secondary winding of the supply double-winding transformer, and the functional unit includes current and voltage sensors with the possibility of generating by the converter signals that carry information as a phase the load angle, and the values of voltage, current and active power, while the number of functional blocks is increased to the number of power receivers connected to the power supply circuit, and the number of output stages of the program control system is selected corresponding to the number of transistor-thyristor modules.