SU1713014A1 - Method of automatic transformer-voltage regulation - Google Patents

Abstract

The invention relates to electrical engineering. 8 in particular to the regulation of the voltage of consumers fed from different power lines. The purpose of the invention is to improve the quality of voltage regulation, because the voltage of the transformer is reduced in the downward direction not only in cases where the voltage values at the two controlled points are less than the lower limits of the dead zones, but also in those cases when in one of the controlled points the voltage value is less than the lower -. in the second controlled point, the voltage is less than the upper limit of the dead zone by more than one level of transformer control. 1 il.

Description

The invention relates to electrical engineering, in particular to regulating the voltage of consumers powered from different power lines.

The purpose of the invention is to improve the quality of voltage regulation.

The drawing shows a block diagram of a device that implements the proposed method.

The device contains a transformer 1 with an automatic voltage control device under load, outgoing power lines 2 and 3, a voltage transformer 4, current transformers 5 and 6, current sensors 7 and 8, which convert current values in lines 2 and 3 into values proportional to the voltage drop from the low voltage tires of transformer 1 to the corresponding controlled

points with a constant voltage, blocks 9. 10 stress isolation at controlled points of lines 2 and 3. difference difference units 11j 12, AND 13.14 logic units 15 and 16 comparison units. Logic elements OR 17.18, elements 19. 20 time-exposures and executive bodies 21,22.

The device that implements the method works as follows.

Blocks 9 and 10 isolate the difference between the voltage on the busbars of transformer 1 and the voltage drop to controlled points. Essentially, from the outputs of blocks 9 and 10, the actual voltages at controlled points are removed depending on the outflow of load in lines 2 and 3. The voltages from the outputs of blocks 9 and 10 are fed to the inputs of blocks 11 and .12. These blocks isolate differences when comparing actual values.

voltages at the controlled points of power lines 2 and 3 with the voltage of the upper limits of the dead zones of the voltage regulator. If these differences exceed the voltage control level of transformer 1, the output signals of blocks 11 and 12 appear. The signal from block 11 is fed to the first input of element 13 and the signal from block 12 to the second input of element 14.

At the same time, the voltages from blocks 9 and 10 are fed to the inputs of blocks 15 and 16 of the comparison. These blocks compare actual voltages at controlled points with the upper and lower limits of the dead zones. In this case, if the actual voltages at the controlled points exceed the upper limits of the dead zones, signals appear at the first outputs of blocks 15, 16. If the voltages are below the lower limits of the dead zones, then signals appear at the second outputs of these blocks.

Suppose, for example, that at a given voltage on the buses of transformer 1 at a controlled point on line 2, the voltage goes beyond the upper limit of the deadband. This phenomenon can be caused by a decrease in the voltage drop to a controlled point due to a decrease in the load current. The reduced value of the voltage drop from the current sensor 7 will go to the voltage isolation unit 9 at the controlled point. Since the actual voltage at the controlled point has increased and exceeded the upper limit of the dead zone, a signal appears at the first output of the comparison unit 15. Further, the signal from the OR element 17 after the set time (1-2 minutes) from the time delay element 19 will turn on the executive unit 21, which will reduce the voltage of the transformer 1 by one control step. If, at the same time, the actual voltage at the controlled point enters the dead zone, the further reduction of the voltage by the executive body 21 will cease.

In the case of an increase in the load current in pini 3, an increased value of the voltage drop is output from the output of the current sensor 8.

The voltage at the output of the voltage allocation unit 10 at the controlled point will decrease. Its value in block 16 is compared to the boundaries of the dead zone. Let us consider, for example, that the voltage at the output of block 10 goes beyond the lower limit. Taking this into account, a signal appears at the second input of the element And 13 from the second output of block 16

(according to Wits, of course, the signal from block 12 at the second input of the And 14 element).

To further implement the method, it is necessary to follow the actual

voltage at the controlled point of line 2. This voltage is separated by block 9, which is fed to the input of difference difference unit 11 and to the input of comparison unit 15.

Suppose that the actual voltage at the controlled point became less than the calculated one, but did not exceed the lower limit of the dead zone. In this case, the signal from the second output of the block 15 is not

will be.

If the difference between the actual voltage at the controlled point of line 2 and the upper limit of the dead zone is greater than the step

transformer voltage control, the signal from block 11 will go to the first input of the element And 13. There will be a coincidence of the signals only on the element And 13, The element OR 18 will work and through the element

The 20 time delay will switch on the executive unit 22, which will add the voltage of the transformer 1 by one step. If the signals from the block 11 or from the block 16 disappear in this case, the further increase in voltage will stop.

Based on the description of the method, it is clear that a voltage reduction signal appears in cases as in the known technical solutions.

As regards the voltage boosting signal, the proposed method appears in two cases. The first of these corresponds to a decrease in stresses when they become less than the lower limits.

dead zones at the controlled points of both lines. In another case, a voltage boost signal is issued when in one of the lines the voltage at the controlled point has become less than the lower

deadband boundary.

In this case, the voltage at the controlled point of the second line may be in the dead zone. The difference of this voltage in comparison with the upper limit

deadband must exceed the transformer voltage control level.

The positive effect of using this technical solution is

in improving the quality of voltage regulation in electrical networks.

Claims (1)

Claims The method of automatic voltage regulation of a transformer, which consists in measuring the voltage at at least two points of the distribution network, corrects their value according to the laws of counter-regulation depending on the load currents at the controlled points, compare the values obtained with those given dead zones and if at both controlled points the values of the received voltages are less than the lower limits of the dead zones, then the transformer voltage increases, and If hot least one of the monitored points of the value obtained voltage exceeds the upper boundary of the dead zone, the derivative T drop voltage transformer, characterized in that, in order to increase quality control voltage if one of the monitored points obtained value the voltage is less than the lower limit of the dead zone, and at the second controlled point the value of the voltage received is in the dead zone, then the Hob times between the upper limit of the second point dead zone and its values are measured and if the result of this comparison exceeds the transformer voltage control level ; This increases the voltage of the transformer.