WO2007135209A1

WO2007135209A1 - Optimized static tap changer for high-tension/medium-tension (ht/mt) and medium-tension/low-tension (mt/lt) transformers

Info

Publication number: WO2007135209A1
Application number: PCT/ES2007/000287
Authority: WO
Inventors: Darío MONROY BERJILLOS; Antonio GÓMEZ EXPÓSITO
Original assignee: Universidad De Sevilla
Priority date: 2006-05-19
Filing date: 2007-05-17
Publication date: 2007-11-29
Also published as: ES2318961B1; ES2318961A1

Abstract

The present invention relates to a static tap changer for HT/MT and MT/LT distribution transformers based on switched thyristors, which achieves an increase in the number of output voltages of up to 50% for HT/MT transformers with linear adjustment and up to 100% for HT/MT transformers with coarse/fine regulation when the coarse winding is separated from the fine winding. In MT/LT transformers, there is an increase of 5 to 9 different output voltages using only 7 static switches, allowing, furthermore, passage from current manual regulation of output voltage to automatic or remotely controlled regulation.

Description

TITLE

Static tap changer optimized for high voltage / medium voltage (AT / MT) and medium voltage / low voltage (MT / BT) transformers

OBJECT OF THE INVENTION

The present invention relates to a static tap changer for AT / MT and MT / BT distribution transformers based on switched thyristors that achieves an increase in the number of output voltages of up to 50% for AT / MT transformers with linear regulation and up to 100% for AT / MT transformers with coarse / fine regulator when coarse and fine winding is separated. In MT / BT transformers the increase of 5 to 9 different output voltages is achieved using only 7 static switches, also allowing the passage of the current manual regulation of the output voltage to an automatic or remote control.

BACKGROUND OF THE INVENTION

The maintenance of the output voltage of the distribution transformers within the allowable or desired margins depending on the load circumstances is traditionally carried out by changing the transformer transformation ratio, so that the voltage ratio changes accordingly . To do this, the main windings are provided with a set of auxiliary windings that by connecting and disconnecting from the main winding, add or reduce turns, thus changing the relationship. The switching process is currently carried out in two basic ways: on load or without load. The switching in load is usual in the transformers AT / MT (High voltage / Medium voltage), whose service cannot be interrupted without seriously damaging the operation of the system. No-load switching is typical of MT / BT traffics in the Centers of Transformation, in which the load switching device is too bulky and expensive, so it is admitted that its service is interrupted while the switching is performed.

For charging switching, a very voluminous electromechanical regulator is used, with mobile elements, of slow operation and that requires expensive maintenance, being also a source of numerous failures throughout the life of the transformer due to the appearance of switching arcs.

The tap changers in caga generally respond to three basic schemes:

- Linear regulation, in which the regulation sockets are switched successively, adding or detracting a constant number of turns according to the tap changer commute in one direction or the other way around. - Regulation with positive-negative preselector, in which the regulation range is twice the tension of the regulation winding, connecting the main winding to one or the other end of the regulation winding and therefore, adding or subtracting the tension from it. Regulation with a coarse-fine preselector, which allows to include or eliminate a winding without regulation (coarse) sockets whose tension is equal to that of the winding with (fine) sockets, doubling its regulation range.

For switching without load, a tap changer under cover is currently used, which manually and after putting the transformer out of service previously, allows timely changes in the transformation ratio. In this case, the number of possible shots and voltages is very small.

These limitations are largely solved in the patent application P200500403, entitled "Socket changer for medium / low voltage transformers". In this application, a new approach to applying static switches based on switched thyristors is applied almost immediately to medium / low voltage transformers with the possibility of increasing the number of output voltages of the 5 usual values up to 9 different values without this meaning significant variation of the constructive arrangement of the current transformer, using 8 static switches.

DESCRIPTION OF THE FIGURES

Figure 1.-

Scheme of single phase coils of an AT / MT transformer with linear regulation. The phase consists of a main winding (P) and another regulation divided into groups of n turns between each of which there are accessible sockets (t). A mobile contact (c) can be moved automatically or remotely from one to another to add or detract groups of n turns to the main winding, thus changing the transformer transformation ratio and thereby the output voltage.

Figure 2.-

One-phase coil diagram of an AT / MT transformer with positive-negative preselector. The phase consists of a main winding (P) and another regulation divided into groups of n turns between each of which there are accessible sockets (t). The regulation winding is connected to the main one through a switch (cpn) to be able to preselect in this way the direction of the current by the regulation winding. A mobile contact (c) can be moved automatically or remotely from one outlet to another to add or detract groups of n turns that in turn will be added or subtracted from the main winding according to the direction of the current, thus changing the transformation ratio of the transformer and with it the output voltage.

Figure 3.- Scheme of single phase coils of an AT / MT transformer with a coarse-fine preselector. The phase consists of a main winding (P), a coarse regulation winding (B) in series with the main one, with accessible sockets (t) at its ends, and another of fine regulation divided into groups of n turns between each of which there are accessible shots (t). The regulation winding can be connected to the coarse or to the main one through a switch (cbf) to be able to preselect in this way if the coarse winding is intervened or not. A mobile contact (c) can be moved automatically or remotely from one outlet to another to add or detract groups of n turns that in turn will be added or subtracted from the already coarse main winding or only the main winding, thus changing the transformer transformation ratio and with it the output voltage.

Figure 4.-

This figure represents the way to connect the static switches based on power electronics (I) to the regulation sockets of the current AT / MT transformers. As indicated in the figure, only the sockets corresponding to groups of turns of the regulation winding in the sequences 1n, 3n, 3n, ..., 3n, 2n must be connected in the case of the number of groups of n turns multiple of 3 (Figure A); 1n, 1n, 3n, 3n, ..., 3n, 2n in the case of the number of groups of n turns multiple of 3 plus 1 (figure B) or 1n, 3n, 3n, ..., 3n, 2n , 2n in the case of being the number of groups of n turns multiple of 3 plus 2 (Figure C).

Figure 5.-

This figure represents the simplified structure of one of the windings of

Medium Voltage of a typical MT / BT distribution transformer. Each phase of the medium voltage winding is divided into main coils separated into two parts (3), (3 '), to each of which two auxiliary coils (4), (5), (6), (7) are connected ) through the junction points (8), (9), (10), (11), (12), (13). These terminals can in turn be connected or disconnected by means of a set of mechanical connections, (14).

Figure 6.-

In the figure a single phase of the medium voltage winding of an MT / BT transformer is shown equal to that represented in Figure 5 using 8 static switches based on switched thyristors (16), (17), (18), (19), (20), (21), (22), (23).

Figure 7.-

In the figure, a single phase of the medium voltage winding of an MT / BT transformer is shown equal to that shown in Figure 5 using 7 static switches based on switched thyristors (16), (17), (18), (19), (20), (21), (22).

Figure 8.-

The figure shows the single phase scheme of the high voltage winding of an ATYMT transformer with the structure corresponding to a linear regulation to which the electromechanical regulator has been replaced by static switches based on power electronics. The regulation winding is divided into groups of regulation coils with the sequence of turns 1n, 3n 3n, 2n, among which are the regulation sockets to which the static switches are connected. Said regulation winding is connected in series to the main winding, represented in the figure with the letter (P).

Figure 9.-

The figure shows the single-phase scheme of the high-voltage winding of an AT / MT transformer with the structure corresponding to a regulation with a coarse-fine preselector, to which the electromechanical regulator has been replaced by static switches based on electronics of power. The fine regulation winding is divided into groups of regulation coils with the sequence of turns 1n, 3n, ..., 3n, 2n, among which are the regulation sockets to which the static based switches are connected based in power electronics. Said fine regulation winding can be connected to the coarse winding (B) in three different ways: directly in series with it (Figure I), through two static switches that allow it to be added or bridged. (figure II), or through four static switches (figure Ul) that allow it to be polarized directly or inversely before connecting it or not to the main winding (P).

Figure 10.-

The figure shows the single-phase scheme of the high voltage winding of an AT / MT transformer with the structure corresponding to a linear regulation to which the electromechanical regulator has been replaced by static switches based on power electronics. The regulation winding is divided into 5 groups of regulation coils with the sequence of turns 1n, 3n, 3n, 3n, 2n, among which are the regulation sockets to which the static switches are connected (10a, 10b ,. .., 101). Said regulation winding is connected in series to the main winding, represented in the figure with the letter (P).

Figure 11.-

The figure shows the single phase scheme of the high voltage winding of an AT / MT transformer with the structure corresponding to a regulation with a coarse-fine preselector, to which the electromechanical regulator has been replaced by static switches based on electronics of power. The fine regulation winding is divided into 5 groups of regulation coils with the sequence of turns 1n, 3n, 3n, 3n, 2n, among which are the regulation sockets to which the static switches based on power electronics (11a, 11b, ..., 111).

Said fine regulation winding is connected to the coarse winding (B) through two static switches (11m, Hq) that allow adding or bridging it before connecting it to the main winding (P).

BRIEF DESCRIPTION OF THE INVENTION

The present invention consists of a static tap changer that allows versions applicable to both high reducing transformers medium voltage voltage (AT / MT transformers) as well as low voltage medium voltage reducing transformers (MT / BT transformers) based on power electronics with a new configuration of the elements that integrate it, so that in the case of AT / MT transformers, the direct replacement of the electromechanical tap-changer is achieved by an electronic one with minimization of the number of static switches used in the tap-changer and even the increase of the regulation range in the types of linear regulation and regulation with rough preselector. fine, and in the case of MT / BT transformers, 9 different output voltages are achieved using only 7 static switches, without this implying relevant changes in the structure and configuration of the transformers commonly used in current installations. This last case significantly improves the solution of 8 static switches proposed so far, since reducing the number of switches is an important factor in the practical application of! system both technically and economically.

DETAILED DESCRIPTION OF THE INVENTION

The invention consists of a new way of regrouping the regulating windings and the sockets that give access to them, replacing the changers of mechanical and electromechanical sockets with others based on static switches that allow in any case the regulation in charge and automated or remote control .

Each phase of a winding with regulation sockets can be represented as indicated in Figure 1. Between each two sockets there is a fixed number of turns n corresponding to a step of tensions. As the main contact goes through the shots, turns are added or subtracted in groups of n units to the main winding (P), thus performing

The regulation. In turn, if the direction of the current through the turns is changed, the voltage corresponding to each step may be subtracted instead of added, thus doubling the range of the regulation, as indicated in Figure 2. The current mechanical systems switch from one outlet to another through sequential mobile contacts that only allow slow ups or downs step by step and cause switching arcs that require permanent maintenance. The replacement of these mobile contacts by electronic power switches based on switched thyristors avoids these problems, allowing rapid jumps of any magnitude within the range of the regulator, without switching arcs. The present invention takes advantage of that ability of electronic switches to achieve additional advantages without implying changes in the regulation windings themselves.

Thus, by changing the direction of the current that polarizes the regulation coils in the reverse direction, it is possible to reduce the number of necessary sockets by grouping the auxiliary regulation windings, originally formed by k groups of n turns in series and intermediate sockets between each two of them, in sets of 1n turns, 2n turns or 3n turns connected in series in certain sequences. These groupings are optimal if they are performed in the following sequences:

. 1n, 2n, for 3 groups of n turns.

. 1n, 1n, 2n, for 4 groups of n turns.

. 1n, 2n, 2n, for 5 groups of n turns.

. 1n, 3n, 2n, for 6 groups of n turns.

. 1n, 1n, 3n, 2n, for 7 groups of n turns. . 1n, 3n, 2n, 2n, for 8 groups of n turns.

. 1n, 3n, 3n, 2n, for 9 groups of n turns

That is, each phase of the regulation winding will always have an initial group of 1n turns and a final group of 2n turns. If the number k of groups of n turns is a multiple of 3, the remaining turns will be grouped into (k-3) / 3 groups of 3 turns. If the number k of groups of n turns turns in a unit to a multiple of 3, a second group of 1 turns will be placed and the remaining ones will be grouped into (k-4) / 3 groups of 3 turns. If the number k of groups of n turns turns in two units to a multiple of 3, a penultimate group of 2 turns will be placed before the last one, and the rest will be grouped in (k-5) / 3 groups of 3 turns.

Therefore, the groupings must be made in the sequence 1n, 3n, 3n ,, .., 3n, 2n, in the case of a number of groups of n turns multiple of 3, or 1n, 1n, 3n, .. ., 3n, 2n; and 1n, 3n, ..., 3n, 2n, 2n for intermediate cases between said multiples.

The schemes corresponding to each of the groupings are indicated in the three graphs of Figure 4. In them it can be observed that, as the static switches are opened or closed, it can be possible to add or detract coils in groups of n turns, within a range that goes from zero to the total sum of turns of the regulation winding, in regular steps. In addition, for each output voltage value, only two of the switches have to be closed, all others being open, which implies that there will only be two switches in series simultaneously in each case. It can also be seen that two shots are made unnecessary for each group of 3 turns and one shot for each group of 2 turns. The invention can be divided into two basic systems, as applicable to AT / MT transformers or MT / BT transformers.

MT / BT transformers

The present invention replaces the static switch model of 8-circuit sockets with another that performs the same function but using only 7 switches, without regrouping the auxiliary windings differently, as indicated below:

The usual simplified configuration of an MT / BT distribution transformer is indicated in Figure 5. It shows one of the three phases of the MT winding that is composed of a main coil divided into two parts (3) and (3 ' ), each of NP / 2 turns, to each of which two auxiliary coils (4), (5), (6), (7), each of N turns are connected. The junction points (8), (9), (10), (11), (12), (13), are accessible by means of welded terminals (sockets). In the current configuration said terminals can in turn be connected or disconnected by means of a set of mechanical connections, (14), which are manually operated through a mechanism whose control is located in the lid of the transformer tank, and which respond to the connection diagram of the figure. In this way, by closing and opening the connections, the auxiliary coils are added to the main coils, changing the transformation ratio and with it! To the output voltage of the transformer, achieving 5 different output voltages for the same input voltage, or the same output voltage for 5 different values of the input voltage. In Figure 6 8 switches (16), (17), ..., (23) are used and 9 different transformation ratios are achieved and with that 9 different output voltages without changing the structure or the number of existing coils currently in MT / BT transformers. If it becomes necessary to separate the auxiliary coils from the main ones to adopt the configuration of the scheme, which can be done with a minimum intervention in the existing transformers or immediately in the subsequent ones. The increase in the number of voltages is achieved because the assembly allows the circulation of current both in one direction and the opposite in each auxiliary coil, depending on which switches are open or closed, so that the generated flows can be added or subtracted, this last possibility being the one that allows the increase of obtainable voltage values, as indicated in the following table:

In this way, the generated flow will be added or subtracted from the main one according to the connection, while in the current assemblies it is only added, thus being able to add four more values to the 5 of the assembly of Figure 5 without significant changes in the usual structure of the transformers currently in use, as indicated in the previous table.

However, the present invention proposes an even more economical configuration that also achieves 9 different transformation ratios and with that 9 output voltages, but using only 7 switches instead of 8, with a simple variation of the scheme, as observed in Ia Figure 7, and in the data of the following table:

As can be seen from the table and Figure 7, by simultaneously activating two of the switches it is achieved that the current can take up to nine possible paths through the medium voltage winding; a first route that avoids auxiliary windings, closing switches (16) and (17), four different paths that cross auxiliary windings in a "positive" direction, closing each time the pairs of switches ((16), (19) ), ((16), (20)), ((18), (22)), ((16), (22)), and four routes through auxiliary windings in a "negative" direction, closing each time the pairs of switches ((17), (21)), ((19), (21)), ((20), (21)), ((17), (18)), generating nine possible voltage levels at the output of) transformer.

This last case significantly improves the solution of 8 static switches proposed so far, both in technical and economic viability, since the number of static switches is decisive, both for its cost, and for the space they occupy in the transformer and the need for control and cooling of the power electronics elements used. - AT / MT transformers with linear regulation

This type of charge regulation uses a load tap switch which is adding or removing packages of n turns, to regulate the output voltage in equal steps, as indicated in Figure 1. Figure 8 shows a configuration proposed in this patent. The main winding is indicated with the letter P, and the grouping of sockets and arrangement of the static switches of the regulation winding proposed by the present invention can be observed in order to optimally achieve the voltage regulation with an extension twice the regulation range , by allowing the polarization of the coils in both directions, analogously to the method indicated in the application to the MTYBT transformers. In addition, the number of shots required in the regulation winding is significantly reduced.

A T / MT transformers with coarse / fine preselector. In this type of regulation, represented in Figure 3, the winding with sockets is connected to the main one through a switch that allows to add or not add a second auxiliary winding (coarse winding, indicated with the letter B) with only two shots and with a number of turns equal to the total winding with shots. Figure 9 (I) shows the configuration proposed in this patent capable of performing the same functions as indicated in Figure 3, without making changes in the original structure of the windings, with a decrease in the number of shots and elimination of! preselector (cbf). Figure 9 (II) indicates the proposal in this invention that allows 50% more voltage steps to be added, by allowing the polarization of the winding to be reversed with sockets, grouping these according to the optimal arrangement already indicated. In addition, the number of necessary shots is significantly reduced without changing the structure of the windings, as in the previous case. Also, if it were possible to separate the coarse winding from the main one, the steps could be increased up to 100%, using two more switches that also allow the coarse winding to be reversed polarized, as indicated in Figure 9 (III). - A T / MT transformer with positive-negative preselector.

In this case, the winding with sockets is connected to the main one by means of a switch so that the current can polarize the auxiliary windings in both directions, so that the voltage of each step can add or subtract from that of the main winding, as indicated in figure 2. Figure 8 indicates the configuration proposed in this patent for this type of regulator, in which the number of regulation sockets is also reduced and eliminated the switch corresponding to the positive-negative preselector (cpn).

EMBODIMENT OF THE INVENTION

MT / BT transformers.- From the scheme indicated in Figure 7 corresponding to a phase of! medium voltage winding of an MT / BT transformer, and considering a typical voltage ratio of 20,000 / 400 V under nominal conditions, the different output voltage values that can be obtained according to the state of the switches are shown, assuming a power supply fixed at 20,000 V.

As can be seen, the regulation of the output voltage It is much wider, allowing to adapt to a greater range of variations in the input voltage or voltage drops, and also do it automatically without interruption of supply.

- AT / MT transformers with linear regulation or with positive-negative preselector. -

If we consider the scheme of Figure 8 and it is applied to a 66/20 kV transformer, whose regulation winding has 12 steps of n turns, as indicated in Figure 10, each of which corresponds to 1% of the rated voltage, output values from 17600 V to 22400 V could be obtained, in 200V steps, similar to that indicated in the previous example of the MT / BT transformer.

Thus, to achieve the nominal voltage ratio, it is sufficient to close the switches 9a and 9b, keeping the others open. To add 7n turns the switches 9a and 9h must be closed. To detract 5n turns (add 5n turns polarized inversely) the switches 9k and 9h must be closed. Similarly, all other values must be followed:

- AT / MT transformer with coarse fine preselector. -

If the scheme of Figure 9 (II) is considered and applied to a 66/20 kV transformer, whose "fine" regulation winding has 12 steps of n turns, as indicated in Figure 11, each of which corresponds to 1% of the nominal voltage Un, and a "coarse" regulation winding, indicated in the figure with the letter B, of 12n turns, output values could be obtained from 15200 V to 22400 V in 200V steps, similar to that indicated in the previous example of the MT / BT transformer.

Thus, to achieve the nominal voltage ratio, it will be sufficient to close the switches 11a, 11b and 11 m, keeping the others open. To add 7n turns the switches 11a, 11h and 11m must be closed. To detract 5n turns (add 5n turns polarized inversely) the switches 11k, 11h and 11m must be closed. To detract 15n turns, for example, switches 11e, 11d and 11q must be closed. Similarly, all other values must be followed:

Proceeding in the manner indicated in the table, the range of stresses indicated in the example can be achieved. Similarly, the other two possible configurations applicable to transformers with coarse-fine presets indicated in Figure 9 (1) and 9 (III) would proceed.

Claims

R E I V I N D I C A C I O N E S

1 ^a. - Changer device for medium / low voltage transformers, of the type used in the supply of low voltage lines to allow regulating the voltage levels at the output of said transformer depending on the load of the line of distribution associated with it, each one of its three medium voltage windings corresponding to each phase being constituted, by a main winding divided into two equal parts (3), (3 ^J ) and by a series of auxiliary windings (4), (5), (6) and (7) that can be connected and disconnected from their main winding to vary said voltage ratio, characterized by incorporating, associated to the sockets of said auxiliary windings, seven static electronic switches based on power electronics ( 16), (17), (18), (19), (20), (21) and (22), which can be automatically regulated or remote controlled.

2 .- Device tap changer transformer medium / low voltage, according to claim 1 wherein six of seven electronic switches (16), (17), (18), (19), (21) and (22 ) are distributed so that three of them (16), (18) and (21) each connect a half of the main winding (3) with an intermediate socket of the auxiliary windings (8), (9) and (13) , and each of the other three (17), (19) and (22) connect one of said sockets with the other half of the main winding (3 '); The seventh switch (20) is connected between the intermediate socket (10-11) and the second half of the main winding (3 '), in such a way that by means of the simultaneous operation of two of said switches, nine possible paths of the Ia are achieved. current through the medium voltage winding; a first route that avoids auxiliary windings, four different paths that cross auxiliary windings in a "positive" direction and four paths that cross auxiliary windings in a "negative" direction, generating nine possible voltage levels at the output of the transformer. 3 ^a. - Changer device for high / medium voltage transformers, whose regulation winding is formed by a number k of auxiliary coils multiple of three, capable of replacing the electromechanical regulator without the need to alter the configuration of the transformer windings , minimizing the number of static switches and regulating sockets used, and characterized by using electronic switches distributed two to two over the sockets, grouping the auxiliary coils, each of n turns, in a first group of n turns, in series with (k-3) / 3 groups of 3n turns and in series with a last group of 2n turns, using only the existing regulation sockets between each of these groups, to which the static switches are connected.

4 .- Device tap changer transformer high / medium voltage, the regulating winding is formed by a k number of coils auxiliary multiple of three plus one, able to replace the electromechanical regulator without altering the configuration of the windings of the transformer, minimizing the number of static switches and regulation sockets used, and characterized by using electronic switches distributed two to two over the sockets, grouping the auxiliary coils, each of n turns, into two initial groups of n turns , in series with (k-4) / 3 groups of 3n turns and in series with a last group of 2n turns, using only the existing regulation sockets between each of these groups, to which the static switches are connected. 5 ^a. - Changer device for high / medium voltage power transformers whose regulation winding is formed by a number k of auxiliary coils multiple of three plus two, capable of replacing the electromechanical regulator without the need to alter the configuration of the transformer windings, minimizing the number of static switches and regulation sockets used, and characterized by using electronic switches distributed two to two over the sockets, grouping the auxiliary coils, each of n turns, into an initial group of n turns, in series with (k-5) / 3 groups of 3n turns and in series with two last groups of 2 turns, using only the existing regulation sockets between each of these groups, to which the static switches are connected

6 ^a. - Changer device for high / medium voltage transformers according to claims 3 to 5, characterized in that the simultaneous activation, automatically or remotely, of two of the switches achieves 2k + 1 different paths of the current through the regulation winding, generating 2k + 1 values of different and equidistant voltage relations. 7. ^A tap changer device for high / medium voltage transformers that replaces the electromechanical tap changer of the transformers equipped with a linear regulator with another that uses static switches based on power electronics according to any of the configurations described in claims 3 , 4, 5 and 6, characterized by its ability to double the number of voltage levels of the regulator without altering the regulation winding or the main winding (P), by allowing the circulation of the current in both directions.

8 .- Device tap changer transformer high / medium voltage changer replacing electromechanical jacks gifted transformers regulator positive- negative preselector switches employing another static based on power electronics, according to one of the configurations described in claims 3, 4, 5 and 6, characterized in that it does not alter the regulation winding or the main winding (P), eliminating the need for the preselector.

9 .- Device tap changer transformer high / medium voltage replacing changer electromechanical jacks gifted transformers regulator preselector coarse-fine other employing switches static based on power electronics, according to any of the configurations described in claims 3, 4, 5 and 6 for the fine regulation winding, characterized in that it does not alter its original structure or that of the main winding (P), does not perform regulation on the coarse winding (B), eliminating Ia need for the preselector (I) and allowing the same number of different voltages as the electromechanical regulator it replaces

10 .- Device tap changer transformer high / medium voltage replacing changer electromechanical jacks gifted transformers regulator preselector coarse-fine other employing switches static based on power electronics, according to one of configurations described in claims 3, 4, 5 and 6 for the fine regulation winding, characterized in that it does not alter its original structure or that of the main winding (P), allowing the circulation or not of circulation of two

The current through the coarse winding (B), increasing the number of different possible output voltages by 50% with respect to the electromechanical regulator it replaces, eliminating the need for the preselector.

11 .- Device tap changer transformer high / medium voltage replacing changer electromechanical jacks gifted transformers regulator preselector coarse-fine other employing switches static based on power electronics according to any of the configurations described in claims 3, 4, 5 and 6 for the fine regulation winding, characterized in that without altering its original structure or that of the main winding (P) and by using 4 static switches and the physical separation of the coarse winding B of the winding main P allows the circulation of the current through the coarse winding in both directions, increasing the number of different possible output voltages by 100% with respect to the electromechanical regulator it replaces, eliminating the need for the preselector.