WO2017181960A1

WO2017181960A1 - Lightning protection on-load regulated-capacity transformer, and on-load regulated-capacity switch

Info

Publication number: WO2017181960A1
Application number: PCT/CN2017/081185
Authority: WO
Inventors: 吴正文; 姜方军
Original assignee: 浙江宝威电气有限公司
Priority date: 2016-04-20
Filing date: 2017-04-20
Publication date: 2017-10-26
Also published as: CN105788834B; CN109637793A; CN105788834A; CN109637793B

Abstract

A lightning protection on-load regulated-capacity transformer, and an on-load regulated-capacity switch. The on-load regulated-capacity transformer comprises a low-voltage winding, a high-voltage winding, and an on-load regulated-capacity switch. When the on-load regulated-capacity switch switches the regulated-capacity transformer to a large-capacity state, the transformer winding uses a Dyn11 connection mode, and when the on-load regulated-capacity switch switches the regulated-capacity transformer to a small-capacity state, the transformer winding uses a Yzn11 connection mode. When switching to the small-capacity is implemented, the Yzn11 connection is implemented, and a strong capacity for bearing unbalanced load is provided, that is, a strong single-phase power supply capability is provided, which is applicable to a region where a three-phase load cannot be easily balanced. In addition, a good lightning protection feature is provided, which is specially applicable to a region where the on-load regulated-capacity transformer is suitable for serving as a lightning protection transformer in a region where thunders frequently happen or a region where the electrical resistivity of soil is high.

Description

Lightning type load-carrying transformer and on-load capacity adjustment switch

Technical field

The invention belongs to the technical field of transformer equipment in the power industry, and in particular relates to a lightning protection type load-carrying transformer and an on-load capacity adjustment switch.

Background technique

The load-carrying transformer is a kind of transformer with two sizes of rated capacity. According to the load, the corresponding adjustable capacity switch is used to switch the connection mode of the transformer winding without cutting off the power supply, and then the transformer is realized in two different capacities. Switch between.

At present, the lightning protection measures for load-carrying transformers on the market are mainly realized by external lightning protection devices. The device for destroying lightning by destroying its own structure has high cost and poor lightning protection effect; The structure of some adjustable switches also limits the lightning protection effect of the load-carrying transformer.

In Chinese patent CN105321744, a transformer on-load capacity adjustment switch is disclosed, which adopts a vacuum interrupter to form a high-voltage coil switching system and a low-voltage coil switching system, which effectively solves the arc-extinguishing problem on the high-voltage side and the low-voltage side, and is maintenance-free. , long life and other advantages.

During the working process, the permanent magnet mechanism operates once, and the low-pressure transition vacuum interrupter needs to complete the opening-closing-opening action, and before it performs the action from closing to opening, it needs Waiting for the low-voltage first parallel vacuum interrupter and the low-voltage second parallel vacuum interrupter to effectively extinguish the arc can be carried out; and because the permanent magnet mechanism acts once very short, it is prone to uneffective arc extinguishing, low pressure The transitional vacuum interrupter has already started the opening action, which will cause the transformer to burn out.

Summary of the invention

In view of the above problems, the present invention provides a lightning protection type load-carrying transformer and an on-load capacity adjustment switch which have good lightning protection effect and are resistant to three-phase unbalance.

In order to achieve the above object, the present invention adopts the following technical solutions: a lightning protection type load-carrying transformer, including a low-voltage winding, a high-voltage winding, and an on-load capacity-adjusting switch for switching a transformer between large and small capacities. When the load-carrying switch is switched to the large-capacity state, the winding adopts the Dyn11 coupling mode; when the on-load capacity-adjusting switch switches the volume-adjusting transformer to a small capacity, the winding adopts the Yzn11 coupling mode.

Further, the load-carrying switch includes a high-voltage switching system and a low-voltage switching system, and each phase of the low-voltage switching system includes a first parallel vacuum interrupter, a second parallel vacuum interrupter, and a third parallel vacuum interrupter. Room, series vacuum interrupter and low pressure transition vacuum interrupter. By setting three parallel vacuum interrupters, a series vacuum interrupter and a transitional vacuum interrupter, each vacuum interrupter needs only one action during the conversion process; and the whole process is only After the low-pressure transitional vacuum interrupter is opened, it needs to be extinguished, which can give enough time for the low-pressure transitional vacuum interrupter to extinguish the arc, which effectively ensures the effective arc extinguishing during the volume adjustment process; the overall structure is simple and the design is ingenious. The failure rate is low and suitable for promotion.

Further, the low-voltage transitional vacuum interrupter has a transition resistor connected in parallel.

Further, the low-voltage transitional vacuum interrupter has a transition resistor connected in series.

Further, when the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third parallel vacuum interrupter are in a closed state, the series vacuum interrupter and the low pressure transition vacuum interrupter are When the state is opened, the two sets of coils in each phase of the low voltage winding of the transformer are connected in parallel; when the series vacuum interrupter is in the closed state, at the same time When a parallel vacuum interrupter, a second parallel vacuum interrupter, a third parallel vacuum interrupter, and a low-voltage transitional vacuum interrupter are in an open state, a set of coils of one phase of the low voltage winding of the transformer and another The set of coils of the phase presents an inverse series connection. According to such action sequence, not only can the low-voltage winding realize reliable and convenient conversion between the yn junction and the zn junction, but also can effectively extinguish the arc during the conversion process, and the arc extinguishing time can meet the highest national standard, and the use is safe and reliable.

Preferably, each of the vacuum interrupters operates in the following sequence:

First, the low-pressure transition vacuum interrupter is opened;

Then, the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third parallel vacuum interrupter are all closed;

Finally, the series vacuum interrupter is opened, so that the low voltage winding of the transformer completes the conversion from zn junction to yn junction.

The invention also discloses an on-loading capacity-adjusting switch having a first state and a second state, comprising a high-voltage switching system and a low-voltage switching system, wherein when the volume-adjusting switch is in the first state, the transformer winding is in a Dyn11 coupling mode; When the volume adjustment switch is in the second state, the transformer winding is in a Yzn11 coupling mode.

Further, each phase of the low-voltage switching system includes a first parallel vacuum interrupter, a second parallel vacuum interrupter, a third parallel vacuum interrupter, a series vacuum interrupter, and a transition vacuum with a transition resistor connected in series Arc chamber.

Advantageously, each phase of the low-voltage switching system includes a first parallel vacuum interrupter, a second parallel vacuum interrupter, a third parallel vacuum interrupter, a series vacuum interrupter, and a transitional vacuum with parallel transition resistance Arc chamber.

Further, when the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third parallel vacuum interrupter are in a closed state, the series vacuum interrupter and the low pressure transition vacuum interrupter are In the state of opening, the two sets of coils in each phase of the low voltage winding of the transformer are connected in parallel; when the series vacuum interrupter is in the closed state, the first parallel vacuum interrupter and the second parallel vacuum interrupter When the third parallel vacuum interrupter and the low-voltage transition vacuum interrupter are in the open state, the set of coils of one phase of the low voltage winding of the transformer and the set of coils of the other phase are connected in reverse series.

Preferably, each of the vacuum interrupters operates in the following sequence:

First, the low-pressure transition vacuum interrupter is closed;

Then, the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third parallel vacuum interrupter are all opened;

Then closing the series vacuum interrupter;

Finally, the low-voltage transition vacuum arc-extinguishing is opened, so that the low-voltage winding of the transformer completes the conversion from the yn junction to the zn junction.

Each of the vacuum interrupters operates in accordance with the following sequence:

First, the low-pressure transition vacuum interrupter is opened;

Finally, the series vacuum interrupter is opened, so that the transformer low voltage winding completes the conversion from yn junction to zn junction.

In summary, the beneficial effects of the present invention are: the load-carrying transformer of the present invention adopts the Yzn11 coupling mode when adjusting to a small capacity state, which not only has a strong bearing capacity. Unbalanced load capability and good lightning protection characteristics; the load-carrying switch of the present invention is connected to the circuit by parallel or series connection of the low-voltage transitional vacuum interrupter and the transition resistor, thereby ensuring the process of adjusting the volume. The realization of continuous electric operation, and the use of a reasonable number of vacuum interrupters, effectively ensure a reasonable arc extinguishing time and reliable arc extinguishing effect; the overall structure is simple, economical and energy efficient, suitable for promotion.

DRAWINGS

1 is a circuit diagram of a high voltage side winding of the present invention in a small capacity.

2 is a circuit diagram of the high voltage side winding of the present invention at a large capacity.

Fig. 3 is a schematic view showing another circuit of the high voltage side winding of the present invention in a small capacity.

Fig. 4 is a schematic view showing another circuit of the high voltage side winding when the present invention is in a large capacity.

Fig. 5 is a circuit diagram showing the low-voltage side winding of the present invention in a small capacity.

Fig. 6 is a circuit diagram 1 of the low voltage side winding in the capacity conversion process of the present invention.

Fig. 7 is a second schematic diagram of the circuit of the low-voltage side winding in the capacity conversion process of the present invention.

Fig. 8 is a circuit diagram showing the low-voltage side winding of the present invention at a large capacity.

Fig. 9 is a schematic view showing another circuit of the low-voltage side winding of the present invention in a small capacity.

Fig. 10 is a schematic view showing another circuit of the low-voltage side winding of the present invention at a large capacity.

Figure 11 is a schematic diagram of still another circuit of the low voltage side winding of the present invention in a small capacity.

Figure 12 is a schematic diagram of still another circuit of the low voltage side winding of the present invention at a large capacity.

Figure 13 is a timing chart showing the operation of each of the vacuum interrupters in the low-voltage side winding of the load-carrying switch of the present invention.

Wherein, K represents a vacuum interrupter, the symbol "day" indicates that the vacuum interrupter is in the closed state, the symbol "head" indicates that the vacuum interrupter is in the open state; R represents the transition resistance; T represents time.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention.

A lightning protection type load-carrying transformer, comprising a three-phase high-voltage winding, a three-phase low-voltage winding, an on-load capacity-adjusting switch and other metal and non-metal structural members constituting the transformer, and the on-load capacity-adjusting switch is switched to a transformer When in a large capacity state, the winding adopts a Dyn11 coupling mode; when the on-load capacity modulation switch switches the modulating transformer to a small capacity, the winding adopts a Yzn11 coupling manner.

Specifically, the low-voltage winding of each phase includes two coils of equal number of turns, and the two coils are wound on the iron core by axially symmetric distribution. Of course, in other embodiments, the two-stage coil orientation may also be The distribution is wound on the iron core, or the two coils are wound side by side in parallel on the iron core, or the two coils are wound and overlapped;

In this embodiment, each phase of the low-voltage winding includes two coils, or a first coil group and a second coil group formed by combining a plurality of coils, and the two coil groups have the same number of turns and are axially symmetrically distributed. Winding on the core can also achieve the same technical effect.

The load-carrying transformer provided in this embodiment realizes the Yzn11 coupling mode when switching to a small capacity, and has a strong ability to withstand unbalanced load, that is, has a strong single-phase power supply capability, which is for three Where the phase load is difficult to balance (such as rural and mountainous areas), it is particularly suitable; and it has good lightning protection characteristics, and is especially suitable for lightning protection transformers in areas with multiple mines or areas with high soil resistivity.

The embodiment further provides an on-load capacity-adjusting switch, which is applied to the above-mentioned lightning protection function, the load-carrying switch has a first state and a second state, and the volume-adjusting switch is in the first state. The winding of the transformer is in the Dyn11 coupling mode; when the volume modulation switch is in the second state, the winding of the transformer is in the Yzn11 coupling mode.

Specifically, the load-carrying switch includes a high-voltage coil switching system, a low-voltage coil switching system, and a driving mechanism. Taking one phase as an example, in each phase, as shown in FIG. 1 and FIG. 2, the high-voltage coil switching system includes The corner is connected to the vacuum interrupter K2, the star is connected to the vacuum interrupter K1, and the high-voltage transitional vacuum interrupter Kg is connected with the transition resistor R. The corner-connected vacuum interrupter K2 causes the high-voltage coil to be triangularly connected when the switch is closed. The star-connected vacuum interrupter K1 causes the high-voltage coil to be star-connected when the switch is closed; specifically, in the embodiment, the high-pressure transitional vacuum interrupter is connected in series with the corner-connected vacuum interrupter; In an embodiment, the high-pressure transitional vacuum interrupter may also be connected in series with the star-connected vacuum interrupter, or as shown in FIGS. 3 and 4, respectively, in the corner-connected vacuum interrupter K2 and the star-connected vacuum interrupter K1. A high-pressure transitional vacuum interrupter Kg, and the high-voltage transitional vacuum interrupter is connected in parallel with a transition resistor R.

Specifically, taking one phase as an example, as shown in FIG. 5-8, the low-voltage switching system of each phase includes a first parallel vacuum interrupter Kb1, a second parallel vacuum interrupter Kb2, and a third parallel vacuum interrupter. a chamber Kb3, a series vacuum interrupter Kc, and a low-voltage transitional vacuum interrupter Kg connected with a transition resistor R; of course, in other embodiments, the transition resistor R may be connected in series with the low-voltage transitional vacuum interrupter Kg Connecting, a transition resistor R is connected in series to the low-voltage transitional vacuum interrupter Kg to form a transition branch, which may be connected in parallel with the second The two ends of the vacuum interrupter Kb2 are shown in FIG. 9 and FIG. 10; alternatively, the transition branch may be paralleled at both ends of the third parallel vacuum interrupter Kb3, as shown in FIGS. Among them, when shown in Figures 9 and 11, when the volume modulation transformer is in a small capacity state, the circuit diagram of each vacuum interrupter and the low voltage coil; when shown in Figs. 10 and 12, when the capacity transformer is in a large capacity state, each Schematic diagram of the vacuum interrupter and the low voltage coil.

The driving mechanism comprises a set of permanent magnet mechanism and a transmission device matched with the permanent magnet mechanism, and all the vacuum interrupter actions are reciprocally driven by the transmission device, so that the vacuum interrupters are opened according to the designed timing. Closing action, thereby changing the connection mode of each coil in the transformer winding, so as to achieve the purpose of adjusting the capacity of the transformer;

Specifically, as shown in FIG. 5-8, the first-stage coil La1 and the second-stage coil La2 of the a-phase have the same number of turns, and the front end of the first-stage coil La1 and the first parallel vacuum interrupter Kb1 are respectively The vacuum interrupter Kc is connected in series, the rear end of the first coil La1 is connected to the second parallel vacuum interrupter Kb2, and the rear end of the second coil La2 is connected to the third parallel vacuum interrupter Kb3. ;

For convenience of description, the first segment coil La1 and the second parallel vacuum interrupter Kb2 in FIG. 5 are denoted as a node m, and the second segment coil La2 and the second parallel vacuum interrupter Kb2 are denoted as a node n. Connect the node m of the a-phase to the node n of the c-phase through the wire 1, connect the node m of the b-phase to the node n of the a-phase through the wire 2, and connect the node m of the c-phase to the node of the b-phase through the wire 3 n;

Therefore, when the strain transformer is in a small capacity state, the low voltage winding is shown in Figure 5, and the high voltage winding is shown in Figure 1:

In the small capacity state, the series vacuum interrupter Kc in each phase of the low voltage winding is in combination The state of the gate, at the same time, the first parallel vacuum interrupter Kb1, the second parallel vacuum interrupter Kb2, the third parallel vacuum interrupter Kb3 and the low-voltage transitional vacuum interrupter Kg are in a state of opening, at which time some of the transformer low-voltage windings One segment of one phase coil and one segment of another phase coil are connected in reverse series; specifically, the second segment coil La2 of phase a is reversely connected in series with the first segment coil Lb1 of the b phase, and the second segment coil Lb2 of the b phase The first segment coil Lc1 of the c phase is reversely connected, and the second segment coil Lc2 of the c phase is reversely connected in series with the first segment coil La1 of the a phase, so that the low voltage windings of the three phases a, b, and c exhibit a zn junction.

At this time, as shown in FIG. 1, the high-pressure transition vacuum interrupter Kg and the star-connected vacuum interrupter K1 in the high-voltage coil switching system of each phase are in a closed state, and the corner-connected vacuum interrupter K2 is in the open state. State, the three-phase high voltage coil is star-connected;

When it is necessary to switch the capacity of the transformer to a large capacity, the permanent magnet mechanism in the volume adjustment switch acts upward or downward once, and the transmission device drives each vacuum interrupter in the low voltage coil switching system and the high voltage coil switching system to operate according to the following sequence. :

(Firstly, the operation process of each vacuum interrupter of the low-voltage coil switching system is described. At the same time, the actions of the respective vacuum interrupters of the high-voltage coil switching system are simultaneously performed, which will be described later); at this time, the low-voltage coil switching system Each vacuum interrupter of each phase will operate according to the following sequence: firstly, the low-voltage transitional vacuum interrupter Kg is opened, the transition resistance R is turned on, as shown in FIG. 6; when the low-voltage transitional vacuum interrupter Kg is extinguished After the arc, the first parallel vacuum interrupter Kb1, the second parallel vacuum interrupter Kb2, and the third parallel vacuum interrupter Kb3 are all closed, as shown in FIG. 7; then the series vacuum interrupter Kc is divided. a gate, as shown in FIG. 8, the first parallel vacuum interrupter Kb1, the second parallel vacuum interrupter Kb2, and the third parallel vacuum interrupter Kb3 are in a closed state, and the series vacuum interrupter Kc and the low-voltage transitional vacuum interrupter Kg are in a state of opening, and the first-stage coil and the second-stage coil in each phase of the transformer low-voltage winding are connected in parallel; the three phases are thus cyclically connected to form a new winding, and then the star is pressed. The coupling method connects the three-phase windings to obtain the yn connection of the low-voltage windings; by setting five vacuum interrupters, it is ensured that the low-voltage windings are reliably extinguished by the zn coupling to the yn coupling in the case of uninterrupted current. The purpose of switching capacity.

As shown in FIG. 13 , it is an operation timing diagram of each vacuum interrupter in the switching process of the low-voltage coil switching system; specifically, the time when the permanent magnet mechanism is operated once is divided into four time periods T1-T4, and the permanent magnet mechanism Whenever it is operated once, the arc extinguishing place needs to be considered in the whole process, that is, when the vacuum interrupter is closed to open, and the arc generated by the vacuum interrupter from the opening to closing is negligible. ;

Specifically, at time T1, Kg starts from closing to opening, while during T1-T3, Kg is used for arc extinguishing; when reaching time T3, Kg has enough time to achieve reliable arc extinguishing, ie Kb1, Kb2, Kb3 can be operated from opening to closing, (the arc generated during the opening to closing is negligible), so the time interval of T3-T4 can be set very short, It can be known that after a short pause, when the time reaches T4, Kc is closed to open, and the conversion is completed. It can be seen from Fig. 13 that during the entire conversion process, it is only necessary to extinguish the arc in the low-pressure transitional vacuum interrupter Kg from closing to opening, and the operation of Kb1, Kb2, and Kb3 from opening to closing requires almost no time. To extinguish the arc, we can allocate most of the time to the Kg arc extinguishing, that is, the T2-T3 in Figure 13 can be set longer, while ensuring the effective arc extinguishing, and also ensuring the arc extinguishing time of the entire switching process. In a very short range.

Conversely, when it is necessary to convert the three-phase low-voltage coil from the yn junction to the zn junction, taking one phase as an example, the steps are as follows: the series vacuum interrupter Kc is closed first; then the first parallel vacuum interrupter Kb1, the second The parallel vacuum interrupter Kb2 and the third parallel vacuum interrupter Kb3 are opened; finally, the low-pressure transition vacuum interrupter Kg is closed, and the conversion is completed, and other details are not described again;

While driving the vacuum interrupter of the low-voltage coil switching system, the driving mechanism also drives each vacuum interrupter in each phase of the high-voltage coil switching system to operate according to the following sequence:

First, the high-pressure transitional vacuum interrupter Kg is opened; then the corner-connected vacuum interrupter K2 is closed; then the star-connected vacuum interrupter K1 is opened; finally, the high-pressure transitional vacuum interrupting Kg is opened to complete the conversion; When the high voltage coil is required to be converted from a corner to a star, the steps are reversed.

In summary, the load-carrying transformer of the present invention can realize that the winding of the transformer realizes the Yzn11 coupling mode when in a small capacity state; when switching to a large capacity, the winding of the transformer realizes the Dyn11 coupling mode.

The two-stage coil structure of the low-voltage winding makes the low-voltage winding of the tunable transformer realize the transition from yn junction to zn junction or zn junction to yn junction; the capacity transformer has small capacity and adopts Yzn11 coupling, which has strong bearing capacity. Unbalanced load capability, that is, strong single-phase power supply capability, which is especially suitable for places where three-phase load is difficult to balance (such as rural and mountainous areas). At the same time, the low-voltage side uses a two-stage coil combination to achieve switching to small In the capacity, the zn connection mode of the low-voltage winding has good lightning-proof characteristics, and is particularly suitable for use as a lightning protection transformer in areas with multiple mines or areas with high soil resistivity.

The low-voltage side winding of the present invention is divided into two sections having the same number of turns, and the number of turns can be arbitrarily determined, so that the design of the most material-saving material can be selected, and the two-stage windings are easily arranged so that the window filling factor is high. These factors lead to the fact that in the special case of the transformer, the cost of the Yzn11-coupled transformer is lower than that of the Yyn0.

Furthermore, the modulating switch adapted to the invention adopts a vacuum interrupter to form a high-voltage winding switching system and a low-voltage winding switching system, which effectively solves the arc-extinguishing problem on the high-voltage side and the low-voltage side, is maintenance-free and has a long service life; As a driving mechanism, the magnetic mechanism has a simple structure, high reliability, and the switching action is completed rapidly, and the duration of the operating overvoltage generated by the switching and the duration of the voltage waveform distortion are correspondingly shortened. In addition, in the embodiment, all the vacuum interrupters are vacuum tubes with dynamic and static contacts, and the reliability thereof is high, and the arc extinguishing can be effectively performed.

In addition, a brief description will be given of the switching process of each vacuum interrupter under another structure, as shown in FIG. 9 is a circuit diagram of the low-voltage winding side when the transformer is in a large capacity state, when it is required to switch to a small capacity, The driving mechanism drives each vacuum interrupter to operate according to the following sequence: first, the low-voltage transition vacuum interrupter Kg is closed; then the first parallel vacuum interrupter Kb1, the second parallel vacuum interrupter Kb2, and the third parallel vacuum are extinguished The arc chamber Kb3 is opened; then the series vacuum interrupter Kc is closed; finally, the low voltage transition vacuum arc extinguishing is opened, so that the low voltage winding completes the conversion from the yn junction to the zn junction, as shown in FIG. The low voltage winding is zn coupled.

The structure of Figures 11 and 12 is similar to that of Figures 9 and 10, and the specific switching process will not be described herein.

It will be apparent that the described embodiments are only a part of the embodiments of the present invention, and not An embodiment of the department. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

Claims

A lightning protection type load-carrying transformer, comprising a low-voltage winding, a high-voltage winding and an on-load capacity-adjusting switch for switching a transformer between large and small capacity, wherein: the on-load capacity-adjusting switch is switched When the capacity transformer is in a large capacity state, the winding adopts a Dyn11 coupling mode; when the load adjustment switch switches the volume modulation transformer to a small capacity, the winding adopts a Yzn11 coupling manner.
A lightning protection type load regulating transformer according to claim 1, wherein said load regulating switch comprises a high voltage switching system and a low voltage switching system, and said low voltage switching system comprises a first parallel connection in each phase. a vacuum interrupter, a second parallel vacuum interrupter, a third parallel vacuum interrupter, a series vacuum interrupter, and a low pressure transition vacuum interrupter.
A lightning protection type load-carrying transformer according to claim 2, wherein said low-voltage transitional vacuum interrupter has a transition resistor connected in parallel.
A lightning protection type load-carrying transformer according to claim 2, wherein said low-voltage transitional vacuum interrupter is connected in series with a transition resistor.
A lightning protection type load regulating transformer according to claim 2, wherein: said first parallel vacuum interrupter, said second parallel vacuum interrupter, and said third parallel vacuum interrupter are In the gate state, when the series vacuum interrupter and the low-voltage transition vacuum interrupter are in the open state, the two sets of coils in each phase of the transformer low-voltage winding are connected in parallel;

When the series vacuum interrupter is in a closed state, and the first parallel vacuum interrupter, the second parallel vacuum interrupter, the third parallel vacuum interrupter, and the low pressure transition vacuum interrupter are in an open state, a set of phases in a low voltage winding of a transformer The coil is in reverse series connection with a set of coils of another phase.
The lightning protection type load-carrying transformer according to claim 2, wherein each of the vacuum interrupters operates according to the following sequence:

First, the low-pressure transition vacuum interrupter is opened;

Then, the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third parallel vacuum interrupter are all closed;

Finally, the series vacuum interrupter is opened, so that the low voltage winding of the transformer completes the conversion from zn junction to yn junction.
An on-load capacity-adjusting switch having a first state and a second state, comprising a high-voltage switching system and a low-voltage switching system, wherein: when the volume-adjusting switch is in the first state, the transformer winding is in a Dyn11 coupling mode; When the adjustment switch is in the second state, the transformer winding is in the Yzn11 coupling mode.
The on-load capacity adjustment switch according to claim 7, wherein each phase of the low-voltage switching system comprises a first parallel vacuum interrupter, a second parallel vacuum interrupter, and a third parallel vacuum interrupter. Room, series vacuum interrupter and transitional vacuum interrupter with series resistance in series.
The on-load capacity adjustment switch according to claim 7, wherein each phase of the low-voltage switching system comprises a first parallel vacuum interrupter, a second parallel vacuum interrupter, and a third parallel vacuum interrupter. Room, series vacuum interrupter and transitional vacuum interrupter with transition resistance connected in parallel.
A load-carrying switch according to claim 8 or 9, wherein:

When the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third The combined vacuum interrupter is in a closed state, and when the series vacuum interrupter and the low-voltage transition vacuum interrupter are in an open state, the two sets of coils in each phase of the transformer low-voltage winding are connected in parallel;

When the series vacuum interrupter is in a closed state, and the first parallel vacuum interrupter, the second parallel vacuum interrupter, the third parallel vacuum interrupter, and the low pressure transition vacuum interrupter are in an open state, A set of coils of one phase of the low voltage winding of the transformer is placed in reverse series connection with a set of coils of the other phase.
The on-load capacity adjustment switch according to claim 8, wherein each of the vacuum interrupters operates according to the following sequence:

First, the low-pressure transition vacuum interrupter is closed;

Then, the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third parallel vacuum interrupter are all opened;

Then closing the series vacuum interrupter;

Finally, the low-voltage transition vacuum arc-extinguishing is opened, so that the low-voltage winding of the transformer completes the conversion from the yn junction to the zn junction.
The on-load capacity adjustment switch according to claim 9, wherein each of the vacuum interrupters operates according to the following sequence:

First, the low-pressure transition vacuum interrupter is opened;

Then, the first parallel vacuum interrupter, the second parallel vacuum interrupter, and the third parallel vacuum interrupter are all closed;

Finally, the series vacuum interrupter is opened, so that the transformer low voltage winding completes the conversion from yn junction to zn junction.