CN207367770U - A kind of new capacitance-adjustable transformer - Google Patents

Abstract

The utility model discloses a novel capacity regulating transformer, which includes a low-voltage winding, a high-voltage winding and a capacity regulating switch. The capacity regulating switch includes a high-voltage coil switching system and a low-voltage coil switching system. When it is in a state of large capacity, the winding is Dy connection mode; when in a small capacity state, the winding is a Dy connection mode, and the high-voltage coil switching system includes a first high-voltage vacuum interrupter, a second high-voltage vacuum interrupter, a first high-voltage transitional vacuum interrupter and a first high-voltage transitional vacuum interrupter. A second high-voltage transitional vacuum interrupter with a transition resistor is connected in parallel, and the first high-voltage vacuum interrupter is connected in series with the second high-voltage vacuum interrupter. The Dy/Dy capacity adjustment conversion method has a ratio of no-load loss of high capacity to low capacity of about 4:1, and its no-load loss at low capacity is lower, so it is especially suitable for peak-to-valley differences in power consumption. occasion application. The use of vacuum interrupter to achieve capacity adjustment can effectively solve the problem of arc extinguishing, the overall structure is simple, and the on-load capacity adjustment is realized.

Description

A New Type of Capacitance Adjusting Transformer

technical field

The utility model belongs to the technical field of transformer equipment in the electric power industry, in particular to a novel capacity regulating transformer.

Background technique

In occasions where there is a large difference between peak and valley power consumption, such as office buildings and other office spaces, commercial cities, development zones and tourist areas, etc., there are obvious time-period loads, and the load rate during working hours is high, while the load rate during non-working hours is very low. ; In order to curb the frequent occurrence of winter smog in the north, some areas have vigorously promoted the conversion of coal to electricity, and introduced the "peak and valley electricity price subsidy policy" from 9:00 pm to 6:00 am, making the peak load rate of electricity consumption in winter as high as 70-85% , and the peak load rate of electricity in summer may only be 20-30%, and the load rate in spring and autumn is as low as 10%. In these occasions, if the traditional capacity adjustment method is adopted, the no-load loss at low capacity will be very high.

There is an urgent need to provide a new type of capacity regulating transformer to adapt to occasions where the difference between peak and valley power consumption is large.

Utility model content

In view of the above problems, the utility model provides a novel capacity-adjusting and voltage-regulating transformer with low no-load loss when the capacity is low.

In order to achieve the above purpose, the utility model adopts the following technical solutions: a new capacity regulating transformer, which includes a low voltage winding, a high voltage winding and a capacity regulating switch, and the capacity regulating switch includes a high voltage coil switching system and a low voltage coil switching system. In the capacity state, the winding is in the Dy connection mode; in the small capacity state, the winding is in the Dy connection mode, and the high-voltage coil switching system includes a first high-voltage vacuum interrupter, a second high-voltage vacuum interrupter, and a second high-voltage vacuum interrupter. A high-voltage transitional vacuum interrupter and a second high-voltage transitional vacuum interrupter connected in parallel with a transition resistor, the first high-voltage vacuum interrupter and the second high-voltage vacuum interrupter are connected in series. The Dy/Dy capacity adjustment conversion method has a ratio of no-load loss of high capacity to low capacity about 4:1. Compared with other capacity adjustment conversion methods, its no-load loss at low capacity is lower, so it is especially It is suitable for applications where there is a large difference between peak and valley power consumption. The vacuum interrupter is used to realize capacity adjustment, which can effectively solve the problem of arc extinguishing, and the overall structure is simple, which realizes on-load capacity adjustment.

Further, the low-voltage coil switching system includes a first low-voltage vacuum interrupter, a second low-voltage vacuum interrupter, a first low-voltage transitional vacuum interrupter, and a second low-voltage transitional vacuum interrupter connected in parallel with a transition resistor, The first low-voltage vacuum interrupter is connected in series with the second low-voltage vacuum interrupter.

Further, the high-voltage winding includes a first high-voltage winding and a second high-voltage winding. When the capacity is large, the first high-voltage winding and the second high-voltage winding are connected in parallel; when the capacity is small, the first high-voltage winding and the second The high voltage windings are connected in series.

Further, the low-voltage winding includes a first low-voltage winding and a second low-voltage winding. When the capacity is large, there is a low-voltage winding between the first low-voltage winding and the second high-voltage winding; when the capacity is small, the first low-voltage winding and the second The low voltage windings are connected in series.

Further, it also includes a voltage regulating winding, the input end of the voltage regulating winding is connected with the output end of the high voltage winding. In the same phase, the voltage regulating winding is connected to the common output end of the two groups of coils, and then only one tap needs to be set for each phase, and the voltage of the two groups of coils can be adjusted at the same time. The quantity, the structure is simpler, and the pressure regulation is more stable.

Further, the voltage regulating winding includes a first voltage regulating winding, and the magnetic flux of the first voltage regulating winding is opposite to that of the high voltage winding. In the opposite magnetic flux setting, the magnetic flux generated by the first voltage regulating winding cancels a part of the magnetic flux of the high voltage winding to achieve the effect of stepping down; compared with the traditional mechanical voltage regulation, it is necessary to ensure the number of voltage regulation turns between the two sets of coils Equally difficult, through the offset method of the opposite magnetic flux, the boosting method is safer, and the voltage regulation setting structure is simpler, so that the Dy/Dy capacity regulating transformer can be realized;

Further, the voltage regulating winding includes a second voltage regulating winding, and the magnetic flux of the second voltage regulating winding is the same as that of the high voltage winding. With the same magnetic flux setting, the magnetic flux generated by the first voltage regulating winding is superimposed on the magnetic flux of the high voltage winding, so as to achieve the effect of boosting voltage.

Further, it also includes a voltage regulating switch, which includes a rated vacuum interrupter, a transitional vacuum interrupter connected in parallel with a transition resistor, and at least one boosted vacuum interrupter, the rated vacuum interrupter and The transitional vacuum interrupters are connected in series.

Further, it also includes a voltage regulating switch, which includes a rated vacuum interrupter, a transitional vacuum interrupter connected in parallel with a transition resistor, and at least one step-down vacuum interrupter, the rated vacuum interrupter and The transitional vacuum interrupters are connected in series.

In summary, the beneficial effects of the utility model are: the Dy/Dy capacity adjustment transformation mode is Dyn11 connection at low capacity, and has many advantages compared with the Dy/Yy capacity adjustment mode of Yyn0 connection at low capacity, for example, The ability to withstand unbalanced loads is much stronger than that of Yyn0 connection; it can reduce harmonic components, and the zero-sequence impedance is small, which is beneficial to the removal of single-phase ground short-circuit faults; A wide range of options can be selected, so the most economical and material-saving design can be selected, which is economical and suitable for promotion; at the same time, by setting up a vacuum interrupter to cooperate with capacity adjustment, on-load capacity adjustment is realized, making Dy/ The Dy capacity adjustment method is realized.

Description of drawings

Fig. 1 is a schematic diagram of the circuit principle of the high-voltage side winding of the utility model when the capacity is small.

Fig. 2 is a schematic diagram of the circuit principle of the high-voltage side winding of the utility model when the capacity is large.

FIG. 3 is a schematic diagram of the circuit principle of the low-voltage side winding of the utility model when the capacity is small.

FIG. 4 is a schematic diagram of the circuit principle of the low-voltage side winding of the utility model when the capacity is large.

Fig. 5 is a schematic diagram of the action sequence of each vacuum interrupter in the high-voltage side winding during the transition from low capacity to high capacity of the utility model.

Fig. 6 is a schematic diagram of the action sequence of each vacuum interrupter in the low-voltage side winding during the transition from low capacity to high capacity of the utility model.

Fig. 7 is a schematic diagram of another circuit principle of the high-voltage side winding of the utility model when the capacity is small.

FIG. 8 is a schematic diagram of another circuit principle of the high-voltage side winding of the utility model when the capacity is large.

FIG. 9 is a schematic diagram of the action sequence of each vacuum interrupter in the low-voltage side winding and the high-voltage side winding during the conversion process of the utility model from low capacity to high capacity.

Fig. 10 is another schematic circuit diagram of the high-voltage side winding of the utility model when the capacity is large.

Fig. 11 is a schematic diagram of the circuit principle of the capacity regulating switch of the present invention under the rated gear branch.

FIG. 12 is a schematic diagram of the circuit principle of the capacity regulating switch of the present invention under the step-up branch.

Fig. 13 is a schematic diagram of the circuit principle of the capacity regulating switch of the present invention under the step-down branch.

Among them, K represents the vacuum interrupter, the symbol "day" indicates that the vacuum interrupter is in the closed state, and the symbol "me" indicates that the vacuum interrupter is in the open state; R represents the transition resistance; T represents time.

Detailed ways

In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model.

A new type of capacity-regulating transformer, including a capacity-regulating switch for switching between large and small capacities of the transformer. Each phase of the transformer includes a low-voltage winding on the low-voltage side and a high-voltage winding on the high-voltage side; the capacity-regulating switch can It is to connect the three-phase windings of the transformer at the same time, and a capacity adjustment switch can be respectively set for each phase; specifically, when the capacity adjustment switch drives the three-phase windings to be in the Dy connection mode, the transformer capacity is in a large-capacity state; the capacity adjustment When the three-phase windings driven by the switch are in the Dy connection mode, the transformer capacity is in a small capacity state;

Specifically, as shown in Figures 1 and 2, the high-voltage winding includes a first high-voltage winding 11 and a second high-voltage winding 12. When the capacity is large, the first high-voltage winding and the second high-voltage winding are connected in parallel; When the capacity is high, the first high-voltage winding and the second high-voltage winding are connected in series.

Specifically, as shown in Figures 3 and 4, the low-voltage winding includes a first low-voltage winding 21 and a second low-voltage winding 22. When the capacity is large, the first low-voltage winding and the second high-voltage winding are connected in parallel; capacity, the first low-voltage winding and the second low-voltage winding are connected in series;

In this embodiment, as shown in Figure 1-2, the high-voltage winding in each phase includes two sections of coils, and the two sections of coils can be switched between parallel and series, specifically, one of the branches includes a series The connected high-voltage vacuum interrupter Kg1 and the first high-voltage winding 11, another branch includes the high-voltage vacuum interrupter Kg2 connected in series and the second high-voltage winding 12; the first high-voltage winding 11 and the second high-voltage winding 12 pass through A transition branch is connected, and the transition branch includes a high-voltage transition vacuum interrupter Kgg and a high-voltage transition series vacuum interrupter Kgc connected in series. The high-voltage transition vacuum interrupter Kgg is connected in parallel with a transition resistance Rg. The specific connection Refer to Figure 1 and 2 for the method;

The transition from Figure 1 to Figure 2 requires each vacuum interrupter to operate in the following sequence:

Kg1, Kg2 close;

Kgc opening;

The conversion from small capacity to large capacity on the high-voltage side can be realized; the specific action sequence refers to Figure 5;

In this embodiment, as shown in Figures 3 and 4, the low-voltage windings in each phase include two sections of coils, and these two sections of coils can be switched between parallel and series connection, specifically, one of the branches includes a series connection The connected low-voltage vacuum interrupter Kd1 and the first low-voltage winding 21, another branch includes the low-voltage vacuum interrupter Kd2 connected in series and the second low-voltage winding 22; the first low-voltage winding 11 and the second low-voltage winding 12 pass through A transition branch is connected, and the transition branch includes a low-voltage transition vacuum interrupter Kdg and a low-voltage transition series vacuum interrupter Kdc connected in series, and a transition resistance Rg is connected in parallel with the low-voltage transition vacuum interrupter Kdg. Refer to Figure 3 and 4 for the method;

The transition from Figure 1 to Figure 2 requires each vacuum interrupter to operate in the following sequence:

Kd1, Kd2 close;

Kdc opening;

The conversion from small capacity to large capacity on the low-voltage side can be realized; the specific action sequence refers to Figure 6;

It can be obtained through experiments: when the capacity is high and when the capacity is low, the ratio of the rated capacity is about 4:1; the ratio of the structural capacity is 2:1; the ratio of the no-load loss to the load loss is about 4:1.

As shown in Figures 5 and 6, specifically,

(1) The time between T1~T3 is the arc extinguishing time on the high voltage side; 22ms>T1~T3>10ms;

The time between T1~T2 is the arc extinguishing time of the low voltage side; 20ms>T1~T2>8ms.

(2) The time between T2~T3 is used to prevent the possibility of short-term overvoltage caused by asynchronous high and low voltage sides during series-parallel conversion, T2~T3≈2ms. In this way, the order of conversion can be guaranteed: when changing from low capacity to high capacity, the low voltage side is first connected in parallel to reduce the number of turns and reduce the voltage, and then the high voltage side is converted from series to parallel to restore the voltage; When changing to low capacity, the high-voltage side is first connected in series to reduce the voltage, and then the low-voltage side is connected in series to restore the voltage.

(3) The time between T3~T4 is the conversion transition time of the high voltage side; 5ms>T3~T4>0;

The time between T2~T4 is the conversion transition time of the low voltage side; 7ms>T2~T4>0.

The Dy/Dy capacity adjustment conversion method has a ratio of no-load loss of high capacity to low capacity about 4:1. Compared with other capacity adjustment conversion methods, its no-load loss at low capacity is lower, so it is especially Suitable for applications where there is a large difference between peak and valley power consumption;

The Dy/Dy capacity adjustment conversion method is Dyn11 connection at low capacity, which also has more advantages than the Dy/Yy capacity adjustment method that is Yyn0 connection at low capacity, for example, the ability to withstand unbalanced loads is much stronger than that of Yyn0 connection ; It can reduce the harmonic component, and the zero-sequence impedance is small, which is beneficial to the removal of single-phase grounding short-circuit faults; in addition, the number of winding turns of the Dy/Dy capacity-adjusting transformation method can be selected in a wide range, so the most economical one can be selected The most material-saving design is economical and suitable for promotion.

When the capacity of the transformer is relatively small (250kVA and below), the high-voltage line is very thin and cannot be divided into two. The circuit structures shown in Figures 7 and 8 can be considered;

For the transition from Figure 7 to Figure 8, refer to Figure 9 for the action timing diagram of each vacuum interrupter;

Further, the utility model also includes a voltage regulating switch, which includes a rated vacuum interrupter and a transitional vacuum interrupter connected in parallel with a transition resistor, and the rated vacuum interrupter is connected in series with the transitional vacuum interrupter connect. By setting up a vacuum interrupter to cooperate with the boost, the on-load voltage regulation is realized, so that the capacity regulating transformer under the Dy/Dy capacity regulation mode can realize voltage regulation. (The specific structure of the pressure regulating switch will be described later)

Further, the voltage regulating switch also includes at least one step-down vacuum interrupter and at least one booster vacuum interrupter; at least one step-up branch and step-down branch, and the vacuum interrupter is used to realize step-down. Boost.

Further, it also includes a voltage regulating winding, the input end of which is connected to the output end of the high voltage winding; the voltage regulating winding includes a first voltage regulating winding and a second voltage regulating winding. In the same phase, the voltage regulating winding is connected to the common output end of the two groups of coils, and then each phase only needs to set a tap of the voltage regulating winding to simultaneously regulate the voltage of the two groups of high voltage winding coils, without the need to separate the two groups of coils Setting taps reduces the number of taps, the structure is simpler, and the voltage regulation is more stable.

Specifically, as shown in Figures 10 and 11, the circuit schematic diagram of the high-voltage side winding in the state of large capacity; at this time, the first high-voltage winding 11 and the second high-voltage winding 12 are connected in parallel, and the common output terminal 31 of the two groups of coils is connected in parallel. The input terminal 41 of the voltage regulating winding 4, that is, the midpoint of the voltage regulating winding is connected to the X (Y, Z) end of the high voltage winding (main coil), as the rated gear branch 41, between the midpoint of the voltage regulating winding The taps are respectively led out from the two sides; the magnetic flux generated by the tap coil on one side is opposite to that of the high-voltage winding (main coil) (magnetic flux cancels), which reduces the number of turns of the high-voltage winding (main coil), and the tap coil is the second A voltage-regulating winding 51; the magnetic flux generated by the tap coil on the other side is the same as that of the high-voltage winding (magnetic flux assists), increasing the number of turns of the high-voltage winding (main coil), and the tap coil is the second voltage-regulating winding 52; In the figure, "*" is used to indicate the end with the same name, and the end without the mark is the end with the same name;

With the opposite magnetic flux setting, the magnetic flux generated by the first voltage regulating winding cancels a part of the magnetic flux of the high voltage winding to achieve the effect of voltage reduction; with the same magnetic flux setting, the magnetic flux generated by the second voltage regulating winding is superimposed on the high voltage winding The magnetic flux, in order to achieve the boost effect.

Compared with the traditional mechanical voltage regulation, which needs to ensure that the number of voltage regulation turns between the two sets of coils is equal, the utility model adopts the offset method of the opposite magnetic flux or the assistance method of the same magnetic flux, and its voltage reduction or boosting method is more efficient. Safety, and the structure of the voltage regulating setting is simpler, so that the capacity regulating transformer of Dy/Dy can be realized.

More specifically, at least one first voltage-regulating tap 511 is set in the first voltage-regulating winding 51, and at least one second voltage-regulating tap 521 is set in the second voltage-regulating winding 52, and the voltage-regulating taps form various voltage-regulating gear positions. The taps are selected through a pressure regulating switch to realize the adjustment between the various pressure regulating gears. As shown in Figure 11-13, it is a circuit diagram of one of the pressure regulating methods. K means vacuum extinguishing Arc chamber, the symbol "日" means that the vacuum interrupter is in the closed state, the symbol "目" means that the vacuum interrupter is in the open state; R represents the transition resistance, and the arrow represents the direction of voltage transmission;

In this embodiment, the voltage regulating switch includes a rated gear branch, a step-up branch and a step-down branch;

Specifically, Fig. 11 is a schematic diagram in the state of the rated gear, which includes the rated vacuum interrupter Ke, the transition vacuum interrupter Kg and the transition resistance R; the step-down branch includes the first voltage regulating tap 511 and the step-down vacuum interrupter Chamber K1; the step-up branch includes a second voltage-regulating tap 521 and a step-up vacuum interrupter K2;

Specifically, Fig. 11 is a schematic diagram in the boost state. At this time, K2 is turned on, Ke and K1 are both in the off state, and the second voltage regulating tap 521 set at the terminal with the same name as the main coil is connected to the circuit, and the second The magnetic flux generated by the voltage regulating tap 521 cooperates with the main coil to regulate the voltage;

Figure 12 is a schematic diagram of the state of the rated gear. From Figure 11 to Figure 12, each vacuum interrupter needs to operate according to the following sequence:

First K2 is connected, Ke, K1, Kg are all disconnected;

Then Ke connected;

Then K2 is disconnected;

Finally, Kg is switched on, and the voltage is smoothly adjusted from the boost gear to the rated gear. The whole process is realized by using a vacuum interrupter, and a transition branch is designed to realize the on-load voltage regulation without continuous power supply;

Figure 13 is a schematic diagram in the step-down state, from Figure 12 to Figure 13, each vacuum interrupter needs to operate according to the following sequence:

First, Ke and Kg are connected, and K1 and K2 are disconnected;

Then Kg is disconnected;

Then K1 is connected;

Finally, it can be disconnected, and the voltage is smoothly adjusted from the rated gear to the step-down gear. The whole process is realized by using a vacuum interrupter, and a transition branch is designed to realize the on-load voltage regulation without continuous power supply;

It should be noted that what is listed in Figure 11-13 is only one of the implementation cases, that is, when there is only one combination of the first tap and the second tap, obviously, we can set multiple taps as needed. A voltage regulating tap and a plurality of second voltage regulating taps; moreover, the action sequence and action realization method between each vacuum interrupter can be realized by the cooperation of various existing mechanical structures, which is not the focus of the present utility model , so it will not be repeated here.

The capacity regulating transformer adopting the Dy/Dy capacity regulating method has two sections of coils with the same number of turns as its high-voltage side winding. The voltage regulation turns of the coil are equal, and a total of 6 taps are required for the three phases, and they must be synchronized; to achieve such a voltage regulation, the voltage regulation structure will be very complicated, and it is currently impossible to realize; therefore, the Dy/Dy capacity regulation method The capacity-adjusting transformer of the present invention has not appeared on the market, but the utility model has cleverly set the voltage-regulating winding, and the magnetic fluxes of the two groups are set in opposite directions, and the step-down or Boost; the number of taps is reduced, the adjustment method is simple, and there are fewer taps for voltage regulation, so there is no need to consider the problem of equal turns of the two sets of coils; the use of vacuum interrupters makes the voltage regulation process more stable and complete, and the voltage regulation mode is convenient and reliable. The capacity regulating transformer of the Dy/Dy capacity regulating mode can be realized, and can be popularized and used on a large scale.

Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

Claims (9)

1. a kind of new capacitance-adjustable transformer, it includes low pressure winding, high-voltage winding and capacitance switch, and the capacitance switch includes height Crimping circle switching system and low-voltage coil switching system, during in large capacity state, the winding is Dy bind modes；In small During capacity status, the winding is Dy bind modes, it is characterised in that：It is true that the high-tension coil switching system includes the first high pressure Empty arc-chutes, the second high voltage vacuum interrupter, the first high pressure transition vacuum interrupter and it is parallel with the second high of a transition resistance Press through and cross vacuum interrupter, the first high voltage vacuum interrupter is connected in series with the second high voltage vacuum interrupter.

A kind of 2. new capacitance-adjustable transformer according to claim 1, it is characterised in that：The low-voltage coil switching system bag Include including the first low-voltage vacuum arc-extinguishing chamber, the second low-voltage vacuum arc-extinguishing chamber, the first low pressure transition vacuum interrupter and be parallel with one Second low pressure transition vacuum interrupter of transition resistance, the first low-voltage vacuum arc-extinguishing chamber are connected company with the second low-voltage vacuum arc-extinguishing chamber Connect.

A kind of 3. new capacitance-adjustable transformer according to claim 1, it is characterised in that：It is high that the high-voltage winding includes first Winding and the second high-voltage winding are pressed, during in large capacity, to be connected in parallel between the first high-voltage winding and the second high-voltage winding；Place It is to be connected in series when low capacity, between the first high-voltage winding and the second high-voltage winding.

A kind of 4. new capacitance-adjustable transformer according to claim 1, it is characterised in that：It is low that the low pressure winding includes first Winding and the second low pressure winding are pressed, is low pressure winding between the first low pressure winding and the second high-voltage winding during in large capacity；Place It is to be connected in series when low capacity, between the first low pressure winding and the second low pressure winding.

A kind of 5. new capacitance-adjustable transformer according to claim 1, it is characterised in that：A tap-changing windings are further included, the tune The input terminal of pressure winding is connected with the output terminal of high-voltage winding.

A kind of 6. new capacitance-adjustable transformer according to claim 5, it is characterised in that：The tap-changing windings include first and adjust The magnetic flux of pressure winding, first tap-changing windings and the high-voltage winding is opposite.

A kind of 7. new capacitance-adjustable transformer according to claim 5 or 6, it is characterised in that：The tap-changing windings include the Two tap-changing windings, second tap-changing windings are identical with the magnetic flux of the high-voltage winding.

A kind of 8. new capacitance-adjustable transformer according to claim 5, it is characterised in that：A tap changer is further included, the tune Compress switch including specified vacuum interrupter, be parallel with the transition vacuum interrupter of transition resistance and at least one boosting vacuum is gone out Arc chamber, the specified vacuum interrupter are connected in series with transition vacuum interrupter.

A kind of 9. new capacitance-adjustable transformer according to claim 5, it is characterised in that：A tap changer is further included, the tune Compress switch including specified vacuum interrupter, be parallel with the transition vacuum interrupter of transition resistance and at least one decompression vacuum is gone out Arc chamber, the specified vacuum interrupter are connected in series with transition vacuum interrupter.