JPH023528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum switch type on-load tap changer, and more particularly to a configuration of a switching switch of a vacuum switch type on-load tap changer that uses a vacuum switch as a current switching element.

Conventionally, parallel-cutting contacts that open and close in insulating oil have been used in on-load tap changers. Vacuum switch-type on-load tap changers that use vacuum switches as current switching elements have been developed and put into practical use in recent years, and have numerous advantages for improving the performance of on-load tap changers. Under these circumstances, in order to further improve the reliability of the main functions of the switching switch that makes up the on-load tap changer, which is the interruption and withstand voltage between poles,
As shown in Figures 1 and 3 of the attached drawings, the main contact of the on-load tap changer, which requires the most reliability, is constructed by connecting two vacuum switches in series. is proposed. Note that FIGS. 2 and 4 show the switching sequence of each contact of the switching switch shown in FIGS. 1 and 3 above.

To explain FIGS. 1 to 4, reference numerals 1,
9 is the vacuum switch for the main contact on the odd tap side, 2, 8
Vacuum switch for even tap side main contact, 3a, 3
b is a vacuum switch for auxiliary contacts, 4 is a current limiting resistor,
5 is a transformer tap winding, 6 is an odd tap selector, and 7 is an even tap selector.

By configuring the main contacts of the circuit configured in this way by connecting two vacuum switches in series, an on-load tap changer with improved breaking capacity, improved withstand voltage between electrodes, and improved main functions can be achieved. Various advantages can be obtained, such as improved reliability of the vacuum switch and a reduction in the incidence of tap changer accidents (short circuits between taps) during load due to poor vacuum level of the vacuum switch. A problem occurs. (1) The number of vacuum switches used increases.

(2) The number of mechanisms increases, increasing the overall cost of the on-load tap changer.

(3) The external dimensions of the switching switch of the on-load tap changer, that is, the planar projected dimensions, become larger.

(4) As the external dimensions of the on-load tap changer increase, the planar external dimensions of the transformer also increase.

(5) As the external dimensions of the transformer increase, the cost of the transformer also increases.

The present invention eliminates the disadvantages of using two vacuum switches for the main contacts, and provides a vacuum switch type that has little effect on the external dimensions of the transformer and has improved various capabilities and reliability. The object of the present invention is to provide an on-load tap changer.

In order to achieve the above object, the present invention provides a first vacuum switch in which one of the electrodes of the two main contact vacuum switches is connected to the neutral point side, and
The first changeover switch part is configured such that the auxiliary contact vacuum switch is arranged in the same plane and the predetermined opening/closing operation is performed by a single cam plate, and the main contact vacuum switch has an odd or even number of electrodes. A second vacuum switch connected to the tap is disposed concentrically on a different plane from the first switch section, and is configured to perform predetermined opening/closing operations using a cam plate different from the cam plate of the first switch section. The changeover switch of the changeover switch is constructed from the second changeover switch section.

Before explaining the present invention, a conventional resistive on-load tap changer related to the present invention will be described below.

Generally, a resistance type on-load tap changer has an embedded structure as shown in FIG. 5 of the accompanying drawings. That is, in the figure, numeral 10 is a transformer;
11 is a transformer core, 12 is a transformer winding, 13 is a transformer tank, 14 is a drive device for a load tap changer, 15 is a drive shaft thereof, 16 is a drive direction conversion mechanism, and 17 is a switching switch inside. 18 is a tap selector, 19 is a tap lead, and 20 is a load tap changer,
In addition, L is the transformer tank 1 of the on-load tap changer.
3 is the length of the storage section, D is the external dimension of the switching switch, and E is
indicates the equivalent external dimensions of the tap selector.

In the case of a resistive on-load tap changer having such an embedded structure, the height of the transformer core 11 is generally sufficiently higher than the storage length L of the on-load tap changer. The length L has almost no effect on the external dimensions of the transformer. However, the external dimensions D of the switching switch and the equivalent external dimensions E of the tap selector are generally ED due to the high voltage applied to the tap selector, from the standpoint of insulation technology, and the storage length L Since it is not dependent on the internal components of the transformer, the size of the external dimensions D and E directly affects the planar dimensions of the transformer. That is,
When considering the configuration of a built-in vacuum switch type on-load tap changer, how to configure the external dimension D of the switching switch chamber to be equal to or smaller than the external dimension E of the tap selector depends on the external dimension of the transformer. This is an important key to controlling costs.

An example of the vacuum switch driving method, which is one of the important factors determining the external dimension D, is shown in the attached drawing, FIG. 31 is a drive shaft that is connected to a quick cut mechanism (not shown) and rotates clockwise and counterclockwise; 32 is a cam that is connected to the drive shaft 31 by a key (not shown) and has a shape that gives a certain sequence to each vacuum switch; 33 34 is a device that transmits the vertical movement of the bell crank 33 to the movable electrode of the vacuum switch and causes the vacuum switch to perform predetermined opening/closing operations. , a vacuum switch unit consisting of a device supporting a vacuum switch and a vacuum switch, 35
indicates the mounting base of these elements.

Now, in a three-phase switching switch using the vacuum switch driving method shown in FIG. 6, one of the vacuum switches 8 and 9 for the main contacts of the vacuum switches constituting the main contacts shown in FIG. Let us compare the cross-section of the circuit shown in FIG. 6 in which the circuit is not connected with the cross-section of the circuit consisting of two main contact vacuum switches as shown in FIG.

Figure 7 of the attached drawing is a cross-sectional view of a case where the vacuum switches 8 and 9 for the main contacts shown in Figure 1 are not provided, and Figure 8 of the attached drawing is a sectional view of the two main contacts as shown in Figure 1. FIG. 2 is a cross-sectional view of a circuit provided with a vacuum switch. Note that the symbols in FIGS. 8 and 9 are the same as those shown in FIGS. 1 and 6.

As is clear from the figure, in the case of the circuit shown in FIG. 8, the external dimensions of the switching switch chamber, that is, the external diameter dimension D of the insulating tube 30 in the above example, are considerably larger than those in the case of FIG. 7. Therefore, the relationship DE cannot be satisfied, and as a result, the overall coordination breaks down. You will have to pay the price shown in (1) to (5) below.

The object of the present invention is to provide a vacuum switch type on-load tap changer that has high performance and high reliability without paying such a price.

Hereinafter, the present invention will be explained based on the accompanying drawings FIGS. 9 and 10 showing one embodiment thereof.

Prior to explaining the present invention, the reasons for constructing the present invention will be explained as follows.

The switching switch of a vacuum switch type on-load tap changer is generally composed of the following elements.

In other words, there is a quick switching mechanism section for rotating the switching switch at high speed, a switching section (corresponding to Fig. 6) consisting of a current switching element (vacuum switch) and its drive mechanism, and a section that limits the tap winding current. It is composed of three main elements of a current limiting resistor section having a current limiting resistor.

In such a configuration, in order to obtain a switching switch with the same external dimensions as the conventional circuit in which the main contact vacuum switches 8 and 9 shown in FIGS. 1 and 3 are not provided, newly added The entire vacuum switch including the main contact vacuum switches 8 and 9 cannot be arranged on the same plane as shown in FIG. Therefore, in the present invention, a vacuum switch in which one of the electrodes is connected to the neutral point side, that is, a main contact vacuum switch 1 shown in FIG.
2 and vacuum switches 3a and 3b for auxiliary contacts are arranged on the same plane, and a vacuum switch with one of the electrodes connected to the tap side, that is, vacuum switches 8 and 9 for main contacts shown in FIG. The vacuum switches, namely vacuum switches 1, 2,
3a and 3b, the vacuum switch shown in FIGS. 1 and 3 has the same external dimensions as a switching switch having a circuit in which the main contact vacuum switches 8 and 9 are not provided. It is possible to obtain a switching switch having a circuit in which two switches are provided in series to constitute a main contact.

Note that, unlike the above configuration, main contact vacuum switches 8, 9 and auxiliary contact vacuum switches 3a, 3b
Even if the main contact vacuum switches 1 and 2 are placed on the same plane and the main contact vacuum switches 1 and 2 are placed on different planes, the external dimensions are
Although it is possible to make the external dimensions almost the same as those shown in Figure 7, as is clear from the circuits in Figures 1 and 3, the connection points of the vacuum switch electrodes are different, so the switching switch Therefore, it is desirable to arrange the vacuum switches 1 and 2 for the main contacts and the vacuum switches 3a and 3b for the auxiliary contacts on the same plane.

If configured as described above, the external dimensions can be the same as the conventional one, but regarding the length L of the storage part shown in FIG. It will be longer depending on the placement. However, the plane area required for this is not very wide because only two vacuum switches are arranged per one unit, that is, a total of six vacuum switches. .
It is possible to keep it to a minimum.

The vacuum switch type on-load tap changer according to the present invention, which is constructed based on the above-mentioned reasons, will be explained with reference to the attached drawings, FIGS. 9 and 10, which show one embodiment thereof. Note that FIG. 10 shows the cross section of FIG. 9, and the cross section of FIG. 9 is the same as that of FIG. 7.

In FIG. 9 and FIG. 10, reference numeral 100 is a switching switch, 101 is an early switching mechanism section, 102 is a first switching section in which the main contact vacuum switches 1 and 2 and the auxiliary contact vacuum switch 3a are arranged; 103
is the second one where the main contact vacuum switches 8 and 9 are arranged.
The changeover switch section, 104 is a current limiting resistor section, 31 is an insulated drive shaft, 105 is an insulated support, 106 is a current limiting resistor support plate, and the second changeover switch section 103 and the current limiting resistor are The support plate 106 is a support member (not shown) and is a support member not shown in the drawings.
It is attached to 02. Note that other symbols are the same as those shown in FIGS. 1 and 6.

As described above, the device of the present invention is shown in FIGS. 1 and 3.
By configuring a vacuum switch-type on-load tap changer having a circuit in which two vacuum switches are connected in series to the main contacts as shown in FIGS. 7, 9, and 10, The following effects can be obtained. That is, (1) a vacuum switch type on-load tap changer with extremely high performance and reliability can be constructed with approximately the same external dimensions as conventional ones.

(2) Although the cost of the on-load tap changer increases slightly, the performance and reliability more than compensate for the increased cost.

(3) The external dimensions of the transformer do not change, so there is no impact on transformer cost.

(4) The ratio of the cost of the on-load tap changer to the transformer cost is about 10% at most, and therefore, since the external dimensions of the transformer do not change, the overall cost of the transformer with the on-load tap changer is approximately 10%. By minimizing the increase in overall performance,
Reliability can be improved.

(5) By arranging the first changeover switch part 102, the second changeover switch part 103, and the current limiting resistor part 104 with respect to the early switching mechanism part 101 as shown in FIGS. 9 and 10, the changeover switch Wiring inside is easier.

In the above embodiment, the current limiting resistor 4 and the auxiliary contact vacuum switch shown in FIG. 1 have been described as having a circuit provided only for one of the main contacts. A circuit having a circuit provided at the main contact can be arranged in exactly the same manner, and even in that case, the same effects as in the above embodiment can be obtained.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of an example of a vacuum switch type on-load tap changer, Figure 2 is a switching sequence diagram of each contact in Figure 1, and Figure 3 is another example of a vacuum switch type on-load tap changer. The circuit diagram, Fig. 4 is a switching sequence diagram of each contact point in Fig. 3, Fig. 5 is an explanatory diagram for installing an embedded load tap changer to a transformer, and Fig. 6 is an example of a vacuum switch drive device. A sectional view, FIG. 7 is an explanatory cross-sectional view taken by the − line in FIG. 6 when three vacuum switches are arranged per one vacuum switch, and the − line in FIG. 9, and FIG. 8 is a sectional view corresponding to one in FIG. 6. FIG. 9 is a cross-sectional view taken along the - line when five vacuum switches are arranged, and FIG. Configuration explanatory diagram of the embodiment, No. 10
The figure is an explanatory cross-sectional view taken along the cross-section line in FIG. 9. 1, 2, 8, 9... Vacuum switch for main contact, 3
a, 3b... Vacuum switch for auxiliary contact, 30...
Insulating tube, 31... Insulating drive shaft, 32... Cam plate,
34...Vacuum switch unit, 100...Switching switch, 101...Quick cut mechanism section, 102...First
Changeover switch section, 103... Second changeover switch section, 104... Current limiting resistor section, 105... Insulating support, 106... Current limiting resistor support plate. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. The main contact and auxiliary contact of the arcing contact of a resistive load tap changer having a quick-cutting mechanism are constituted by a vacuum switch, and the arcing contact is constituted by a vacuum switch, and there is a limit between the odd or even number tap and the neutral point. A vacuum switch is constructed by connecting two main contacts in series that are connected without passing through a flow resistance, and a vacuum switch is provided in parallel with the main contacts and limited between an odd or even tap and a neutral point. In a vacuum switch type on-load tap changer equipped with a vacuum switch for an auxiliary contact connected in series with a current resistance, one of the electrodes of the two vacuum switches of the main contact is connected to the neutral point side. a first vacuum switch for the auxiliary contact, and a first switching switch section configured to arrange the vacuum switch for the auxiliary contact in the same plane and perform predetermined opening/closing operations using a single cam plate; Of the vacuum switches, a second vacuum switch whose electrodes are connected to odd or even taps is disposed concentrically on a plane different from the first switch section, and a cam plate different from the cam plate of the first switch section. A vacuum switch type on-load tap changer, characterized in that a changeover switch of the changeover switch is constituted by a second changeover switch section configured to perform a predetermined opening/closing operation. 2. The vacuum switch type on-load tap changer according to claim 1, wherein the changeover switch is configured in this order: an early switching mechanism section, a first changeover switch section, a second changeover switch section, and a current limiting resistor section. . 3. The vacuum switch type on-load tap changer according to claim 2, wherein the second changeover switch part and the current limiting resistor part of the changeover switch are arranged on substantially the same plane.