JPH0775210B2 - Vacuum valve load tap changer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a load tap changer for a transformer, and more particularly,
The present invention relates to a vacuum valve type load tap changer suitable for triangular connection.

(Prior Art) Since the electric power system in Japan may have a direct grounding system, a three-phase star connection is often used for the power load tap change transformer. With the adoption of this star connection, it is most convenient to locate the transformer tap winding for voltage adjustment at the neutral point of the star connection.

The first reason is that, unlike the case where the neutral point integrated structure is adopted and the insulation between the phases is located at the line end, the insulation between the phases and between the poles may be insulation for one tap, and the insulation level is reduced. The second reason is that the operating voltage to ground is a direct grounding system, and is substantially equal to zero, so that it is easier to put together a more compact structure than the one for the line end because of the ground insulation design. For this reason, the neutral tap type is mainly used for the load tap changer.

However, depending on the electric power system, there is also a case where the triangular shape is adopted. In this case, instead of mounting the single-phase load tap changer on the three-set transformer, as shown in FIG. 10, the U-phase consisting of the main winding W _u and the tap winding TW _u , the main winding W _v and the tap. Winding T
Two-phase load tap changer LTC II consisting of W _v and V phase
In addition, connecting the single-phase load tap changer LTC I to the W-phase consisting of the main winding W _w and the tap winding TW _w requires only two load tap changers. The space for one unit can be saved, which is economically advantageous (see Japanese Examined Patent Publication No. 41-7648).

(Problems to be Solved by the Invention) By the way, in recent years, the insulating medium of the electric power equipment installed in the central part of the city has been shifting from insulating oil to insulating gas due to non-flammability due to overcrowding of the city. In response to this demand, a load tap changer has been proposed which can be used in an insulating gas. As a typical example thereof, the circuit configuration is a 2-resistor 4-valve system as shown in FIG. 9, and its structure is one using a neutral point collective type load tap changer as shown in FIG.

However, it is obvious that it is not economical to apply the neutral point batch type load tap changer for two-phase or single-phase as it is for triangular connection, because one or two phases are played. Is. Therefore, if this three-phase neutral point all-in-one type can be partially improved and produced for triangular connection, it will be an economically advantageous application method. From this point of view, in the cam switch type switching switch of FIG. 7, when the cam 27 has a three-phase configuration, vacuum valves (H
A, HB, WA, WB) are arranged, and the opening / closing operation is performed by the rotation of the drive shaft 26 due to the releasing force of the energy storage device. However, if the three-phase device is simply a two-phase device or a single-phase device, the vacuum valve and the drive mechanism are eliminated, so that the cam 27 has a wavy motion due to the imbalance of the load, and a smooth rotational motion cannot be obtained.

The details of the prior art will be described below with reference to FIGS. 7 to 9.

In FIG. 7, 20 is a head attached to a transformer cover (not shown), 21 is a gear device that vertically receives the power from an electric operating mechanism (not shown), and 22 transmits the power of the gear device 21 to the energy storage device 23. A plurality of insulating shafts 24 are provided as insulating columns, and support rods 25 support energy storage device 23 and blocking mechanism 30 suspended below the energy storage device 23.

Reference numeral 26 is a drive shaft that rotates by receiving the urging force from the energy storage device 23, and sets the main valves HA, HB and the resistance valves WA, WB to predetermined positions via the cam 27, the roller 28, and the linear guide bearings 4, 4 '. The opening and closing operations are performed according to the order. 29 is a rod, linear guide bearing
4, 4'and the movable contact shafts of main valves HA, HB and resistance valves WA, WB are connected.

Further, 1 is a neutral point conductor having a tightening portion for fixing the neutral point lead-out terminal N and the main valves HA, HB to the accumulator 23 and the support rod 25.
Fixed by. 2, 2'are flat braided wires connected to the movable contacts of the main valves HA, HB and resistance valves WA, WB, and connected to the connecting conductor 3, and the energization paths from the main valves HA, HB to the resistance valves WA, WB Is formed. Reference numeral 5 denotes a metal bearing plate, which is provided with linear guide bearings 4 and 4'which guide the movable contacts of the main valves HA and HB and the resistance valves WA and WB so as to face each other in the vertical direction, and to prevent the cam 27 from rotating. Guide the linear motion through rollers 28. 7A and 7B are connection terminals attached to the fixed contacts of the resistance valves WA and WB. Further, 6 is an insulating panel, to which the connection terminals 7A and 7B are attached, and a convex portion for vertical creeping insulation is provided between the connection terminals 7A and 7B to insulate between the taps and between the phases, and in the central portion thereof. It has a bearing 6A for the drive shaft 26.

FIG. 8 is a detailed view of the linear guide bearings 4, 4 ', FIG. 8 (a) is a plan view, and FIG. 8 (b) is a longitudinal sectional view. In these figures, 31 is a mounting base on which a linear bearing 32 is mounted, which is fixed to the bearing plate 5 with bolts 37. The linear bearing 32 includes a rail 38 and a bearing 39 having a ball rolling on the raceway surface of the rail 38, and the rail 38 is fixed to the mount 31 by a bolt 35. The bearing 39 can move linearly on the rail 38 in the vertical direction of FIG. A spring mount 36 is fixed to the bearing 39 by a bolt 34, and a roller 28 is provided on the lower tongue. The tap selectors M1 and M2 are connected to the taps T1 and T2 of the tap winding TW as shown in FIG.

Next, the operation of the conventional load tap changer will be described.

Rotation in an up or down direction of an electric operating mechanism (not shown) is transmitted to the gear device 21 via a transmission shaft (not shown),
Further, a power storing operation is applied to the power storing device 23 via the insulating shaft 22. When the stored force reaches a predetermined value, the stored force is released, and the released force is converted into rotational movement to rotate the drive shaft 26. Due to this rotation, the cam 27 rotates to cause the linear guide bearings 4 and 4'to move linearly upward and downward in accordance with the displacement of the groove provided on the outer peripheral portion, so that the main valves HA, HB and the resistance valves WA, The WB is configured to be switched in a predetermined order.

Since the wipe rod 29 is connected to the movable shafts of the vacuum valves HA, HB, WA, WB respectively, the wipe rod 29 moves up and down according to the rotating motion of the cam 27, and the vacuum is generated via the linear guide bearings 4, 4 '. Open and close valves HA, HB, WA, WB. FIG. 5 (a) is a diagram showing the change of the groove 27a of the cam 27 by 360 ° and showing the mounting and load states of the vacuum valves HA and HB of the three-phase device. As shown in the drawing, the vacuum valves HA and HB are uniformly arranged in three phases on the circumference of 360 °, so that the rotary movement of the cam 27 is smoothly performed.

(Problems to be solved by the invention) By the way, in the switching switch of the load tap changer of the neutral point all-in-one type, when the cam 27 shown in FIG. HA, HB, WA, WB are arranged so stable rotation can be obtained.
In the case of a vacuum valve for one phase and a vacuum valve for two phases in the case of a single-phase device, that portion becomes an empty phase, and if left as it is, the load of the wipe spring 33 becomes unbalanced and an unbalanced load acts, causing the cam 27 Has a wavy motion, and it is not possible to obtain smooth rotation, which causes a change in switching time.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a load tap changer including a cam mechanism capable of obtaining a smooth rotational movement in both a two-phase device and a single-phase device. It is in.

[Structure of the Invention] (Means and Actions for Solving the Problems) In order to achieve the above object, the present invention has a structure in which a plurality of vacuum valves are arranged on a plane and a three-phase structure is provided by a groove cam provided at the center thereof. In a vacuum valve type switching switch for tap switching under load, which is configured to perform switching at the same time, an outer peripheral portion of the groove cam is provided in a portion that becomes an empty phase of a three-phase configuration when configuring a two-phase device or a single-phase device. And a wavy motion suppressing device including a rolling member in contact with the rolling member and a spring-type shock absorber for pressing the rolling member against the outer peripheral portion of the groove cam.

According to the switching switch for a vacuum valve type load tap changer of the present invention, since the wavy motion suppressing device is arranged in the empty phase portion of the vacuum valve, smooth rotational motion is achieved in both the two-phase device and the single-phase device. Is obtained.

(Example) The Example of this invention is described with reference to drawings.

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

In the figure, reference numeral 26 designates a drive shaft, which is rotated by receiving a releasing force from the energy storage device 23 as shown in FIG. 7, and is driven by a main valve HA, via a cam 27, a roller 28 and linear guide bearings 4, 4 '. The HB and the resistance valves WA and WB are opened and closed in a predetermined order. Further, the wavy motion suppression device 40 is provided in the portion that becomes the empty phase. That is, a cam 41 having a flat surface facing the rolling member is provided on the drive shaft 26, a ball 42 is brought into contact with the flat surface of the cam 41 as a rolling member, and a flat plate of the cam 41 is applied by a load of the compression spring 43. The ball 42 is pressed on the top.
The compression spring 43 is attached to the spring attachment fitting 44.
Reference numeral 45 is a mounting base fixed to the bearing plate 5.

By the way, the groove 41a of the cam 41 is a groove for opening and closing the vacuum valves HA, HB, WA, WB in a predetermined order as shown in FIG. Is wider than the groove 41a, and in this way, in the wavy motion suppressing device 40 of the present invention, the balls 42 are brought into contact with the upper and lower surfaces of the flat plate of the cam 41 in the vertical direction and pressed by the compression spring 43. , The wavy movement of the cam 41 is suppressed.

As described above, according to this embodiment, the cam wave motion suppressing device 40 is directly attached to the empty phase portion of the three-phase device instead of the main valves HA and HB and the resistance valves WA and WB.
Even if it is a single-phase device or a single-phase device, smooth rotational motion can be obtained as in the case of a three-phase device, and the wavy motion suppressing device 40 can be attached as it is, so that it can be manufactured at low cost. Furthermore, the three-phase device can be partially modified to produce a two-phase device and a single-phase device, which is extremely advantageous in production.

FIG. 4 and FIG. 5 are a plan view and a developed view of a switching switch for a load tap changer using the wavy motion suppressing device.

FIG. 4 (a) shows a conventional switching switch for comparison 3
It is a top view of a phaser. Vacuum valves HA, HB are U, V, W respectively
Since they are in phase, the opening and closing operations are performed in a predetermined order by the rotational movement of the cam 27 arranged at the center. FIGS. 4 (b) and 4 (c) are plan views of a two-phase device and a single-phase device in which the wavy motion suppressing device 40 of the present invention is attached to the empty phase portion, respectively. In these figures, the groove 41a of the cam 41 arranged at the center is shown.
The vacuum valves HA and HB are opened and closed in a predetermined order.However, since the wavy motion suppressing device 40 is attached to the empty phase portion, the wavy motion of the cam is not caused by the rotary motion of the switching device. Absent.

5 (a), (b) and (c) are boundary lines between the U and W phases corresponding to FIGS. 4 (a), (b) and (c), respectively.
It is a development view developed at 60 °.

FIG. 5 (a) is a case of the conventional example, and is a development view of a three-phase device corresponding to FIG. 4 (a), in which vacuum valves HA, HB are provided for U, V, W phases, respectively. The cam 27 has two grooves 27a.
Is provided to open and close the vacuum valves HA and HB in a predetermined order.

Fig. 5 (b) is a development view of the two-phase device corresponding to Fig. 4 (b), in which two grooves 41a of the cam 41 are provided in the two phases U and V,
As described above, the vacuum valves HA and HB are opened and closed in a predetermined order, but the wavy motion suppression device 40 is installed in the empty phase portion of the W phase. That is, the single groove 41b is provided, and the balls 42 are pressed by the springs 43 on the upper and lower side surfaces of the flat plate of the cam 41, respectively.

Further, FIG. 5 (c) is a development view of the single-phase device corresponding to FIG. 4 (c), in which the balls 42 are respectively springed on the upper and lower surfaces of the flat plate of the cam 41 in the empty phase portion of the two phases V and W. The structure is the same as that shown in FIG.

In this embodiment, as described above, in the two-phase device or the single-phase device, the wavy motion suppressing device is arranged in the empty phase portion so that the unbalanced load acting when the vacuum valve is opened and closed can be countered. Since it is configured, a stable switching operation similar to that of a three-phase device can be obtained.

FIG. 2 is a vertical sectional view of another embodiment of the present invention. This embodiment is different from the embodiment shown in FIG. 1 only in the structure of the wavy motion suppressing device 53. That is, the wavy motion suppressing device 53
Of the cam 46, the empty phase portion of the cam 46 is formed in a flat plate shape, and cam followers 47 as rolling members are arranged above and below the flat phase portion, and the cam follower 47 is connected to the spring mounting bracket 49 via a shaft 50. A tension spring 48 is provided in the spring mounting member 49, and the wavy movement of the cam 44 is suppressed by the load of the tension spring 48. 45
Is a mount, 51 is a rail, and 52 is a bearing. The plan view and the developed view are the same as those in FIGS. 4 and 5, and therefore the description thereof is omitted.

FIG. 3 is a vertical sectional view of still another embodiment of the present invention.
This embodiment and the embodiment shown in FIG. 1 are the wavy motion suppressing device 60.
The only difference is the configuration. That is, in the wavy motion suppressing device 60, the empty phase portion of the cam 54 is formed into a flat plate, a single groove 55 is provided on the outer peripheral portion of the cam 54, and the balls 56 as rolling members are provided on the upper and lower surfaces of the groove 55. The compression spring 57 is arranged to suppress the wavy movement of the cam 54. 5 is a bearing plate, 58 is a spring fitting, and 59 is a mount.

6 (a) and 6 (b) correspond to FIG. 3, respectively.
FIG. 3 is a development view of a two-phase device and a single-phase device expanded 360 ° at the boundary line between the U and W phases.

In FIG. 6 (a), the two grooves 54a of the cam 54 are provided in the two phases U and V to open and close the vacuum valves HA and HB in a predetermined order, but the W-phase empty phase part is wavy. A motion suppression device 60 is installed. That is, a single groove 55 is provided, and balls 56 are arranged as rolling members on the upper and lower surfaces of the groove 55, and the wavy movement of the cam 54 is suppressed by the load of one compression spring 57.

Further, FIG. 6 (b) has the same configuration as that of FIG. 6 (a) except that the wavy motion suppressing device 51 is provided in the two-phase empty phase portions of V and W.

In the above embodiment, the tap change transformer under load having a triangular connection has been described, but the present invention is not limited to this, and the tap change transformer under load having a star winding or V connection in which the tap winding is provided on the high voltage side. It is clear that it can also be applied to.

[Effects of the Invention] As described above, according to the tap change transformer during load of the present invention, since the wavy motion suppression control device is arranged in the empty phase portion of the vacuum valve, a two-phase device at the time of tap change, The effect that a smooth rotary motion can be obtained in any of the single-phase devices is achieved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention, FIG. 2 is a vertical sectional view of another embodiment of the present invention, and FIG. 3 is a vertical sectional view of yet another embodiment of the present invention. FIGS. 5 (a) and 4 (b) and (c) are plan views of a conventional switching switch and a two-phase device and a single-phase device in which the wavy motion suppressing device of the present invention is attached to an empty phase part, respectively. Figures (a), (b), and (c) are development views expanded 360 ° at the boundary line between the U and W phases corresponding to Figures 4 (a), (b), and (c), respectively, and Figure 6 ( (a) and (b) correspond to FIG. 3 (a) and (b), respectively.
A development view of a two-phase device and a single-phase device expanded 360 ° at the boundary line between the U and W phases. Fig. 7 is a vertical cross-sectional view of a conventional three-phase switching switch.
FIG. 8 is a detailed view of the linear guide bearing portion of FIG. 7, where FIG. 8 (a) is a plan view, FIG. 8 (b) is a vertical cross-sectional view, and FIG. FIG. 10 is a three-phase circuit diagram using two conventional load tap changers. 5 …… Bearing plate 23 …… Storing device 26 …… Drive shaft 27,41,46,54 …… Cam 40 , 53,60 …… Wavy motion suppression device 42,56 …… Ball 43,59 …… Compression spring 44,49 …… Spring mounting bracket 45,58 …… Mounting base 47 …… Cam follower 48 …… Tension spring 50 …… Axis 51 …… Rail 52 …… Bearing 55 …… Groove

Claims (1)

[Claims] 1. A switching switch for a vacuum valve load tap changer, wherein a plurality of vacuum valves are arranged on a plane, and three phases are simultaneously switched by a groove cam provided at the center of the switch. When configuring a phase or single-phase device 3
In the vacuum valve portion of the empty phase of the phase structure, a wavy motion suppressing device including a rolling member in contact with the outer peripheral portion of the groove cam and a spring type shock absorber for pressing the rolling member against the outer peripheral portion of the groove cam is arranged. A switching switch for vacuum valve type tap changer under load.