JP2004349117A - Quadrupole operating mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quadrupole operating mechanism in a 3-phase 4-wire power distribution system, that causes a N-phase contact to close before other 3-phase contacts have closed, and causes it to open after they have opened in order to prevent the occurrence of abnormal voltage due to the deviation of a neutral point. <P>SOLUTION: In a quadrupole operating mechanism for a switchgear having quadrupole contacts that opens, closes a circuit containing 3-phase lines and a neutral line, the mechanism includes a contact pressure spring assembly that causes only a contact of the neutral line to close earlier and to open later than the contacts of other poles. The contact pressure spring assembly includes a wipe link coupled to a main shaft and displaces relatively to a contact, a wipe link rod coupled slidably in axial direction to the wipe link at one end, coupled to a movable rod at the other end, and a contact pressure spring that exerts contact pressure between fixed and movable contacts when a contact is closed. For the length of the wipe link rods, the rod in a pole of the neutral line is designed to be longer than the rods in other poles. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an operation mechanism of a switch such as a circuit breaker.
[0002]
[Prior art]
The need to boost the distribution voltage has been increasing due to new income difficulties at substation sites and increased power demand. For this reason, it has been proposed to introduce an 11.4 kV overhead distribution system, which adds one neutral wire to the existing 6.6 kV distribution line and increases the distribution capacity by a factor of 3 times. Is required. However, there has been no suitable operation mechanism for a switch such as a four-pole circuit breaker in such a three-phase four-wire power distribution system. For example, a zero-phase current transformer is provided. A neutral pole is provided on the opposite side of the pole where the switching mechanism is placed across the pole, and the primary conductor of the neutral pole penetrates the zero-phase current transformer, enabling detection of four-pole leakage unbalanced current. The following has been proposed (for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-8-185787
[Problems to be solved by the invention]
However, such conventional circuit breakers are merely four-pole switches. In addition, a neutral wire is added to the conventional three-phase three-wire 6.6 kV distribution line to make the line voltage √3 times 11.4 kV. If the points deviate, abnormal voltage will be generated when the circuit breaker is opened and closed.
[0005]
For this reason, when closing the circuit breaker, the neutral phase N-phase is connected before the three phases A, B, and C are connected by the circuit breaker. After the phases B, C and C have been interrupted, the neutral N-phase must be cut off.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to provide a four-pole operating mechanism capable of shifting the operation timing of the neutral conductor from other phases by simple means.
[0007]
[Means for Solving the Problems]
According to the present invention, a four-pole operating mechanism for a switching device having four-pole contacts for opening and closing a circuit including a three-phase wire and a neutral wire is provided with a drive source; A movable main shaft connected to a drive source and common to the contacts, one end connected to the main shaft, and the other end connected to a movable rod of each of the contacts to provide a wipe distance to the contacts, A contact pressure spring assembly that closes the contact earlier than other poles and opens later later by only the pole of the neutral wire when is driven.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
The four-pole operating mechanism of the present invention is configured as shown in FIGS. 1 and 2 and is configured to connect a neutral line N-phase line 1 and three-phase A-phase line 2, B-phase line 3 and C-phase line 4 to each other. This is an operation mechanism for a switchgear provided with four-pole contacts 5, 6, 7, and 8 for opening and closing a three-phase four-wire power distribution circuit. Such contacts 5 to 8 are provided, for example, in a vacuum vessel 10 of a vacuum valve 9 as shown in the figure, and are connected to a power distribution circuit and can be separated from and connected to. The contacts 5 to 8 are respectively connected to a fixed contact 12 fixed to the inner end of a fixed rod 11 fixed through the vacuum vessel 10 and an inner end of a movable rod 13 movably extended through the vacuum vessel 10. And a fixed movable contact 14.
[0009]
The four-pole operating mechanism according to the present invention includes a drive source 15 which is an operation drive device which may be a known device per se, and a drive source 15 connected to the drive source 15 via a lever 16 to form four contact points of four vacuum valves 9. A common main shaft 18 rotatable with respect to 5 to 8 is provided. The main shaft 18 is connected to the opening spring 17. The four-pole operating mechanism also includes a wipe link 21 having a U-shaped cross section that is pivotally supported by a pin 20 on a pair of levers 19 protruding from the main shaft 18 corresponding to the contacts 5 to 8. The U-shaped central portion of the wipe link 21 has one end loosely slidable in the axial direction and the other end firmly connected to the movable rod 13 of the contacts 5 to 8 by screw engagement. Is connected. A flange 23 is provided on the wipe link rod 22, and a contact pressure spring 24, which is a compression spring, is provided coaxially with the wipe link rod 22 between the flange 23 and a U-shaped central portion of the wipe link 21. Have been.
[0010]
As described above, the wipe link 21, the wipe link rod 22, and the contact pressure spring 24 are connected at one end to the main shaft 18, and connected at the other end to the movable rods 13 of the respective contacts 5 to 8, and contact the contacts 5 to 8. The contact pressure spring assembly 25 that provides a wipe distance (wipe amount) together with the pressure is configured. The structure and dimensions of each phase including the N phase of the neutral wire are the same as each other except for the length of the wipe link rod 22, and the length of the wipe link rod 22 of the N phase pole is the same as that of the other phase. The length of the wipe link rods 22 of the other phases is the same as each other. For this reason, as shown in FIG. 1, the separation distance Dn of the contacts of the N-phase pole of the neutral wire is smaller than the opening distances Da, Db and Dc of the other A-phase, B-phase and C-phase contacts. As shown in FIG. 5, the wipe distance Wn of the N-phase contact of the neutral wire is made larger than the wipe distance W of the other phase, so that the final contact pressure load is the same as that of the other phase.
[0011]
The wipe link 21 is connected to the main shaft 18 via a pair of levers 19. When the main shaft 18 rotates, the wipe link 21 moves closer to or farther from the contacts 5 to 8 together with the pins 20 on the lever pair 19. It relatively displaces, and operates from the opening position to the closing position according to the position. In the opening position shown in FIGS. 1 and 2, the pin 20 provided on the lever pair 19 on the main shaft 18 is located above the center 26 of the main shaft 18 in the drawing, and the wipe link 21 raises the wipe link rod 22. In position. The positions of the pin 20 and the wipe link 21 are the same for all four phases.
[0012]
As described above, the length of the wipe link rod 22 is longer in the N-phase than in the other A-phase, B-phase and C-phase, and the length of the movable rod 13 is the same. Even if the position of the wipe link 21 is the same in each phase, the lower end of the wipe link rod 22, that is, the position of the movable rod 13, that is, the position of the movable contact 14 is only slightly lower than that of the other phases. In addition, the opening distance Dn of the contact 5 is smaller than the opening distances Da, Db, and Dc of the other contacts 6 to 8.
[0013]
In such a four-pole operating mechanism, the total breaker stroke is the sum of the opening distance dimension D and the wipe dimension W. The opening distance dimension is a distance from the breaker “open” position to the contact touch position. The wipe size is a pushing amount for applying a contact pressure load necessary for a contact from a contact touch position by a contact pressure spring or the like. Generally, a wipe link mechanism is used for the pushing, and after the contact is touched, the contact pressure spring bends to generate a contact pressure load.
[0014]
When the circuit breaker is closed, when closing from the open position, the driving force from the drive source 15 is transmitted to the main shaft 18 via the lever 16, and the main shaft 18 is opposed to the opening spring 17. 2 rotates counterclockwise. Due to the rotation of the main shaft 18, all of the four-phase lever pairs 19 push down the wipe link 21 through the pins 20 in the figure, and the movable rod 13 and the wipe link rod 22 are moved together with the wipe link rod 22 by the contact pressure spring 24 in each phase. The movable contact 14 is pushed down toward the closing position. At this time, there is no relative movement between the wipe link 21 and the wipe link rod 22.
[0015]
When the movable contact 14 moves toward the closing position in this manner, first, as shown in FIG. 3, the N-phase movable contact 14 having the smallest (Dn) contact separation distance becomes the fixed contact 12. Contact At this time, the contacts 6 to 8 of the A phase, the B phase and the C phase are still in a slightly opened state.
[0016]
As the rotation of the main shaft 18 further advances due to the driving force, the N-phase contact pressure spring 24 starts to be compressed, and a contact pressure is generated. Eventually, the remaining three phases, that is, the A-phase, B-phase and C-phase contact points 6 to 8 are in contact with each other, and the contact state is established in all four phases as shown in FIG. After the contact is touched, the movable rod 13 of the vacuum valve and the wipe link rod 22 do not move, and the wipe link 21 is further depressed, so that the contact pressure spring 24 is compressed, the contact pressure of the contact 5 increases, and the contact 6 A contact pressure load is generated at ~ 8. The N-phase wipe link rod 22 is longer than the A-phase, B-phase, and C-phase wipe link rods 22, and the distance between the N-phase contacts, that is, the opening distance Dn, is smaller than the other phases Da, Db, and Dc. Assuming that the opening distance Dn of the N phase is a distance required for the circuit breaker, it can be said that the opening distances Da, Db and Dc of the A phase, B phase and C phase are larger than the separation distance Dn of the N phase.
[0017]
The circuit breaker opening operation is substantially the reverse of the above-described closing operation. The operating mechanism is released by a known latch or the like, and the main shaft 18 is rotated clockwise in FIG. The bending of the pressure spring 24 is released. First, the wipe distances of the phases A, B, and C become zero at the position shown in FIG. 4, and then the state shown in FIG. 3 is established, and the contacts 6 to 8 of the phases A, B, and C are opened. At the position shown in FIG. 4, the N-phase wipe distance has not yet become zero, and the contact pressure spring 24 is still bent. Thereafter, the N-phase wipe distance becomes zero at the position shown in FIG. 3, and the N-phase contact 5 is opened after the contacts 6-8 of the A-phase, B-phase and C-phase are opened, and the breaker shown in FIG. It becomes the extreme position, and the operation is completed by being held at this position by the opening spring 8 or the like.
[0018]
This stroke relationship is shown in FIG. First, the stroke in the circuit breaker will be described. The total breaker stroke is the sum of the opening distance dimension and the wipe dimension. The opening distance dimension is a distance from the breaker “open” position to the contact touch position. The wipe size is a pushing amount for applying a necessary contact pressure load to a contact from a contact touch position by a spring or the like. Generally, a wipe link mechanism is used for the pushing, and after the contact is touched, the contact pressure spring bends to generate a contact pressure load.
[0019]
Thus, according to the four-pole operation device of the present invention, the N-phase contact touch timing is earlier than the other phases in the circuit breaker closing operation, and the N-phase contact opening timing is different from the other phases in the circuit breaker opening operation. It can be slowed down, does not require a new mechanism, can be configured with one operation mechanism, and has a small number of parts.
[0020]
Even if the N-phase opening distance is the distance required for the breaker and the wipe distance is longer than the other phases, the final contact pressure load should be the same as the other phases by changing the length of the wipe link rod. Can be. In A-phase, B-phase and C-phase, by increasing the opening distance of the circuit breaker, the required operating energy of the circuit breaker increases, but the increase in the required load only by increasing the stroke to open the contacts. Since there is no energy increase, the energy increase is relatively small in view of the total energy of the circuit breaker, and it is only necessary to previously set the operation energy as large as necessary.
[0021]
【The invention's effect】
According to the present invention, a four-pole operation mechanism for a switchgear having four-pole contacts for opening and closing a circuit including a three-phase wire and a neutral wire is provided with a drive source and a drive source connected to the drive source. In contrast, a common movable main shaft and one end are connected to the main shaft, and the other end is connected to a movable rod of each of the contacts to provide a wipe distance to the contacts, and the neutral wire is driven when the main shaft is driven. And a contact pressure spring assembly for closing the contact earlier than the other poles and opening the contact later than the other poles. Therefore, in the circuit breaker closing operation, the N-phase contact touch timing can be earlier than the other phases, and in the circuit breaker opening operation, the N-phase contact opening timing can be later than the other phases.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing an opening position of a four-pole operating mechanism of the present invention.
FIG. 2 is a schematic side view of the four-pole operating mechanism shown in FIG.
FIG. 3 is a schematic front view showing a state in which an N-phase contact of the four-pole operating mechanism of FIG. 1 is in contact.
FIG. 4 is a schematic front view showing a state where A to C phase contacts of the four-pole operating mechanism of FIG. 1 are in contact with each other;
FIG. 5 is a schematic front view showing an input position of the four-pole operating mechanism of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Neutral wire, 2, 3, 4 Three-phase wire, 5, 6, 7, 8 contacts, 12 fixed contacts, 13 movable rods, 14 movable contacts, 15 drive source, 18 spindle, 21 wipe link, 22 wipe link rod , 24 contact pressure spring, 25 contact pressure spring assembly, Da, Db, Dc, Dn separation distance, Wn, W wipe distance.

Claims (4)

A four-pole operating mechanism for a switchgear having four-pole contacts for opening and closing a circuit including a three-phase wire and a neutral wire,
A drive source, a movable main shaft connected to the drive source and common to the contacts, and one end connected to the main shaft and the other end connected to a movable rod of each of the contacts to wipe the contact; And a contact pressure spring assembly for closing the contact point earlier than the other poles by the pole of the neutral wire and opening it later later when the main shaft is driven. Polar operation mechanism. Each of the contact pressure spring assemblies is
A wipe link connected to the main shaft and relatively displaced with respect to the contact point;
A wipe link rod connected at one end to the wipe link so as to be slidable in the axial direction, and the other end connected to the movable rod;
A contact pressure spring that is provided between the wipe link and the movable rod and that applies a contact pressure between the contacts when the contacts are closed;
2. The four-pole operating mechanism according to claim 1, wherein the length of the wipe link rod is longer at a pole of the neutral wire than at other poles. The four-pole operating mechanism according to claim 1 or 2, wherein a separation distance of the contacts of the neutral poles is smaller than an opening distance of the three-pole contacts. 4. The method according to claim 1, wherein the wipe distance of the contact point of the neutral wire is greater than the wipe distance of the other poles, so that the final contact pressure load is the same as that of the other phase. A four-pole operating mechanism according to any one of the preceding claims.

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