JPS6253887B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas disconnector, particularly a magnetically driven gas disconnector, and its purpose is to effectively drive an arc even in a small current disconnection area and provide sufficient disconnection and disconnection performance. The purpose of the present invention is to provide a device of this kind having the following characteristics.

As is well known, magnetically driven type gas shields and disconnectors are so-called self-extinguishing types that use the generated magnetic flux to rotate and extinguish the arc by commutating the disconnection current through a drive coil installed at the edge or at the disconnection point. It's a noshiya disconnection. Therefore, in a small current range, the generated magnetic flux is reduced, the rotational driving force is weakened, and the arc time becomes longer.

This will be explained based on the conventional device shown in FIG. In this figure, the arc generated between the fixed contact 1 and the movable contact 2 is commutated to the arc runner 3, and the drive coil 4 wound between the arc runner 3 and the fixed contact base 5 is cut. The arc is extinguished by rotationally driving the arc using magnetic flux _φ1 generated by flowing current. Note that 6 is an insulating sleeve that insulates between the drive coil 4 and the fixed contact 1, and the whole is housed in a container filled with an insulating arc-extinguishing gas such as SF ₆ gas, but for the sake of simplicity, Not shown.

In the above configuration, in order to obtain sufficient rotational driving force in a small current range, it is sufficient to increase the number of turns of the drive coil 4, but this increases the size of the coil portion. In addition, if the number of turns of the drive coil 4 is increased, a large current will be generated, and the drive coil 4 itself, the drive coil 4 and the arc runner 3
A strong electromagnetic repulsive force is generated between the drive coil 4 and the fixed contact base 5, and it is extremely difficult to obtain a strong device that can resist this electromagnetic repulsive force.

The present invention has been proposed in view of the above points, and will be explained below based on FIGS. 2 to 4.

Figure 2 is a longitudinal cross-sectional view of one embodiment of the gas shield disconnector of the present invention, showing the state in the middle of disconnection, and Figure 3 is a diagram illustrating the generated magnetic flux, a longitudinal cross-section showing the middle of the disconnection. Top view, b is a diagram explaining the vicinity of the arc runner,
c is a diagram showing another embodiment of the arc runner, d
is a vector diagram showing the relationship between current and magnetic flux.
FIG. 4 is a diagram showing still another embodiment of the arc runner.

In the figure, 1 is a hollow fixed contact, and 2 is a movable contact that approaches and separates on the inner peripheral surface of the fixed contact 1. 3 is an arc runner, 4 is a drive coil with a very small number of turns compared to conventional ones, 5 is a fixed contact base, 6 is an insulating sleeve, and 7 is a magnetic metal cylinder. A fixed contact 1 is provided in the center, and a magnetic metal cylinder 7 and an insulating sleeve 6 are arranged on the outside of the fixed contact 1.
The drive coil 4 has one end electrically connected to the arc runner 3 and the other end electrically connected to the fixed contact base 5, and these are attached to the fixed contact base 5. (Electrical connection and mounting methods are not shown). The inner diameter d ₂ of the magnetic metal cylinder 7 is the inner diameter of the arc runner 3.
d is larger than ₁ , and both are arranged coaxially as shown in the figure.

The entire structure is housed in a container filled with an insulating arc-extinguishing gas such as SF ₆ gas, but this is not shown for the sake of brevity.

Now, when the movable contact 2 is pulled down by an operating device (not shown), the movable contact 2 and the fixed contact 1 are separated, and an arc is generated between them. Since the number of turns of the drive coil 4 is extremely small, this arc easily moves between the arc runner 3 and the movable contact 2 and becomes an arc 8. As a result, a short current is commutated to the drive coil 4, and a primary magnetic flux _φ1 is generated by the drive coil 4.

This primary magnetic flux φ ₁ is the inner diameter of the arc runner 3
Since the structure is such that d ₁ and the inner diameter d ₂ of the magnetic metal cylinder 7 satisfy d ₁ <d ₂ , the magnetic flux φ _1a that passes through the inner diameter portion of the arc runner 3 and the magnetic flux φ 1a that passes through the magnetic metal cylinder 7 and the arc runner 3 The magnetic flux _φ1b passing through the plate surface (the shaded area in FIG. 3b) is roughly divided into two types.

As shown in FIG. 3b, when the arc runner 3 has no interruption and forms a shot ring, a current i _2a is induced in the arc runner 3 by the magnetic flux φ _1a penetrating the inner diameter part, and this causes a secondary magnetic flux φ _2a occurs in the direction of the dotted arrow in the figure. Also, due to the magnetic flux φ _1b penetrating the plate surface of the arc runner 3, the arc runner 3
The following two currents flow through.

That is, a current i _2b is induced inside the cylinder 7 of the arc runner 3 in the direction of the dotted arrow in the figure, thereby generating a secondary magnetic flux φ _2b . Further, a current i _2b ' opposite to the current i _2b is induced outside the cylinder 7 in the direction of the dotted arrow.

Therefore, of the composite of the magnetic flux φ _2b and the magnetic flux φ _2a , the component perpendicular to the arc 8 is the arc 8.
is rotated by the inner diameter portion of the arc runner 3.

It is a well-known fact that in the case where the arc is extinguished by applying a rotational driving force to the arc using a magnetic flux perpendicular to the arc, the rotational speed of the arc immediately before the current zero point greatly affects the cutting performance. Particularly in the small current break region where the rotational driving force is weak, it is effective to moderate the phase of the arc current and magnetic flux in order to strengthen the rotational driving force just before the current zero point. By forming this, a phase difference can be provided.

The relationship between the current and magnetic flux is shown in a vector diagram as follows:
It will look like Figure 3d.

To explain again based on this, the magnetic flux _{φ 1} created by the arc current (current flowing through the drive coil 4) i has a component φ 1a that penetrates the inner space of the arc runner 3 and a component φ _1a that penetrates the plate surface of the arc runner 3. It is divided into components φ _1b .

A secondary current i _2a determined by the power factor and impedance of the arc runner ₃ , which is a circuit interlinked with the magnetic flux φ 1a, flows through the arc runner 3, thereby generating a magnetic flux φ _2a .

In addition, for the magnetic flux φ _1b penetrating the arc runner 3, a closed circuit is formed in which the outside and inside of the arc runner 3 are interlinked, and the direction is directed to the inner and outer circumferential sides depending on the impedance and power factor of this circuit. opposite current i
_2b and i _2b ′ flow, generating magnetic fluxes φ _2b and φ _2b ′, respectively. The magnetic flux φ _2b rotates the arc together with the magnetic flux φ _1a .

The magnetic flux φ _2b ' does not intersect the arc and therefore does not contribute to the rotational drive of the arc.

Note that θ ₁ and θ ₂ are phase angles determined by the power factor of the arc runner 3.

In the above configuration, a hollow fixed contact 1 and a movable contact 2 that comes into contact with and separates from the inner surface of the hollow fixed contact 1 are provided, and the fixed contact 1
A magnetic metal cylinder 7 is placed outside the magnetic metal cylinder 7, and a drive coil 4 is placed further outside of the magnetic metal cylinder 7, and the arc runner 3 is placed at the tip of these, and the inner diameter d1 of the arc runner ₃ and the inner diameter _d2 of the magnetic metal cylinder are set to d1 _. By configuring so that < d ₂ , the secondary magnetic flux φ _2a which has a phase difference with the arc current and controls the arc rotation speed just before the current zero point,
It is possible to generate φ _2b and rotate the arc 8 in the inner diameter part of the arc runner 3 where the secondary magnetic flux density is highest, and the number of windings of the drive coil 4 is extremely small and the performance is stable even in a small current range. A gas shield and disconnector having the following characteristics can be obtained.

Fig. 3c shows another embodiment of the gas shield breaker of the present invention, in which the arc runner 3 is provided with an interruption 3-1 so that the magnetic flux φ passes through the inner diameter of the arc runner 3.
Current i _2a and secondary magnetic flux φ _2a due to _1a are not induced. However, since the current i _2b and the secondary magnetic flux φ _2b are induced by the primary magnetic flux φ _1b penetrating the plate surface, this causes a phase difference with the arc current just before the current zero point, causing an interruption in the arc runner 3. It has the same effect as the case without interruption, and has the advantage that the electromagnetic repulsion force when the large current is interrupted is reduced compared to the case without interruption.

It is also possible to set the cross-sectional area of the magnetic metal cylinder 7 appropriately so that the strength of the magnetic field is saturated in the large current range, so that the generated electromagnetic repulsion force can be made equivalent to that of an air-core coil.

Further, the arc runner 3 does not necessarily have to be formed into a disk shape, and may be formed of an inner ring 3-2 and an outer ring 3-3 connected in series as shown in FIG.

This configuration has the advantage that the outer ring 3-3 can be positioned above the outer side of the coil 4 and a large amount of interlinkage magnetic flux can be obtained.

Furthermore, as a modification of this, the width of the inner ring 3-2 may be slightly increased to form a disc shape.

As detailed above, according to the present invention, secondary magnetic flux is generated in the inner diameter portion of the arc runner, and this magnetic flux and the magnetic flux generated by the current flowing through the drive coil combine to drive the arc. It is possible to effectively drive the arc by providing a sufficient phase difference between the arc current and the magnetic flux even in the current range and the current breakage range, and it is possible to drive the arc effectively without making the device too powerful or large. It becomes possible to obtain a gas insulator and disconnector that has a good disconnection performance.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional device, Fig. 2 is a longitudinal sectional view showing one embodiment of the present invention, and Fig. 3 is a diagram for explaining the magnetic flux generated in the device shown in Fig. 2. b is a diagram explaining the vicinity of the arc runner, c is a diagram showing another embodiment of the arc runner, d is a vector diagram, and FIG. 4 is a diagram illustrating another embodiment of the arc runner. This shows that. 1... Fixed contact, 2... Movable contact, 3... Arc runner, 3-1... Interrupt, 3-2... Inner ring, 3-3
...Outer ring, 4...Drive coil, 7...Magnetic metal cylinder, 8
…Arc, φ, φ _1a ~ φ _2b …Magnetic flux.

Claims (1)

[Scope of Claims] 1. A fixed contact, a movable contact disposed so as to approach and separate from the fixed contact, a magnetic metal cylinder disposed outside the movable contact, and a magnetic metal cylinder arranged on the outside of the movable contact. In an arc-rotating type gas shield and breaker consisting of a drive coil disposed on the outside and an arc runner disposed below the drive coil and the magnetic metal cylinder, the inner diameter of the magnetic metal cylinder is the same as that of the arc runner. 1. A gas shield and breaker characterized in that the arc runner is configured to have a larger diameter than the inner diameter, and the arc is rotationally driven by the secondary magnetic flux of the inner diameter portion of the arc runner. 2. The gas shield breaker according to claim 1, characterized in that the magnetic metal cylinder is configured to be saturated in a large current shield area. 3. The gas shield or disconnector according to claim 1 or 2, characterized in that the arc runner is provided with an interruption. 4. The gas sheath disconnector according to claim 1 or 2, characterized in that the arc runner is constructed by connecting an inner ring and an outer ring in series.