CN85202098U - Longitudinal magnetic field contact for vocuum circuit breaker - Google Patents

Abstract

The utility model provides a new longitudinal magnetic field contact. The back side of a main contact is provided with a coil electrode, and the middle part of the coil electrode is provided with two conducting columns. Two to four arc coils are collocated on periphery, and the two ends of every arc coil are respectively connected with two conducting columns. The upper surface of one conducting column and the back side of the main contact are connected, and the other conducting column is connected with a conducting rod. When the longitudinal magnetic field contact breaks current, the size and the distribution of the longitudinal magnetic field generated in the clearance of the contact do not change with the distribution of vacuum arcs on the surface of the contact, and therefore, the utility model has large and stable current breaking ability.

Description

Longitudinal magnetic field contact for vocuum circuit breaker

Vertical magnetic field of the present invention contact belongs to the parts of vacuum circuit-breaker in the High-Voltage Electrical Appliances.

The structure of existing vertical magnetic field contact (as US Patent specification 3946179) is shown in Fig. 1 to Fig. 4, wherein, Fig. 1 is the vertical view of vertical magnetic field contact, and Fig. 2 is the end view of Fig. 1, Fig. 3 is the A-A cutaway view of Fig. 1, and Fig. 4 is the B-B cutaway view of Fig. 2.The main points that should indulge the magnetic field contact are: in the back side of contact (a 1) configuration coil electrode (2) (see figure 2).There is a conductive pole (21) (seeing Fig. 3 and Fig. 4) in the central authorities of coil electrode (2).The one side of the contact dorsad (1) of conductive pole (21) links to each other with conducting rod (3).The peripheral part of coil electrode (2) is four arc coils (22).One end of each arc coil (22) links to each other with the cylinder of conductive pole (21) by radial conductor (23), and the other end links to each other with contact (1) by conductor (24).The structure of dynamic and static contact is identical.In order to reduce eddy current, on contact (1), have some radial slots (11) (Fig. 1).

The electric current that flows through vacuum circuit-breaker is through conducting rod (3), behind the conductive pole (21), be divided into four the tunnel and flow through four by radial conductor (23), the parallel branch that arc coil (22) and conductor (24) are formed enters contact (1).When vacuum electric arc evenly distributed on contact (1) or is positioned at the center of contact (1), four parallel branches were equal to the impedance of electric current, and the electric current that flows through each parallel branch also equates.When this electric current flows through in four arc coils (22), produce a uniform unipolar longitudinal magnetic field between contact (1), this magnetic field makes above-mentioned vertical magnetic field contact have the ability of big drop-out current.

The shortcoming of above-mentioned vertical magnetic field contact is: vacuum arc is at contact (1) when surface distributed is inhomogeneous, and is just unequal by the electric current of each arc coil (22).For example, when (16) that vacuum electric arc is positioned at Fig. 1 when locating, the electric current of four parallel branches will pass through (12)-(16) respectively, (13)-(16), and between (15)-(16) path shown in the double dot dash line (14)-(16), their length difference, also unequal to the impedance of electric current.These four mutual unequal impedances are connected on respectively in four parallel branches, make the electric current that flows through each arc coil (22) no longer equal.Cause the longitudinal magnetic field skewness between contact thus, the longitudinal magnetic field skewness reduces the current breaking capacity of vertical magnetic field contact, because the position of arcing point is unsettled, thereby the distribution of starting the arc moment vacuum arc on contact (1) is change at random.This just makes the electric current breaking capacity instability of above-mentioned vertical magnetic field contact.The longitudinal magnetic field skewness can make vacuum arc some regional centralized to contact (1), and this makes above-mentioned vertical magnetic field contact surface local serious scaling loss occur, thereby electric life is shortened.

The present invention is the vertical magnetic field contact that a kind of vacuum circuit-breaker of making in order to overcome above-mentioned shortcoming is used, it is in the process of drop-out current, produce the unipolarity longitudinal magnetic field in the contact gap, the size and the distribution thereof of this longitudinal magnetic field do not change with the variation of vacuum arc in the distribution of contact surface.

The structure of vertical magnetic field of the present invention contact is shown in Fig. 5 to Fig. 8.Wherein, Fig. 5 is the vertical view of the vertical magnetic field contact of invention, and Fig. 6 is the end view of Fig. 5, and Fig. 7 is a C-C cutaway view on Fig. 5, and Fig. 8 is the D-D cutaway view on Fig. 6.

Main points of the present invention are: the front (41) of main contact (4) is the arcing surface.The back side (42) of main contact (4) is provided with the coil electrode made from oxygen-free copper (5) (seeing Fig. 6 and Fig. 7).There are two conductive poles (51) and (52) (seeing Fig. 7 and Fig. 8) in the middle part of coil electrode (5), and several arc coils (54) are arranged on the periphery.Arc coil (54) number is 2 to 4, and arc coil (54) number is determined (having drawn 4 arc coils (54) in Fig. 8) by required magnetic field.Arc coil (54) is arranged on week in the garden end to endly, forms a garden ring that has groove (57) to separate, this garden ring and conductive pole (51) and (52) concentric arrangement.Connect with radial conductor (55) between the cylinder of one end of each arc coil (54) and conductive pole (51), connect with radial conductor (56) between the cylinder of the other end and conductive pole (52).The number of the number of radial conductor (51) and radial conductor (52) is identical with arc coil (54) number.Link to each other with conductor (53) between the back side (42) of the upper surface of conductive pole (51) and main contact (4).Conductive pole (52) links to each other with conducting rod (7) away from an end of main contact (4).Be placed with between conductive pole (51) and the conductive pole (52) with alumina content and be higher than the insulating trip (6) that 70% high-alumina ceramic is made.The above-mentioned vertical magnetic field of a pair of identical in structure contact disposes relatively, can make the dynamic and static contact of vacuum circuit-breaker.

Be the action principle that example illustrates the vertical magnetic field of the present invention contact with the vertical magnetic field contact of being invented below with 4 arc coils (54).When indulging the magnetic field contact closure, the front (41) of main contact (4) is in contact with one another, electric current is through conducting rod (7), conductive pole (52), be divided into four the tunnel then and pass through radial conductor (56) successively, arc coil (54) and radial conductor (55) arrive conductive pole (51), pass through conductor (53) again and flow into main contact (4).By radial conductor (56), the impedance of four parallel branches that arc coil (54) and radial conductor (55) are formed equates, the electric current that flows through 4 arc coils (54) is identical, and direction is also identical, and they form a complete circulation.Current direction in the arc coil (54) on the dynamic and static contact is identical.These two circulation produce the longitudinal magnetic field of required single polarity between contact.Because by radial conductor (56), the two ends of four parallel branches that arc coil (54) and radial conductor (55) are formed do not comprise the conductor resistance of main contact (1) by conductive pole (52) and conductive pole (53) short circuit in the parallel branch.So the impedance of four parallel branches does not change because of the change of the distribution of vacuum arc on main contact (1), electric current in the arc coil (54) does not change with the change of the distribution of vacuum arc on main contact (1) yet, this is not subjected to the influence of the distribution of vacuum arc on main contact (1) with regard to the longitudinal magnetic field that the vertical magnetic field contact that guarantees to be invented is produced, thereby has stable current breaking capacity.

Compare with existing vertical magnetic field contact, vertical magnetic field of the present invention contact has following advantage: 1, have stable current breaking capacity; 2, uniformly longitudinal magnetic field is impelled Vacuum Arc uniform to be distributed to whole arcing surface to get on.Thereby has a big current breaking capacity; 3, the surperficial scaling loss of main contact (1) is even, and electric life is long.

Claims (4)

1 one kinds of vacuum circuit-breakers of being made up of main contact and coil electrode are with indulging the magnetic field contact, the back side that it is characterized in that main contact (4) is provided with coil electrode (5), there are two conductive poles (51) and (52) in the middle part of coil electrode (5), dispose arc coil (54) on the periphery, connect with radial conductor (55) between the cylinder of one end of each arc coil (54) and conductive pole (51), connect with radial conductor (56) between the cylinder of the other end and conductive pole (52).Connect with conductor (53) between the back side (42) of the upper surface of conductive pole (51) and main contact (4).Be placed with insulating trip (6) between conductive pole (51) and (52).Conductive pole (52) links to each other with conducting rod (7) away from an end of main contact (4).

2 according to the described vertical magnetic field of claim 1 contact, it is characterized in that coil electrode (5) upward configuration 2 to 4 arc coils (54) and same number of radial conductor (55) and (56).

3 according to the described vertical magnetic field of claim 1 contact, it is characterized in that coil electrode (5) makes with oxygen-free copper.

4 according to the described vertical magnetic field of claim 1 contact, it is characterized in that insulating trip (6) with salic amount greater than 70% high-alumina ceramic manufacturing.

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