High-voltage electrical contactor comprising four arc chambers

Abstract

The invention relates to a contactor (1) comprising two pairs (C1, C2) of adjacent arc chambers (2), arranged in a rectangle and each divided into two electric arc extinguishing areas (8). Within each pair, each arc chamber comprises: a movable terminal (4) provided with a first and a second movable contact (5a, 5b), a first fixed terminal (6a) provided with a first fixed contact (7a) located facing the first movable contact (5a), a second fixed terminal (6b) common to the two arc chambers (2) and provided with a second fixed contact (7b) located facing the second movable contact (5b), - two electric arc extinguishing devices (17) each located in an extinguishing area (8). The contactor further comprises an actuator (18) connected to the four movable terminals, actuation of the actuator causing the four movable terminals to move simultaneously between a closed state and an open state.

Description

High voltage electrical contactor comprising four breaking chambers TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of high-voltage direct current contactors with several poles and comprising electric arc extinguishing fin blocks allowing the electric arc to be divided into several arcs.

[0002] The present invention relates to a high voltage direct current contactor comprising four breaking chambers each divided into two electric arc extinguishing zones. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] High Voltage Direct Current (HVDC) is a power electronics technology used for the transmission of high voltage direct current electricity.

[0004] High voltage direct current (HVDC) contactors comprise two electrical contacts for establishing, supporting and interrupting an electrically conductive connection for direct currents with a voltage usually in the order of 270 to 3000 volts in the aeronautical or automotive fields. When the contacts separate, electric arcs appear, accompanied by high thermal stresses as well as difficulties in extinguishing the electrical connection. These electric arcs are usually extinguished by moving them by a magnetic field towards an arc extinguishing zone comprising blocks of arc extinguishing fins. Sectioning the arcs on a plurality of fins makes it possible to increase the arc voltage and thus extinguish it.

[0005] Among HVDC contactors, double-pole contactors are known where each pole simultaneously cuts off the positive terminal and the negative terminal of an electric current source. Such a contactor 1' is shown in Figures 1 to 3.

[0006] The contactor 1 ' of the prior art comprises two parallel and adjoining breaking chambers 2' to minimize the size. Each breaking chamber comprises a movable bridge 3' comprising a movable terminal 4' carrying two movable contacts 5' and two fixed terminals 6' each carrying a fixed contact 7' opposite a movable contact 5'. Each breaking chamber 2' is separated into two electric arc extinguishing zones 8' by separating partitions 9', each breaking chamber cut-off 2' comprising an electric arc extinguishing device 17'. Each extinguishing device 17' comprises at least one magnetic field emitting device 10' of constant direction, for example a magnet, generating a magnetic field M (the orientation of which is represented by a thick black arrow) and exerting a Laplace electromagnetic force F (the orientation of which is represented by a thick white arrow) on each electric arc 11' likely to form between two facing contacts so as to move it towards an electric arc extinguishing block 12' equipped with fins 13'. These movements can be guided by arc guides 14' each located between an extinguishing block 12' and a movable contact 5'. The two breaking chambers 2' are separated by a separating wall 15'. The contactor 1' is protected inside a housing 16'.The two movable bridges 3' are connected to each other by a bar 19' via an axis 20', said bar 19' being able to be moved by an actuator 18' so as to simultaneously move all the movable contacts 5' away from the fixed contacts 7' to cut the current or to bring them all into contact in pairs simultaneously to restore the current. The flow of the electric current / is represented by a dotted arrow.

[0007] The contactor 1' as shown in Figures 1 to 3 is suitable for currents with a voltage of up to 800 volts. For higher voltages, in particular of the order of 1600 volts, it is necessary to increase the number of fins 13' and the working stroke length of the actuator 18', which results in a significant increase in the overall dimensions of the contactor and its weight. In the aeronautical field, the insulation distance between the fixed and moving contacts is further increased, which leads to even heavier and more bulky contactors. However, these criteria are critical, so there is a need for a less massive and more compact contactor, capable of interrupting an electrical connection with a voltage usually of the order of 1600 volts and of extinguishing the electric arcs forming during such a break.

[0008] Another known solution could be to multiply the number of contacts by connecting positive terminals to negative terminals and multiplying the number of breaking chambers, but this would again increase the size and mass of the contactor.

[0009] The known solutions are therefore not satisfactory. SUMMARY OF THE INVENTION

[0010] The invention provides a solution to the problems discussed above by using several contacts with double breaking points while pooling certain parts of each breaking chamber so as to provide an actuator comprising four electric arc extinguishing zones. While prior solutions encourage the skilled person to use simple breaking points with a rotary movement of the actuator, such actuation is however not suitable for double breaking points. The contactor according to the invention is therefore suitable for using a linear actuator.Furthermore, in order to avoid a phenomenon of post-cutting electrical re-breakdown between the fixed and moving contacts due to the potentials present, the person skilled in the art would be encouraged to increase the distance between the moving contacts and the fixed contacts in the open position of the moving bridge, the contactor according to the invention does not modify this distance, but is designed to divide by two the value of the voltage to be cut at the level of each pair of fixed and moving contacts.

[0011] One aspect of the invention relates to a contactor comprising a housing containing four bridges movable between a closed state and an open state, four breaker chambers arranged in two pairs of adjacent breaker chambers, an actuator comprising a movable shaft connected to the four movable bridges, the activation of the actuator causing the simultaneous movement of the four movable bridges between their closed state and their open state, and in which: the two pairs of adjacent breaker chambers are arranged in a rectangle and each divided into two electric arc extinguishing zones, each of the two pairs of breaker chambers comprises four movable bridges, each breaker chamber comprises: one of said four movable bridges each comprising a movable terminal equipped with a first movable contact and a second movable contact, a first fixed terminal equipped with a first fixed contact located opposite the first movable contact,a portion of said first fixed terminal projecting outside the housing, a second fixed terminal equipped with a second fixed contact located opposite the second movable contact, said second fixed terminal being common to two cutting chambers, and having a second fixed contact in each of said two cutting chambers which form a pair of adjacent cutting chambers,

[0012] two electric arc extinguishing devices, each being located in an electric arc extinguishing zone opposite a pair of fixed and movable contacts, each electric arc extinguishing device comprising two electric arc extinguishing blocks equipped with a plurality of fins.

[0013] By using a double-pole double-break contactor, the positive and negative terminals of an electric current source can be simultaneously cut off, each pole cutting half of the mains voltage, which allows the use of fin blocks and breaking chambers with the usual dimensions. Since the breaking chambers are parallel and joined to each other in order to arrange them in a rectangle, the size of the contactor is minimized. The weight and size of the contactor are also reduced by multiplying the number of double-break contacts without multiplying all the components, in particular the number of magnetic field emitting devices and the number of fixed terminals carrying fixed contacts.Similarly, the actuator used in the invention is only slightly larger than those used in previous contactors because it must exert twice the force on the moving bridges, but with an unchanged stroke value. Thus, thanks to the integration rate of the invention, the contactor provides double the breaking voltage with only an increase in the overall mass of the contactor of about 50%, which is very advantageous. Indeed, the invention makes it possible to double the breaking capacity in voltage with an increase in the total mass of about 50% for the device. The invention therefore makes it possible, for example, to go from 800V to 1600V for 50% more mass and not for 100% more mass, which would correspond to a doubling of the mass.

[0014] Furthermore, by using a double pole double break contactor, it is not necessary to increase the clearance distance J between the moving contacts and the fixed contacts. It will be noted that usually J is about 2 mm, which is sufficient for example to break a voltage of 800 volts. The contactor of the invention dividing by two the voltage to be cut, it allows for example to cut a voltage of 1600 volts, by cutting twice a voltage of 800 volts, and can therefore use a clearance distance J of approximately 2 mm between the moving contacts and the fixed contacts. This is extremely advantageous, because to cut a voltage of 1600 volts, a distance of J of approximately 2 mm would be largely insufficient and would result in a phenomenon of post-cutting electrical re-breakdown between the moving contacts and the fixed contacts, and increasing the value of J would increase the size of the actuator almost exponentially. Indeed, if the value of J were increased, then it would also be necessary to increase the total stroke of the actuator. Increasing this stroke would imply a much larger and therefore much heavier actuator. The relationship between stroke and size / mass is not at all linear, this increase would therefore be almost exponential.This is also why in the aeronautics sector, we use J values ​​that are much lower than in other sectors of activity.

[0015] In addition to the characteristics which have just been mentioned in the preceding paragraph, the contactor according to one aspect of the invention may have one or more additional characteristics among the following, considered individually or according to all technically possible combinations: The two adjacent arc chutes within each pair are identical and mirrored to each other. The two pairs of arc chutes are identical and mirror each other. Each electric arc extinguishing device comprises a magnetic field emitting device and two electric arc extinguishing blocks equipped with a plurality of fins and located at a distance on either side of one end of the movable bridge, each arc extinguishing chamber comprising a first magnetic field emitting device located at a distance from the first movable contact and the first fixed contact, and a second magnetic field emitting device located at a distance from the first movable contact and the first fixed contact, said second magnetic field emitting device being common to two adjacent arc extinguishing chambers. Within each pair, each breaker chamber comprises a first separating wall common to the two breaker chambers and separating them, and in that the second fixed terminal passes through the first separating wall. Each pair of arc chutes includes a second dividing wall common with the other adjacent pair of arc chutes and separating the two pairs of arc chutes. The second magnetic field emitting device passes through the separating wall. The actuator is a linear actuator. The movable axis of the actuator is connected to four bars each equipped with an axis secured to one of said movable bridges. The four bars are arranged in an X.

[0016] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0017] The figures are presented for information purposes only and in no way limit the invention.

[0018] [Fig. 1] is an overall plan schematic view from above of a contactor according to the prior art comprising two juxtaposed breaking chambers, each comprising two electric arc extinguishing zones equipped with two electric arc extinguishing blocks.

[0019] [Fig. 2] is a schematic cross-sectional view of a contactor along axis 11-11 of Figure 1.

[0020] [Fig. 3] is a schematic longitudinal sectional view of a contactor along axis III-III of Figure 1.

[0021] [Fig. 4] is an overall plan schematic view from above of an example of a contactor according to the invention comprising four juxtaposed breaking chambers.

[0022] [Fig. 5] is a schematic cross-sectional view of a contactor along the VV axis of Figure 4.

[0023] [Fig. 6] is a schematic longitudinal sectional view of a contactor along axis VI-VI of Figure 4. DETAILED DESCRIPTION

[0024] The figures are presented for information purposes only and in no way limit the invention. Unless otherwise specified, the same element appearing in different figures has a single reference.

[0025] The double-break contactor 1 of the invention is preferably a high-voltage direct current (HVDC) contactor. The principle of the invention can, however, be adapted to any type of direct current contactor, including all switches and all circuit breakers in which electric arcs are likely to be generated. Due to the symmetry of the contactor 1, its fixed terminals 6a can be either positive or negative terminals.

[0026] The contactor 1 of the invention is characterized in that it comprises four breaking chambers 2 arranged in a rectangle. By arranged in a rectangle, it is meant that the four breaking chambers are each provided at the corner of a rectangle.

[0027] The two adjacent breaking chambers 2 within each pair C1, C2 are preferably identical and mirror each other.

[0028] When we speak of two elements mirroring each other, we mean that these elements have a symmetrical configuration with respect to the orthogonal plane that separates them.

[0029] The two pairs C1, C2 of breaking chambers 2 are also preferably identical and mirror each other.

[0030] The cutting chambers 2 are preferably housed in a housing 16 in order to protect what they contain.

[0031] The four extinguishing chambers 2 are provided in two pairs C1, C2. Within each pair C1, C2, the two extinguishing chambers 2 are adjacent, while the two pairs C1, C2 are also adjacent.

[0032] Each arc extinguishing chamber 2 is divided into two electric arc extinguishing zones 8, for example by one or more separating partitions 9.

[0033] Within each pair C1, C2 of arc chutes 2, each arc chute 2 comprises a movable bridge 3 between a closed state and an open state, comprising a movable terminal 4 equipped with a first movable contact 5a and a second movable contact 5b, a first fixed terminal 6a equipped with a first fixed contact 7a located opposite the first movable contact 5a, a portion of said first fixed terminal 6a projecting outside the housing 16, a second fixed terminal 6b equipped with a second fixed contact 7b located opposite the second movable contact 5b, said second fixed terminal 6b being common to the two arc chutes 2, two electric arc extinguishing devices 17, each being located in an electric arc extinguishing zone 8.

[0034] Depending on how the contactor 1 is electrically connected, one of the first fixed terminals 6a of each pair C1, C2 is a positive pole terminal while the other is a negative pole terminal. For example, in [Fig. 4], the first fixed terminal 6a shown at the bottom left of the first pair C1 is a positive pole terminal while the first fixed terminal 6a shown at the bottom right of the second pair C2 is a negative pole terminal. In order to illustrate a mode of use of the contactor 1, in [Fig. 4], a load 21 is shown between a positive pole fixed terminal 6a and a negative pole fixed terminal 6a, these two fixed terminals 6a being shown at the top in the figure, the other two fixed terminals 6a being usually connected to a source of electric current. The load 21 can be any device requiring to be supplied with electrical energy for its operation, for example an electric motor.

[0035] The contactor 1 of the invention is also characterized in that it comprises an actuator 18 comprising a movable axis connected to the four movable bridges 3, the activation of the actuator 18 causing the simultaneous movement of the four movable bridges 3 between their closed state and their open state.

[0036] According to a preferred embodiment of the invention, the actuator 18 is a linear actuator. The actuator 18 is preferably of the electromagnetic type. It is preferably positioned at the meeting point of the four breaking chambers 2.

[0037] The movable axis of the actuator 18 is preferably secured to four bars 19 each equipped with an axis 20 secured to one of said movable bridges 3. At least the bars 19 or the axes 20 are made of an electrical insulator. Preferably, the bars 19 are made of plastic, and the axes 20 are made of metal, for example steel or aluminum. The bars 19 preferably have sufficient stiffness to limit the deflection and not create significant misalignment.

[0038] According to a preferred embodiment of the invention, the four bars 19 are arranged in an X. Thus, the bars 19 are preferably provided in the same plane and arranged in a cross, the angles of this cross preferably being non-right.

[0039] By closed state is meant a configuration in which an electric current / can flow through the contactor 1 , while by open state is meant a configuration in which no electric current / can flow.

[0040] When each movable bridge 3 is in the closed state, within each pair C1, C2, an electric current / moves from a first fixed terminal 6a to the second fixed terminal 6b, then to another first fixed terminal 6a, each time crossing a movable bridge 3.

[0041] Conventionally, each movable bridge 3 is spring-mounted. The spring device is not shown in the figures for reasons of clarity.

[0042] [Fig. 4] to [Fig. 6] represent the movable bridge 3 in the open state and the flow of current / is symbolized by a succession of dotted arrows. When a movable bridge 3 is opened, the movable contacts 5a, 5b are moved away from the fixed contacts 7a, 7b and an electric arc 11 is likely to appear between the contacts 5a, 5b, 7a, 7b located opposite each other. The role of each electric arc extinguishing device 17 is to quickly extinguish these electric arcs 11.

[0043] Each electric arc extinguishing device 17 preferably comprises a magnetic field emitting device 10a, 10b and two electric arc extinguishing blocks 12 equipped with a plurality of fins 13 and located at a distance on either side of one end of the movable bridge 3. Thus, each arc extinguishing chamber 2 comprises a first magnetic field emitting device 10a located at a distance of the first movable contact 5a and of the first fixed contact 7a, and a second magnetic field emitting device 10b located at a distance from the first movable contact 5a and of the first fixed contact 7a, said second magnetic field emitting device 10b being common to two adjacent cutting chambers 2.

[0044] Conventionally, each magnetic field emitting device 10a, 10b is part of an arc blowing device provided to deflect each electric arc 11 towards an electric arc extinguishing block 12. They each emit a magnetic field M of constant direction, exerting a Laplace electromagnetic force F on each electric arc 11 so as to move it towards the nearest electric arc extinguishing block 12. These movements can be guided by two arc guides 14 located opposite each other and each located between an electric arc extinguishing block 12 and a movable contact 5a, 5b. Each magnetic field emitting device 10a, 10b can for example comprise one or more magnets and / or one or more coils. Magnets are however preferred.

[0045] It will further be noted that for each electric arc extinguishing device 17, the contactor 1 according to the invention preferably incorporates a solution disclosed by the French patent application having the application number FR2211610 and the publication number FR3141796A1, which consists of equipping the circuit breaker contactors with a device for cooling and deionizing the ionized cut-off gases before their discharge to the outside. This solution is based on the use of inclined fins and concave internal surfaces of curved section which deflect the flow of cut-off gas towards the electric arc along a return loop path towards the middle part of the electric arc extinguishing zone, reinforcing the safety role of the electric arc extinguishing device. This solution is visible in [Fig. 3] and [Fig. 6].

[0046] According to a preferred embodiment of the invention, within each pair C1, C2, each arcuate chamber 2 comprises a first separating wall 15a common to the two arcuate chambers 2 and separating them. The second fixed terminal 6b preferably passes through the first separating wall 15a. Similarly, the second magnetic field emitting device 10b preferably passes through the separating wall 15a.

[0047] Furthermore, according to a preferred embodiment of the invention, each pair C1, C2 of cutting chambers 2 comprises a second separating wall 15b common with the other pair C1, C2 of adjacent breaker chambers 2 and separating the two pairs C1, C2 of breaker chambers 2.

[0048] Each breaking chamber 2 is preferably delimited by the walls of the housing 16 and the separating walls 15a and 15b. The contactor 1 may also comprise one or more closing walls 22 of the breaking chambers 2, located between the fixed terminals 6a and 6b and the bars 19. Each closing wall 22 preferably has at least one through-hole for the passage of the axes 20. The fixed terminals 6a and 6b are preferably secured to the closing walls 22.

[0049] Although described through a number of examples, variations and embodiments, the contactor according to the invention includes various variations, modifications and improvements which will be obvious to those skilled in the art, it being understood that these variations, modifications and improvements are part of the scope of the invention.

Claims

CLAIMS

1. Contactor (1) characterized in that it comprises a housing (16) containing four movable bridges (3) between a closed state and an open state, four breaking chambers (2) arranged in two pairs (C1, C2) of adjacent breaking chambers (2), an actuator (18) comprising a movable axis connected to the four movable bridges (3), the activation of the actuator (18) causing the simultaneous movement of the four movable bridges (3) between their closed state and their open state, and in that: - the two pairs (C1, C2) of adjacent arc extinguishing chambers (2) are arranged in a rectangle and each divided into two electric arc extinguishing zones (8), - each of the two pairs (C1, C2) of breaking chambers (2) comprises four movable bridges (3), - each breaking chamber (2) comprises: o one of said four movable bridges (3) each comprising a movable terminal (4) equipped with a first movable contact (5a) and a second movable contact (5b), o a first fixed terminal (6a) equipped with a first fixed contact (7a) located opposite the first movable contact (5a), a portion of said first fixed terminal (6a) projecting outside the housing (16), o a second fixed terminal (6b) equipped with a second fixed contact (7b) located opposite the second movable contact (5b), said second fixed terminal (6b) being common to two breaking chambers (2), and having a second fixed contact (7b) in each of said two breaking chambers (2) which form a pair (C1, C2) of adjacent breaking chambers (2), o two electric arc extinguishing devices (17), each being located in an electric arc extinguishing zone (8) opposite of a pair of fixed (7a, 7b) and mobile (5a, 5b) contacts,each electric arc extinguishing device (17) comprising two electric arc extinguishing blocks (12) equipped with a plurality of fins (13).,

2. Contactor (1) according to claim 1, characterized in that the two adjacent breaking chambers (2) within each pair (C1, C2) are identical and mirror each other.

3. Contactor (1) according to claim 1 or 2, characterized in that the two pairs (C1, C2) of breaking chambers (2) are identical and mirror each other.

4. Contactor (1) according to any one of the preceding claims, characterized in that each electric arc extinguishing device (17) comprises a magnetic field emitting device (10a, 10b) and two electric arc extinguishing blocks (12) equipped with a plurality of fins (13) and located at a distance on either side of one end of the movable bridge (3), each breaking chamber (2) comprising a first magnetic field emitting device (10a) located at a distance from the first movable contact (5a) and the first fixed contact (7a), and a second magnetic field emitting device (10b) located at a distance from the first movable contact (5a) and the first fixed contact (7a), said second magnetic field emitting device (10b) being common to two adjacent breaking chambers (2). [Claim s] Contactor (1) according to any one of the preceding claims, characterized in that, within each pair (C1, C2), each breaking chamber (2) comprises a first separating wall (15a) common to the two breaking chambers (2) and separating them, and in that the second fixed terminal (6b) passes through the first separating wall (15a).

6. Contactor (1) according to any one of the preceding claims, characterized in that each pair (C1, C2) of breaking chambers (2) comprises a second separating wall (15b) common with the other pair (C1, C2) of breaking chambers (2) adjacent and separating the two pairs (C1, C2) of breaking chambers (2).

7. Contactor (1) according to claims 4 and 5, characterized in that the second magnetic field emitting device (10b) passes through the separating wall (15a). [Claim s] Contactor (1) according to any one of the preceding claims, characterized in that the actuator (18) is a linear actuator.

9. Contactor (1) according to any one of the preceding claims, characterized in that the movable axis of the actuator (18) is connected to four bars (19) each equipped with an axis (20) integral with one of said movable bridges (3).

10. Contactor (1) according to the preceding claim, characterized in that the four bars (19) are arranged in an X.

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