CN1186793C - High-voltage electric switch unit with composite motion - Google Patents

Abstract

A high-voltage circuit breaker includes: a first contact device (12), which is driven by a drive mechanism (14); an exhaust pipe (16), which is firmly engaged with the first contact device (12); and a second contact device ( 18) Kinematically coupled to the coupling by a transmission mechanism (20) with a cam (84) which realizes a variable speed ratio V ₂ /V ₁ between the second and first contact means. When the first contact device approaches its breaking position, the ratio V ₂ /V ₁ is less than 0.5, increases to a maximum value greater than 1.2 when approaching the separation position of each contactor, and then falls back below 0.5 again when approaching the breaking position . This facilitates the pressure build-up at the beginning of the breaking and the extinguishing of the arc at the end of the breaking, and at the same time achieves a high relative velocity of the contactors when separation takes place.

Description

High voltage electrical switchgear with double movement

Technical field

The invention relates to a high-voltage electrical switchgear with multiple movements of contactors.

Background technique

Various live switchgears, switches, disconnectors or circuit breakers are known for high voltages and especially extra high voltages, comprising two separable centering contactors and a means for urging one of the two contactors to operate relative to the other. Manipulating mechanism for translational movement.

In document FR1448854 it is proposed a contactor with two translational movements arranged in a sealed envelope. The first contactor is driven by the operating mechanism and is equipped with a device for driving the second contactor to cause a uniform movement of the two contactors at the beginning of the breaking stroke, so that the two contactors do not separate immediately. The positive latching device can separate the two contactors at a predetermined position in their stroke, and a return spring urges the second contactor back to its original position while the first contactor continues its stroke after the two contactors have separated . A device of this type presents the advantage of increasing the separation speed of the contactors for a given separation stroke to rapidly lengthen the arc that occurs between the contactors at the moment the contactors separate. However, this requires a powerful drive, since the drive must achieve compression of the return spring at the beginning of the switching stroke. Secondly, the travel of the second contactor after disengagement is completely independent of the travel of the first contactor, since there is no longer any mechanical connection between the two contactors outside the disengaged position. In the event of failure of the reset mechanism that returns the second contactor to its rest position, the second contactor may remain stuck in its intermediate disengaged position while the first contactor is driven by the drive mechanism to its open position. In this case, the drive mechanism shows the separation position, while in fact the separation distance is not of concern.

An electrical switchgear comprising a sealing envelope filled with a dielectric gas is described in document HS3896282. First and second movable contacts are disposed within the envelope and generally engage each other to allow current flow. To unlatch the two contactors and interrupt the current flow, a mechanism with linkages and a crank enables the two contactors to be driven simultaneously at equal speeds in opposite directions relative to the envelope. The separation speed is greater than in switching devices where only one of the two contactors is allowed to move. Second, the linkage and crank mechanism create a mechanical connection between the first and second contactors at all times, so that the position of the second contactor is always linked to the position of the first contactor and to the drive mechanism s position. However, the energy required, especially at the start of the uncoupling, is great, since the two movable masses formed by the two contactors always have to be driven. Additionally, this unit does not include any arcing contactors, which makes it unsuitable for high performance switching. Finally, the connecting rods of the reset mechanism create space problems inside the sealing envelope.

A high voltage electrical switch comprising a sealed envelope filled with a dielectric gas and housing movable contactor means and a stationary contact means is set forth in document EP313813. The movable contact means includes a permanent contactor and an arcing contactor fixedly engaged with each other and an exhaust pipe made of insulating material fixed to the permanent contactor. The movable contact device is axially driven by a drive mechanism to move in translation in the envelope. The stationary contact means includes a permanent contact fixed relative to the envelope and an arcing contact which slides axially within a sliding contact which makes electrical contact with the stationary permanent contact. A transmission mechanism with a sprocket and a crown wheel enables the translational movement of the movable contact device to be transmitted to the sliding arcing contactor of the stationary contact device. The arcing contactor of the stationary contact device has a tubular shape such that the arcing contactor of the movable contact device protrudes deeply into the arcing contactor of the stationary contact device when the switch is closed. When opening of the switch occurs, the movable permanent contactor leaves the stationary permanent contactor before each arcing contactor leaves. When separation of each arcing contactor occurs, the arcing contactors are driven relative to each other at a speed twice the speed of the movable permanent contactor relative to the stationary permanent contactor. This arrangement enables the limitation of the moving mass, since one of the permanent contacts remains stationary relative to the envelope. However, it does require a drive mechanism with a large stroke, since the separation distance between the permanent contacts in the disengaged position is achieved only by the displacement of the movable permanent contact.

A device developed from previous devices is described in document DE19631323. The switch includes a first contact device and a second contact device. The first contact device includes a permanent contactor, an arcing contactor and an exhaust pipe made of insulating material, constituting a single assembly directly driven by a driving mechanism. The second contact means includes a permanent contactor and an arcing contactor fixedly engaged with each other. The movement of the arcing contactor of the first contact device is transmitted to the second contact device by means of a transmission mechanism, which includes a movement reverse lever, a first connecting rod hinged on the exhaust pipe and the lever, and a A second link hinged on the second contact means and on the lever. When uncoupling of the switch occurs, the arcing contactors separate at opposite speeds, the modulus of these speeds being equal. The moving mass is large because it includes two arcing contactors and two permanent contactors. The drive mechanism needs to be dimensioned accordingly. One of the various important breaking tests is a low intensity capacitive current breaking test. In order to break this current, the distance between the arcing contactors must be increased rapidly from the moment of separation, breaking the short-circuit current at the same time, and as long as the distance achieved between the contactors is less than one current string cycle and Just wait for the current to cross zero. The device cannot enable the kinetic energy to be optimized in this case.

A switch comprising a first contact means and a second contact means is described in document US5578806. The first contact device includes a permanent contactor, an arcing contactor and an exhaust pipe made of insulating material, forming a single assembly directly driven by the driving mechanism. The second contact means includes a permanent contactor and an arcing contactor fixedly engaged with each other. The movement of the arcing contactor of the first contact device is transmitted to the second contact device by means of a transmission mechanism consisting of a transmission cog, a crown wheel firmly engaged with the exhaust pipe and meshed with the cog and a A connecting rod which is hinged on the one hand at a point on the periphery of the cog wheel and on the other hand on the second contact means. The transmission mechanism is non-linear, which makes it possible to apply a low speed on the second contact means at the beginning of the movement when the separation of the permanent contactors occurs, so as to increase the speed when the separation of the arcing contactors, and subsequently in the Untie the end of the stroke to reduce speed. It is thus possible to disconnect the capacitive current without dissipating excessive driving energy. However, this arrangement does not allow the kinetic energy of the system to be optimized.

The document EP809269 describes a kind of equipment, including: the first contact device, which is composed of a permanent contactor, an arcing contactor and an insulating exhaust pipe, the arcing contactor and the insulating exhaust pipe form a direct drive mechanism Actuated monocoque assembly; second contact means including a stationary permanent contactor, an arcing contactor and a dielectric shield. A transmission mechanism connects the exhaust pipe to the arcing contactor of the second contacting device. The transmission mechanism includes a movement reverse lever; a connecting rod, which connects the lever to the arc contactor; and a straight rod, which is fixed to the exhaust pipe and slides in the straight groove of the lever. The transmission is non-linear in the sense that the ratio between the speed of the exhaust pipe and the speed of the arcing contactor of the second contact means is not constant. However, throughout the uncoupling stroke, the velocity of the exhaust pipe remains much greater than that of the arcing contactor of the second contact device, while the moving mass firmly connected to the exhaust pipe, also including the first contact device, is faster than that of the second contact device arcing contactor. The moving mass of the arcing contactor ground-engaged with the second contact device is much greater. In general, the kinetic energy of the mechanism is not optimized during unwinding.

Document FR2491675 describes a gas self-explosive and self-pressurizing type circuit breaker, comprising: a first contact device consisting of a permanent contactor, an arcing contactor and an insulating exhaust pipe, an arcing contactor and an insulating exhaust pipe Consists of a monocoque assembly directly driven by a drive mechanism; a first contact device comprising a static permanent contactor and an arcing contactor. A transmission mechanism connects the exhaust pipe to the arcing contactor of the second contacting device. The first contact means forms a cylinder, through holes of small diameter towards the exhaust duct and closed on the opposite side by a fixed piston, so as to constitute a variable volume quenching chamber. When the first contact means moves, the piston enters the extinguishing chamber and the volume of the chamber decreases. At the beginning of uncoupling, the movement of the first contact means increases the pressure in the extinguishing chamber as long as the second arcing contactor blocks the orifice of the exhaust pipe. Once the arcing contactors are separated, the second arcing contactor releases the orifice of the exhaust pipe. The volume of the arc extinguishing chamber continues to decrease and the gases escaping from the extinguishing chamber through the orifices help to extinguish the arc that occurs between the arcing contacts. In the case of unwinding at high currents, arc quenching must continue to continuously introduce the cooler gases contained in the quenching chamber to the arc until the arc is extinguished. In other words, the action of the piston is necessary throughout the entire process of the unlatching action. Therefore, the velocity of the first contact means relative to the piston must be sufficient so that the pressure in the quenching chamber remains greater than the pressure at the location of the exhaust pipe. In this document, it has been proposed to provide a transmission mechanism to give the contactor supporting the exhaust pipe a speed lower than or equal to the speed of the contactor not supporting the exhaust pipe, in order to reduce the kinetic energy of the system. The speed ratio remains constant during the breaking stroke, which is very suitable for the various needs of this type of circuit breaker, and is especially suitable for the requirement of continuously extinguishing the arc by compressing the extinguishing chamber. However, it is difficult to transpose the teaching of this document to a circuit breaker comprising a compression piston. In this case, it is in fact necessary to achieve a great piston speed in order to rapidly increase the pressure in the arc extinguishing chamber at the beginning of the breaking stroke on the one hand, and at the end of the breaking stroke on the other hand. It is more effective to extinguish the arc. Since the piston is usually firmly engaged to the contactor supporting the exhaust pipe, it is the piston that applies the velocity of the exhaust pipe.

Contents of the invention

The object of the present invention is therefore to overcome the various drawbacks of the current state of the art in order to propose a high-voltage switchgear with compression effect, high performance and enabling fast and reliable disconnection.

According to the invention, this object is achieved by means of a high-voltage live electrical switching device in a sealed envelope filled with a gas of high dielectric strength and defining a geometric reference axis, which device comprises:

fixed support, defining a compression volume,

The first contact device is movable relative to the support and includes:

first permanent contactor,

an exhaust pipe, made of electrically insulating material, firmly engaged to the first permanent contactor,

A piston, fixedly engaged to the first permanent contactor and sliding in a seat so as to define and separate an arc expansion volume from the compression volume together with the exhaust pipe, the piston is equipped with a discharge valve for discharge from the compression volume discharges to the arc expansion volume, this valve opens when the pressure in the compression volume becomes greater than the pressure in the arc expansion volume,

a first arcing contactor securely engaged with the first permanent contactor and extending into the arc extension volume;

second contact means comprising a second permanent contactor and a second arcing contactor movable relative to the envelope;

The drive mechanism drives the first contact device from a closed position to an open position by means of an axial translational movement along the reference axis, through a transitional separation position P ₂ of the first and second permanent contactors, at Here the first and second permanent contactors lose contact with each other, and through a transitional separation position P ₃ of the first and second arcing contactors, the transitional separation position P ₂ of the first and second permanent contactors and the open between the off position, where the first and second arcing contactors lose contact with each other;

The transmission mechanism forms a permanent motion connection between the exhaust pipe and the second arcing contactor so as to transmit the movement of the exhaust pipe to the second arcing contactor. The transmission mechanism is when the first contact device uses a model When the speed of the number V ₁ moves axially in the first direction, the second arcing contactor moves along the parameter axis in the opposite direction at the speed of the modulus V ₂ having a ratio V ₂ /V ₁ to the modulus V ₁ Translational movement, the ratio V ₂ /V ₁ is varied according to the position of the first contact means relative to the envelope in such a way that

_The ratio V ₂ /V ₁ remains at a value lower than 0.5 as long as the first contact means is between the closed position and the first transitional index position P ₁ which resides between the closed position and the first and second between the arc contactor transition separation position _P3 ,

the ratio V ₂ /V ₁ passes a maximum value greater than 1 when the first contactor passes through a second transition index position P ₅ lying between the first and second permanent contactor transition disengagement position P ₂ and the breaking position,

The ratio V ₂ /V ₁ remains at a value lower than 0.5 as long as the first contact means is between a third transition index position P ₇ located at the second transition index position P ₇ and the breaking position. Between position P ₅ and the break position.

The reliability of the device derives from the fact that the kinematic linkage achieved by the transmission mechanism is permanent, so that the position of the first contact means and the position of the operating mechanism provide a true picture of the position of the second arcing contactor.

The speed ratio employed between the closed position and the first transition index position enables the heavier first contact means to be accelerated rapidly at the initiation of opening just before separation of the arcing contactors occurs. This thus enables all available energy to be devoted to driving the piston, which acts to compress the gas contained in the compression volume. Once the pressure in the compression volume increases, the discharge valve opens allowing the pressure in the arc expansion volume to also increase. When separation of the arcing contactors takes place, the pressure in the arc extension volume is already high, which favors the breaking of the capacitive current. It is in fact known that the breakdown voltage between two electrodes charged at different potentials in a given gaseous medium is the minimum voltage required to generate an arc between two electrodes in the gaseous medium under consideration The voltage, given by Paschen's law, is a function of the product of the gas pressure and the distance separating the two electrodes, and it is also known that above a minimum value this function increases with the product of pressure and distance. By increasing the pressure in the arc extension volume, the breakdown voltage is thus increased and arc breakage between the arcing contactors is prevented.

The speed ratio used when the first contact means passes through the second transition index position is such that the energy of the movable assembly is significantly reduced at a time when the speed obtained by the piston is sufficient and can be used to rapidly increase the separation of the various parts. arc contactor distance. Indeed, if we consider on the one hand the first movable assembly consisting of moving masses firmly engaged with the first contactor, and on the other hand the moving mass consisting of moving masses firmly engaged with the second arcing contactor For the second movable component, we can see that the first movable component has a mass M ₁ greater than the mass M ₂ of the second movable component. This can be explained by the fact that the first contactor is firmly engaged on the one hand to the exhaust pipe and on the other hand to a part of the drive mechanism. By taking the speed V ₂ of the second contactor over the speed V ₁ of the first contactor, the kinetic energy of the entire movable mass is reduced. Thereby a separation velocity V ₁ +V ₂ with excellent energy efficiency is obtained. This arrangement is particularly useful for preventing arc breaks in the case of a capacitive current breaking test.

The speed ratio used when the first contact means passes through the third transition index position again enables all the kinetic energy available at the end of the breaking stroke to be devoted to the first contact means coupled to the piston in order to facilitate The arc extinguishing is very important for breaking the overload current, and the heated and dirty gas can be replaced by clean fresh gas when the breaking is completed.

Preferably, the second transition index position P ₅ is located between the transition separation position P ₃ and the breaking position of the first and second arcing contactors. This selection enables the kinetic energy of the device to be optimized precisely at the point in the contact stroke selected for extinguishing the arc connected to the capacitive current.

Preferably, the maximum value of V ₂ /V ₁ is greater than 1.5. The increase in the relative speed of the individual arcing contactors is thus further facilitated.

Preferably, the second permanent contact means and the second arcing contact means are firmly engaged with each other. This solution does in fact have the effect of increasing the moving mass of the system as a whole compared to a solution in which only the second arcing contactor is movable. However, this additional mass of movement does not appear to be detrimental in view of the effects sought. The optimum efficiency of the mechanism is in fact obtained for a speed ratio V ₂ /V ₁ equal to the ratio of the masses of the movable components on each side of the transmission. If the mass _M2 of the movable assembly of the second contact means is low, the ratio _M1 / _M2 will be very high and it will be difficult in practice to realize a transmission mechanism which is simple in structure and which ensures such a maximum transmission ratio without Also ensure lower transmission ratio values at the beginning and end of the stroke.

Preferably, the first contact means together with the exhaust pipe form a first movable assembly with a mass _M1 , and the second permanent contact means and the second arcing contact means form a second movable assembly with a mass _M2 , and when the first contact device passes the first transition label position, the velocity ratio confirms the relation:

$\mathrm{<span\; class="notranslate">\; 0.8</span>}\frac{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="C0114252400221.png,C0114252400231.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; \&le;</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 1.2</span>}\frac{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="C0114252400221.png,C0114252400231.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; .</span>$

It is desirable that the maximum value of the ratio V ₂ /V ₁ be as close as possible to the ratio M ₁ /M ₂ to minimize the kinetic energy of the system during the high speed separation phase of each arcing contactor. In the optimized case, when the first contact device passes the first transition label position, the speed ratio confirms the relation:

$\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="C0114252400221.png,C0114252400231.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; .</span>$

According to one embodiment, the transmission mechanism includes:

the cam pivots about a geometric axis fixed relative to the envelope and includes a curved track,

a slider securely engaged with the second arcing contactor and operating in conjunction with the track, and

Connecting rod, hinged on the gear and a part firmly attached to the exhaust pipe.

By an appropriate choice of the shape of the curved track, some of the speed ratios required during the opening and closing strokes can be derived very simply.

According to another embodiment, the transmission mechanism includes:

the cam pivots about a geometric axis fixed relative to the envelope and includes a first curved track and a second curved track,

the first slider is securely engaged with the second arcing contactor and operates in conjunction with the first track, and

The connecting rod system is firmly connected to the exhaust pipe and includes a second slider that works in conjunction with the second track.

This mechanism has the advantage of being able to directly guide the linkage system.

Advantageously, the exhaust duct comprises a neck forming a first gas flow path for gas flow from the arc expansion volume to a gas expansion volume inside the envelope, this first path being at least partially controlled by the second arcing contactor To make it closed, as long as the first contact device is between the closed position and a fourth transition index position P ₆ , and the fourth transition index position P ₆ is located between the transition separation position P 3 and the transition separation position P ₃ of the first and second arcing contactors between break positions.

Preferably, the device includes a second gas flow path for gas flow between the arc expansion volume and the gas expansion volume of the envelope, this path being equipped with a delay valve, provided that the first contact means is in the closed position and a fifth transition The valve remains closed between the indexed position _P4 and the fifth transitional indexed position _P4 is between the transitional disengaged position _P3 and the open position of the first and second arcing contactors. The two gas flow paths are in a competitive state, which can increase the gas ejection rate. The valve enables the initiation of opening of the gas flow path to be precisely determined after disconnection of the arcing contactors. The time interval elapsed between the separation of each arcing contactor and the opening of the valve is utilized to continue the gas expansion volume caused by the combination of the piston and the arc drawn between the arcing contactors when each arcing contactor was separated. The pressure in it increases. Advantageously, the fourth transition index position P ₆ is located between the fifth transition index position P ₄ and the switch-off position. In other words, when implementing the opening sequence of the mechanism, the opening of the second path is prior to the opening of the first path. Preferably, the second transitional index position _P5 is located in the vicinity of the fourth transitional index position _P6 and the fifth transitional index position _P4 .

According to a preferred embodiment, the first arcing contactor comprises a tube through which the gas flow path passes.

Description of drawings

Other advantages and features will become more apparent from the following description of specific embodiments of the invention, which are presented as non-limiting examples and shown in the accompanying drawings, in which:

Figure 1 shows a schematic diagram of a circuit breaker in accordance with a first embodiment of the present invention in the breaking position;

Figure 2 shows a top axial sectional view of the circuit breaker of Figure 1 in the breaking position;

Figure 3 shows a bottom axial sectional view of the circuit breaker of Figure 1 in the breaking position;

Figure 4 shows a top axial sectional view of the circuit breaker of Figure 1 in the closed position;

Figure 5 shows a bottom axial sectional view of the circuit breaker of Figure 1 in the closed position;

Figure 6 shows a graph with respect to different speeds of a contact device position;

Figure 7 shows a detail of a second embodiment of the invention.

Detailed ways

Referring to Figures 1-5, a high voltage circuit breaker, in this case one designed for voltages in excess of 36KV, can be seen immersed in _a Among the envelope 10, and include: the first contact device 12 that is promoted by an operating mechanism 14; Exhaust pipe 16, it is firmly engaged in the first contact device 12; And the second contact device 18, it is by means of a motion transmission Mechanism 20 is movably coupled to exhaust pipe 16 . The envelope 10 makes it possible to define a fixed geometric reference axis 22 constituting the axis of movement of the moving parts.

The first contact device 12 , which can be seen in detail in FIGS. 2 and 4 , comprises a tubular cylindrical permanent contactor 24 and an arcing contactor 26 arranged coaxially inside the permanent contactor 24 . The arcing contactor 26 is also tubular and is provided at its free end with a pull-in tulip-petal contactor 28 of contact fingers arranged in a corolla. The permanent contact 24 is itself provided with a cylindrical terminal pull-in contact pad 30 enabling it to operate in conjunction with the second contact means 18 . The arcing contactor 26 and the permanent contactor 24 are securely engaged with each other and are driven together by the operating mechanism 14 .

The exhaust pipe 16 consists of a part made of an insulating material such as Teflon, making it possible to degas in the event of an arc. It is secured to an interior surface of the permanent contactor 24 and is positioned between the cylindrical terminal pull-in contact backing plate 30 of the permanent contactor and the tulip petal contactor 28 of the arcing contactor. The exhaust pipe has a neck 32 separating two reamed grooves 34, 36.

The terminal pull-in contactor backing plate 30 of the permanent contactor 24 is extended by a cylindrical outer peripheral surface of a sliding contact wall 38; the wall 38 slides axially inside a cylindrical catcher 40 , the catcher 40 is fixed relative to the envelope 10 used as a support and guide for the contact device 12; the catcher 40 is equipped with a sliding contact ring 41 for causing permanent contact when the permanent contactor 24 moves The electrical contact between the collector 24 and the trap 40. Cylindrical trap 40 defines an internal compression volume 42 hermetically sealed by a cylindrical head cap 44 . The permanent contactor 24 is provided with a piston 46 at its axial end protruding into the catcher 40, which connects the compression volume 42 with a cylindrical wall 38 formed by the permanent contactor 24 and opposite it. The axial ends of the piston 46 are separated by the arc expansion volume radially constrained by the exhaust pipe 16 . Piston 46 is provided with a discharge valve 50 which breaks off as soon as the pressure in compression volume 42 becomes greater than the pressure in arc extension volume 48 . Piston 46 securely engages permanent contactor 24 and arcing contactor 26 and forms a current path between permanent contactor 24 and arcing contactor 26 . Arcing contactor 26 is formed through piston 46 and barrel 52 of cylinder head cap 44 and projects inside a gas expansion volume 54 confined by cap 10 which is sealed. The gas expansion volume 54 occupies all the available space in the envelope up to the reamed recess 36 . The end of the tube 52 is fixed to a straight rod 56 constituting the output portion of the drive mechanism 14 . Side openings 58 are formed in the end of tube 52 such that a gas flow path 60 is formed between arc extension vessel 48 and gas expansion volume 54 through the inside of tube 52 . However, the locking sleeve 61, which is firmly engaged with the cylinder head cap 44 acting as a delay valve, tightly covers the orifices 58 in the closed position shown in FIG.

The cylinder head 44 is provided with a fill valve 62 and a drain valve 64 . The charge valve 62 enables communication from the gaseous expansion volume 54 to the compressed volume 42 when the pressure in the compressed volume 42 is lower than the pressure in the gaseous expansion volume 54 . When the pressure difference between the compression volume 42 and the gas expansion volume 54 is greater than the discharge threshold determined by a return spring 66 of the valve 64 , the relief valve 64 realizes communication from the compression volume 42 to the gas expansion volume 54 .

The second contact means 18, which can be seen in FIGS. 3 and 5, consists of a second permanent contactor 70 and a second arcing contactor 72 firmly engaged with each other. The permanent contactor 70 consists of a porous metal tube, one free end of which is provided with a contact gripper 74 in the shape of tulip petal-shaped fingers. The permanent contactor 70 slides axially within a fixed catcher 74 provided with a sliding contactor 76 which causes electrical contact between the permanent contactor 70 and the catcher 74 as the permanent contactor 70 moves. The second arcing contactor 72 constitutes a metal contact finger 78 having the same inner diameter as the neck of the exhaust pipe, extended by a metal straight rod 80 . The arcing contactor 72 and the permanent contactor 70 are secured to each other by means of a diametric crossbar 82 which also ensures current flow between the two contactors 70 , 72 .

The motion transmission mechanism 20 includes a pivotal return cam 84 operating in conjunction with an axial end of the straight rod 80 of the arcing contactor 72 and a thin transfer link 86 . The cam 84 is pivotable about a fixed geometric pivot axis 89 perpendicular to the reference axis 22 . The connecting rod 86 is hinged on the cam 84 and fitted on a crown 88 at one axial end of the exhaust pipe 16 . The axial end of the arcing contactor 72 is provided with a roller 90 which functions as a slider and operates in conjunction with a track formed by a sickle-shaped curved groove 92 formed on the cam 84 . One end of the travel return spring 94 pushes the cross bar 82 and the second contact device 18 to the closed position.

This device works in the following way:

In the closed position, in FIGS. 4 and 5 , the contact gripper 74 of the second permanent contactor 70 grips the outer periphery 30 of the first permanent contactor 24 and forms a path through the first catcher 40 , the sliding contactor 41 . The current paths of the first permanent contactor 24 , the contact gripper 74 , the second permanent contactor 70 , the sliding contactor 76 and the second catcher 76 . Contact fingers 78 forming the ends of the second arcing contactor 72 extend deeply into the first arcing contactor 26 and block the barrel 52 . The tulip-petal-shaped contact fingers 28 of the first arcing contactor 26 clamp the contact fingers 78 and form a second current path between the first and second catchers. Fingers 78 block the end of tube 52 formed by arcing contactor 26 so that the gas column contained within tube 52 is sealed. The finger 78 also occupies the entire interior of the neck 32 so that it also at least partially closes the arc extension volume 48 in this position.

When opening the device, the operating mechanism 14 continuously drives the first contact means 12 from the closed position shown in FIGS. 4 and 5 to the open position shown in FIGS. 1 to 3 . The movement of the first contact device 12 is transmitted to the second contact device 18 by means of the exhaust pipe 16 and the transmission 20 .

In order to describe the breaking motion principle more accurately, the speed of the first contact device 12 (curve A), the speed of the second contact device 18 (curve B), the speed of the second contact device 12 and the speed of the first contact device 18 The ratio between (curve C) versus the movement of the first contacting device 12 relative to the catcher 40 shown on the X-axis is shown in FIG. 6 .

The shape of the cam 84 is such that, during a first phase, the second contact means 18 remains virtually stationary, so that all the energy of the drive mechanism 14 is used for the purpose of accelerating the first contact means 12 . In other words, if we examine the velocity modulus V ₁ of the first contacting device 12 and the velocity modulus V ₂ of the second contacting device 18 , as long as the first contacting device is in the closed position with a denoted by P ₁ in the diagram Between the first transition label position, the ratio V ₂ /V ₁ is close to zero and in any case less than 0.5. Above _P1 , the first contacting device 12 reaches a disengaged position _P2 of the permanent contactors 24, 70 at approximately 10% of their full travel. Cam 84 has pivoted several degrees, so that the speed transfer ratio _V2 / _V1 increases rapidly beyond unity. When the first contacting device 12 reaches a position P ₃ at which it leaves the second arcing contactor 72 , it has already covered approximately 30% of its breaking travel and the speed ratio exceeds 1.5. The relative separation velocity of the arcing contactors, equal to V ₁ +V ₂ , is high. The ratio V ₂ /V ₁ remains greater than 1.5 for approximately 0.5 to 3 milliseconds, enabling very high speed separation of the arcing contactors 26 , 72 to occur and pass a maximum when the first contact reaches a position P ₅ . As long as the speed ratio V ₂ /V ₁ remains greater than 1, the acceleration of the lighter contact means, ie the second contact means 18 which does not support the exhaust pipe 16 , precedes the movement of the heavier contact means, ie the first contact means 12 . During this disengagement phase of the arcing contactors, for a given total mechanical force provided by mechanism 14, this tendency is such that the relative velocity V ₁ +V ₂ of the movable assembly is maximized. change. Indeed, if we examine a simplified model of the mechanical system involved, the maximum velocity is obtained due to:

$\frac{d(V_1+V_2)}{\mathrm{dt}}=0,$ That is, dV ₁ = -dV ₂

As a first approximation, the minimum force is obtained due to:

dW＝M ₁ V ₁ dV ₁ +M ₂ V ₂ dV ₂ ＝0

where _M1 is the mass of the moving parts firmly engaged to the first contact device 12, that is, as a first approximation, is the permanent contactor 24, the arcing contactor 26, the straight rod 56, the exhaust pipe 16 and the crown 88 , where M ₂ is the mass of each moving part firmly connected to the second contact device 18 , that is, the mass of the permanent contactor 70 , the arcing contactor 72 and the crossbar 82 .

Then we get:

M ₁ V ₁ −M ₂ V ₂ ＝0

This is equivalent to

$\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="m"\; filenames="C0114252400221.png,C0114252400231.png"\; state="\{\{state\}\}">m</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

This simplified model, which does not take into account the moving masses of the motion transmission, thus shows that if we want to maximize the relative velocity V ₁ +V ₂ and minimize the kinetic energy, it is to our advantage to make the ratio V ₂ /V ₁ The ratio M ₁ /M ₂ of the moving masses of each movable assembly close to the first and second contact means. In practice, the mass M ₁ of the first movable assembly, which also includes the exhaust pipe, is always greater than the mass M ₂ of the second movable assembly. The ratio M ₁ /M ₂ will tend to be high, about 1.5 to 2, so that it will be difficult to obtain a ratio V ₂ /V ₁ equal to the ratio of the masses. We will therefore be satisfied with a ratio V ₂ /V ₁ greater than 1.2, or preferably greater than 1.5, during the milliseconds after separation of each arcing contactor.

Transfer cam 84 is shaped in such a way that when the first contact means has traveled about 50% of its breaking travel, the velocity ratio _V2 / _V1 drops back below 1 and drops rapidly. When the first contact means passes a transition position _P7 , the speed ratio drops back below 0.5 and it becomes zero at about 90% of the breaking travel.

This purely kinematic account of the breaking makes it possible to distinguish the different phases.

The initial movement, before reaching _P1 , makes it possible to give the first contact means 12 the full energy delivered by the drive mechanism 14 and to trigger a pumping effect quickly. Once the movement of the piston generates a greater pressure in the compression volume 42 than in the arc extension volume 48 , the discharge valve 50 is opened and the gas located in the compression volume 42 begins to enter the arc extension volume 48 . The pressure in the arc extension volume 48 then begins to build as the contact fingers 78 block the escape passage 60 through the arcing contactor barrel 52 and through the neck 32 .

When the permanent contactor 24, 70 separates at _P2 , the current path through the permanent contactor 24, 70 is cut off. However, the auxiliary current path through the arcing contactors 26, 72 continues to exist because the contact fingers 78 are still partially engaged in the tulip petal-shaped contact finger contact gripper 28, so that when the separation of the arcing contactors is reached No arc is drawn between the permanent contactors 24, 70 prior to position _P3 . The pressure in the arc extension volume 48 continues to increase. From position _P3 onwards, the continuation of breaking depends mainly on the type of current flowing in the circuit breaker when breaking occurred. Breaking during short-circuit currents is successively distinguished from breaking during overload currents and breaking during capacitive currents.

When the circuit breaker opens on AC short circuit current, once the arcing contacts 26, 72 are separated, a very high energy arc occurs between the arcing contacts 26, 72 and takes up all available space, As a result, the pressure in the arc extension space 48 is greatly increased.

In addition, the arc causes degassing of the gas generating material of the exhaust pipe 16 to induce a further increase in pressure in the arc extension volume 48 . When separation of the arcing contactors 26, 72 occurs, the delay valve 61 still covers the orifices 58 so that gas is trapped in the arc extension volume 48, further facilitating the pressure buildup. After traveling a few more centimeters, the small holes 58 are exposed at point _P4 of the graph in FIG. To the gas expansion volume 54. Once the arcing contactor 72 has moved down below the neck 32, at point _P6 of the curve of FIG. The gas flows through the neck 32 to the gas expansion volume 54. However, these outlets are not sufficient to reduce the pressure in the arc extension volume 48 to any significant degree such that the pressure in the arc extension volume 48 exceeds the pressure in the compression volume 42 and the discharge valve 50 closes. As the breaking action continues, the piston 46 compresses the gas located in the compression volume 42 until a relief threshold is reached, beyond which the relief valve 64 opens and the gas remaining in the compression volume 42 is expelled. To the gas expansion volume 54, so that the continuation of the breaking action is not hindered. The arc then extinguishes when the current crosses zero. However, the pressure in the arc extension volume 48 does not drop rapidly enough to reopen the discharge valve 50 . In this mode of operation, the arc extension volume 48 and compression volume 42 are thus kept separate until the breaking is completed. When the first contact has traveled approximately 50% of its breaking travel, the speed ratio V ₂ /V ₁ drops back below 1 and decreases rapidly.

When the circuit breaker opens at AC overload current, a high energy arc occurs between the arcing contacts at position _P3 as soon as separation of the arcing contacts occurs. Due to the significant high voltage in the arc extension volume 48 at the end of the previous stage, the arc is very constrained. Secondly, the pressurized gas can provide higher heating capacity than the unpressurized gas, which can make it more effective to eject various hot gases generated by the arc. The arc releases a large amount of energy, causing the gas generating material of the coupling pipe 16 to degas and induce a further drop in pressure in the arc extension volume 48 so that the discharge valve 50 recloses. The outflow of gas is delayed until the orifices 58 are broken at point _P4 . Gas contained in the expansion volume escapes to the gas expansion volume via the inside of the arcing contactor barrel. Gas also escapes towards the bottom of the exhaust pipe 16 once the arcing contactor has moved down below the neck, beyond point P ₆ . The arc extinguishes when the current crosses zero. If the energy released by the arc is not too great, the pressure in the arc extension volume 48 drops rapidly causing the discharge valve 50 to reopen. When the first contact has traveled approximately 50% of its breaking travel, the speed ratio V ₂ /V ₁ drops back below 1 and decreases rapidly. During this phase, the energy available to the drive mechanism 14 is thus again used for the purpose of preemptively accelerating the first contact device 12 and thus moving the piston 46 in the compression volume 42 . Clean fresh gas is thus sent again from the compression volume 42 to the arc expansion volume 48 and to the arcing contactors 26, 72 until the breaking is completed, preventing re-strike of the arc between the arcing contactors.

According to the conditions of a capacitive test, when each arcing contactor separated at _P3 opens a capacitive circuit in which a weak current flows, a weaker arc is initiated between the arcing contactors 26, 72 between. This arc extinguishes itself almost immediately due to the good quality of the medium gas. The current is interrupted and the voltage between the contact means 12, 18 begins to increase rapidly. As the piston 46 moves in the compression volume 42 , a constant flow of fresh gas flows into the arc expansion volume 48 at increased pressure. As soon as the holes 58 are no longer blocked by the sleeve 61 (point P ₄ ), the gases escape via the tube 52 into the expansion volume 54 . In order to prevent re-strike of the arc between the contacts 12, 18, it is important that the voltage between the contacts 12, 18 is kept below the breakdown voltage. Within the operating range involved, however, Paschen's law states that the breakdown voltage is an increasing function of the product of the gas pressure and the separation distance of the individual contactors. It is therefore important that at the moment the arc is extinguished, the breakdown voltage is high and increases rapidly, in any case faster than the voltage across the arcing contactors.

This is in fact exactly the case achieved by the aforementioned kinematic characteristics. The point P ₅ corresponding to the maximum value of the speed ratio V ₂ /V ₁ is in fact located between the separation point P ₃ and the breaking position of each arcing contactor. Furthermore, this corresponds to a speed ratio greater than 1 which makes it possible to speed up the lighter contact means, namely the second contact means 18 which does not support the exhaust pipe 16, ahead of the heavier contact means, namely the first contact means. Movement of device 12 . For a given overall mechanical force provided by mechanism 14, this tendency maximizes the relative velocity V ₁ +V ₂ of the movable assembly as previously described.

In this phase we are thus directed to increasing the velocity V ₁ of the piston 46 in advance of increasing the relative separation velocity V ₁ +V ₂ of the arcing contact means. In other words, if we refer to Paschen's law, increasing the distance between the contactors precedes increasing the pressure. It should be noted, however, that the displacement of the piston 46 inside the compression volume 42 is sufficient to maintain, and even slightly increase, the pressure in the arc extension volume 48 higher than in the gas expansion volume 54, although due to the fact that the effective surface of the piston 46 is larger than the interior of the barrel 52 The cross-sectional and continuous gas flow flows through the arcing contactor 26 to the gas expansion volume 54 . However, the pressure build-up in the expansion volume is impeded by the respective airflow passages at the latest when the contact finger 78 is released from the exhaust pipe neck 32 and opens a second airflow passage through the neck 32 .

When the first contact device had reached 50% of its breaking stroke, the distance between the contactors was sufficient to prevent any re-strike of the arc under the various capacitive test conditions. The gas flows out from the compression volume 42 to the arc expansion volume 48 and continues until the interruption is completed.

Beyond point _P7 and under all breaking conditions, various clean fresh gases are sent from the compression volume 42 to the arc expansion volume 48 and the arcing contactors 26, 72 until the breaking is completed, preventing each arcing contact Any arcing between the devices re-ignites. Secondly, the end of the movement of the second contact means serves to compress the spring 94 .

Closing occurs in the opposite manner, noting that the filling valve 62 is now active to enable filling of the compression volume 42 . After the first 10% of the closing stroke, the second contact means 18 is activated. The spring 94 prevents any blocking of the transmission mechanism 20 at this time.

Of course, various improvements can be made.

Opening of each orifice 58 by delay valve 61 (at point _P4 ) occurs after separation of each contactor (at point _P3 of the curve), preferably after breaking off the exhaust pipe neck (at point _P6 ) Previously, the gas flow path with a smaller flow cross section, ie the path 60 , was preferably interrupted first. The positioning of the two points P ₄ and P ₆ relative to the point P ₅ which determines the maximum value of the speed ratio is not critical as long as the three points remain close to each other. According to a first alternative to the diagram of FIG. 6 , point P ₆ may lie between P ₄ and P ₅ . According to another alternative, point _P4 may be located between _P5 and _P6 . In some applications, it is possible to operate without delay valve 61 at all, so that as soon as finger 78 is removed from barrel 58 at point _P3 , air flow path 60 is opened, given that finger 78 In the closed position the barrel 52 is blocked.

Transmission mechanisms having different structures can be configured to obtain a speed curve equivalent to that of the first embodiment. FIG. 7 shows a detail of a second embodiment in which the transmission mechanism 120 includes a cam 184 which operates in conjunction with one end of the arcing contactor 80 on the one hand and with a link 186 on the other. The end of the arcing contactor 80 is provided, as in the first embodiment, with a roller 190a which has the function of a slider and operates in conjunction with a track 192a formed by a curvilinear groove made on the cam 184 . Likewise, the link 186 is provided at its end with a roller 190b which has the function of a slider and operates in conjunction with a track 192b formed by a second curved groove made on the cam 184 in the shape of a hook. The choice of the shape of the two tracks 192a and 192b facilitates obtaining speed ratios of the same type as those described for the first embodiment. Some other parts of the circuit breaker according to the second embodiment are identical to those of the first embodiment.

Furthermore it is possible to configure a valve, instead of the sleeve 61, to close the barrel close to the contact finger, in order to further facilitate the pressure build-up in the expansion volume at the initiation of breaking, especially in various capacitive test conditions Down.

In the described embodiments, the permanent contactor 70 is movable and securely engaged to the arcing contactor 72 . It is also conceivable to have a stationary permanent contactor 70 and an arcing contactor 72 driven solely by the transmission 20 .

Claims (15)

1. the charged air cock equipment of high pressure belt is also determined how much reference axis (22) in the sealing big envelope (10) in being full of a kind of high dielectric strength gas, comprising:

Hold-down support (40) defines a minimum cylinder volume (42),

First contact device (12), movable and comprise with respect to bearing (40):

The first permanent contactor (24),

Blast pipe (16) is made by electrical insulating material, is engaged in the first permanent contactor (24) securely,

Piston (46), be engaged in the first permanent contactor (24) securely and slip among bearing (40), so that limit electric arc expanded volume (48) and electric arc expanded volume (48) and minimum cylinder volume separated with blast pipe, piston (46) outfit drain valve (50) is used for the discharging from minimum cylinder volume (42) to electric arc expanded volume (48), this valve is open-minded when the pressure in the minimum cylinder volume (42) becomes greater than the pressure in the electric arc expanded volume (48)

First starting the arc contactor (26) is engaged in the first permanent contactor (24) securely and puts in electric arc expanded volume (48);

Second contact device (18) comprises second permanent contactor (70) and second starting the arc contactor (72) movable with respect to big envelope;

Driving mechanism (14) to make the mode of axial translation motion along reference axis (22), drives first contact device (12) to cut-offfing the position, by the transition separation point position (P of the first and second permanent contactors from make position ₂), the first and second permanent contactors lose contact each other herein, and the transition separation point position (P that passes through first and second starting the arc contactors ₃), occupy the transition separation point position (P of the first and second permanent contactors ₂) and cut-off between the position, first and second starting the arc contactors lose contact each other herein;

Transmission mechanism (20) constitutes perpetual motion contact so that give second starting the arc contactor (72) Motion Transmission of blast pipe (16) between the blast pipe (16) and second starting the arc contactor (72),

Be characterised in that transmission mechanism (20) is, when first contact device (12) has modulus V with one ₁Speed when first direction moves axially, second starting the arc contactor is to have and modulus V ₁Become a ratio V ₂/ V ₁Modulus V ₂Speed do translational motion along axis of reference (22) in the opposite direction, ratio V ₂/ V ₁Be to change as follows, that is: according to the position of first contact device (12) with respect to big envelope (10)

Ratio V ₂/ V ₁Keep below 0.5 numerical value, as long as first contact device (12) is at the make position and the first transition label location (P ₁) between, the first transition label location (P ₁) occupy the make position and the first and second starting the arc contactor transition separation point position (P ₃) between,

When first contact device (12) by occuping the first and second permanent contactor transition separation point position (P ₂) and cut-off the second transition label location (P between the position ₅) time, ratio V ₂/ V ₁By greater than 1 maximum,

Ratio V ₂/ V ₁Keep below 0.5 numerical value, as long as first contact device is at the 3rd transition label location (P ₇) and cut-off between the position wherein said the 3rd transition label location (P ₇) be positioned at the second transition label location (P ₅) and cut-off between the position.

2. according to claim 1ly be with charged air cock equipment, it is characterized in that the second transition label location (P ₅) occupy the transition separation point position (P of first and second starting the arc contactors ₃) and cut-off between the position.

3. each describedly is with charged air cock equipment according to aforementioned claim, it is characterized in that V ₂/ V ₁Maximum greater than 1.5.

4. according to claim 1 and 2ly be with charged air cock equipment, it is characterized in that the second permanent contact device (70) and second starting the arc contact device (72) engage each other securely.

5. according to claim 4ly be with charged air cock equipment, it is characterized in that:

First contact device (12) has mass M with blast pipe (16) formation ₁First mobile component;

The second permanent contact device (70) and second starting the arc contact device (72) formation have mass M ₂Second mobile component; And

When first contact device (12) passed through the first transition label location, velocity ratio had confirmed relational expression:

$0.8\frac{M_1}{M_2}\&le;\frac{V_2}{V_1}\&le;1.2\frac{M_1}{M_2}.$

6. according to claim 5ly be with charged air cock equipment, it is characterized in that, when first contact device during by the first transition label location, velocity ratio has confirmed relational expression:

$\frac{V_2}{V_1}=\frac{M_1}{M_2}.$

7. according to claim 1 and 2ly be with charged air cock equipment, it is characterized in that transmission mechanism (20) comprising:

Cam (184), it makes to pivot and comprise curve track (92) around the geometrical axis (89) fixing with respect to big envelope (10),

Slide block (90), it is engaged in second starting the arc contactor (72) securely and operates together in conjunction with track (92), and

Connecting rod (86), it is hinged on cam (84) and goes up and be engaged in securely on the hat seat (88) of blast pipe (16).

8. according to claim 1 and 2ly be with charged air cock equipment, it is characterized in that transmission mechanism comprises:

Cam (184), it makes to pivot and comprise first curve track (192a) and second curve track (192b) around the geometrical axis fixing with respect to big envelope,

First slide block (190a), it is engaged in second starting the arc contactor (72) securely and operates together in conjunction with first track (192a), and

Push and pull system, it is engaged in blast pipe (16) securely and comprises second slide block (190b) that operates together in conjunction with second track (192b).

9. according to claim 1 and 2ly be with charged air cock equipment, it is characterized in that, blast pipe comprises neck, for the air-flow that flows to the inboard gas allowance for expansion of big envelope (54) from electric arc expanded volume (48) constitutes first current path, this first path makes it closed by second starting the arc contactor (72) at least in part, so long as first contact device (12) is at make position and the 4th transition label location (P ₆) between, and the 4th transition label location (P ₆) be positioned at the transition separation point position (P of first and second starting the arc contactors ₃) and cut-off between the position.

10. according to claim 9ly be with charged air cock equipment, it is characterized in that this equipment comprises second current path (60), be used for the electric arc expanded volume (48) of big envelope (10) and the air-flow between the gas allowance for expansion (54).

11. according to claim 9ly be with charged air cock equipment, it is characterized in that second current path (60) is equipped with EGR Delay Valve (61), as long as first contact device (12) is at make position and the 5th transition label location (P ₄) between, and the 5th transition label location (P ₄) be positioned at the transition separation point position (P of first and second starting the arc contactors ₃) and cut-off between the position, this EGR Delay Valve promptly keeps sealing.

12. according to claim 11ly be with charged air cock equipment, it is characterized in that the 4th transition label location (P ₆) be positioned at the 5th transition label location (P ₄) and cut-off between the position.

13. according to claim 12ly be with charged air cock equipment, it is characterized in that the second transition label location (P ₅) approach the 4th transition label location (P ₆) and the 5th transition label location (P ₄).

14. according to claim 11ly be with charged air cock equipment, it is characterized in that first starting the arc contactor comprises socket, and current path be by this socket.

15. according to claim 14ly be with charged air cock equipment, it is characterized in that as long as first contact device is between the separation point position of the make position and first and second starting the arc contactors, second starting the arc contactor is just blocked socket.

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