Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
  • H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
  • H01H33/66—Vacuum switches
  • H01H33/666—Operating arrangements
  • H01H33/6661—Combination with other type of switch, e.g. for load break switches

Definitions

• the invention relates to the field of electrical equipment equipping the energy evacuation devices of alternators in power generation plants.
• the invention relates to the arrangement of the different breaking elements so that the generator circuit breakers are of more compact structure.
• the invention relates to an alternator circuit breaker coupled to a disconnector in which the different relative movements between contacts are on axes or in intersecting planes.
• a safety option is to have a circuit breaker to isolate the circuit before the transformer connected to a power line.
• This type of switchgear under a voltage of the order of 15 kV to 36 kV, then performs the functions of passing strong permanent current (of the order of several thousand amperes) and breaking high fault current. (of the order of tens of thousands of amperes), while isolating the circuit.
• the cut is performed in two stages by two switches in parallel, one permitting the passage of permanent nominal current and the other ensuring the breaking of the current of short circuit, thus defining a "main circuit” and an "auxiliary circuit".
• the main circuit switch contacts for these alternator circuit breakers are large enough to withstand high nominal currents without overheating, and they define a relatively large volume.
• the cut-off switch conventionally comprises a bulb of small dimensions disposed inside this volume and comprising movable arcing contacts relative to each other, which in fact support only the breaking current of the breaker.
• the alternator circuit breaker also includes a disconnector, which has no breaking capacity: it opens only when the circuit breaker is open and therefore when the current no longer passes through the circuit.
• a plant disconnector circuit breaker is described for example in EP 0 877 405.
• the invention aims to make the alternator circuit breakers more compact while retaining their properties.
• the invention relates in one of its aspects to an alternator disconnecting circuit breaker comprising a switching switch, for example a circuit breaker, in parallel with a cut-off switch, for example a vacuum chamber, and a switch. section, advantageously in series with the cut-off switch; each of the switches comprises a pair of movable contacts relative to each other along a respective axis or by rotation around a pivot, for example by means of an actuating bar coupled to actuating means.
• the circuit breaker further comprises synchronization means making it possible, during a switching off, separating successively and in this order the contacts of the switching switch, then of the cut-off switch, then of the disconnector; preferably, the synchronization means also make it possible to successively close the contacts in the reverse order.
• the same control means comprise these synchronization means and allow, by a single command, the implementation of each of the elements.
• the axes of the switches are not parallel to each other.
• the contacts of each of the three switches are animated with a translational movement relative to a respective axis, two of the axes being secant, preferably with the breaking switch disposed at right angles by relative to the switch and the disconnect switch.
• the first and second switches comprise movable contacts in translation along intersecting axes, the contacts of the disconnector being able to move in the plane defined by them or in an orthogonal plane for example.
• the isolator switch is associated with an isolator, wholly or partially, to add an arc insertion function in series with the cutoff switch.
• the means synchronization are adapted so that the main contacts are first separated, and the disconnector is slightly open so that an arc occurs when opening the vacuum chamber that intervenes immediately.
• the isolator is then fully open: the isolator is present to protect the other parts of the electric arc.
• Figure 1 schematically illustrates the principle of breaking a circuit breaker according to the invention.
• Figure 2 shows a preferred embodiment of the circuit breaker according to the invention.
• FIGS. 3A to 3F illustrate a break sequence for an alternator circuit breaker according to another embodiment of the invention.
• Figure 4 shows an alternative to the embodiment of Figure 2.
• FIG. 1 The operating principle of a circuit breaker, and in particular of an alternator circuit breaker according to the invention, is shown diagrammatically in FIG. 1, with a main circuit in which an intensity Io near the rated current I, and an auxiliary circuit solicited for the short-circuit break.
• the passage of a current I with a rated current greater than several thousand amperes requires the use on the main circuit of a switch 10 whose contacts are particularly conductive, for example copper ; their breaking capacity is however limited because of the generation of electric arcs.
• a second switch 20 is connected in parallel with the first 10 in order to perform the actual cutoff function, the opening of the first switch 10 actually switching the current I of the main circuit on this auxiliary circuit; the contacts of this second switch 20, for example tungsten, are of limited performance with respect to the passage of the rated current I, but have a high breaking capacity.
• the functions of transmission of the permanent current and short circuit break are separated: in case of bias, the first switch 10 is first activated, the current I then completely passes through the auxiliary circuit and causes the opening the second switch 20 to obtain the cutoff function.
• a third switch 30 is then open: its function is mainly a safety function, its association on the auxiliary circuit to avoid a dielectric strength drop of the second switch 20 which could accidentally allow the passage of current in the branch associated.
• the disconnector 30 is first closed, then the switch 20, and finally the first switch 10.
• Each of the switches 10, 20, 30 comprises a pair of movable contacts relative to each other ; advantageously, the first contact 12, 22, 32 of each pair is fixed, and the second contact 14, 24, 34 is movable relative to the first. According to a first embodiment illustrated in FIG. 2, each of the movable contacts moves in translation along a respective axis AA, BB, CC.
• the first switch 10 may be of the gas type; it can also, especially if the nominal current is very high, itself be a switching device comprising two switches in parallel with each other.
• the first switch 10 is a switch in the air comprising a first tubular contact 12 in which can be inserted a second tubular contact 14 as well.
• the actuation of this first switch 10 can be carried out by any known means, in particular control means 40 activating an actuating bar 42 coupled to the movable contact 14 in translation.
• the second switch 20 may be a gas circuit breaker SF 6 type; preferably, since the current I - Io passing through it is weak in normal operation, it is a vacuum interrupter: this makes it possible to avoid the use of sulfur hexafluoride which does not fulfill all the criteria ecological, and reduces costs.
• the movable contact 24 of the second switch 20 is moved by means of an actuating bar 44 movable along the axis BB.
• the third switch 30 may, according to one embodiment, comprise a fixed contact 32 in which can be inserted another movable contact 34 along the axis CC opening / closing, the rod type.
• the rod 34 can be moved by means of a bar 46 in translation.
• the same control means Preferably, the same control means
• control means 40 allow the displacement of the first 14, second 24 and third 34 movable contacts.
• control means 40 are operatively connected to each of the actuators 42, 44, 46, and comprise synchronization means 50 for deferring the relative openings of the switches 10, 20, 30.
• each actuating bar 42, 44, 46 of this embodiment moves in translation and is integral with the same control means 40
• the three axes AA, BB, CC of opening / closing are not necessarily parallel, at least one being intersecting the first axis AA for example.
• the synchronization means 50 can thus for example comprise, on the actuating bar 42 of the first switch 10, a generally longitudinal groove 52 along the axis AA of the bar but comprising an oblique part, the groove being associated with a element of the lug type 54 secured to the second actuating bar 44, so that, at first, during the movement of the first moving contact 14, the position of the lug 54 remains stable, then, in a second step, the lug 54 is displaced so as to move the second mobile contact 24 away from the second fixed contact 22. It may be advantageous for the axes AA, CC of the switching switch 10 and of the disconnector 30 to be parallel, as illustrated in FIG. 2, but other options are possible, as described below.
• the synchronization means 50 may comprise a system similar to the previous one 52, 54 to delay the opening of the disconnector 30 with respect to the breaking switch 20; it is however preferable that the synchronization means 50 are directly associated between the first and third switches 10, 30.
• the synchronization means 50 comprise a lever arm 56 coupled to an end portion at the third movable contact 34 and the pivot axis is associated with a groove 58 located in the actuating bar 46 of the third switch 30: the actuating rods 42, 46 of the first and third switches 10, 30 are moved jointly by the actuating means 40, but a delay in the displacement of the third contact 34 is generated by the latency before the pivoting of the lever 56.
• Other actuation and synchronization solutions are of course conceivable.
• the section switch 30 ' can operate on another principle of the type "knife disconnector".
• the main switch 10 ' comprises two relatively translational movable contacts 12', 14 'disposed in an envelope such as a 200 mm diameter tube; in an operating position illustrated in FIG. 3A, the alternator current I 0 flows in this main circuit (see arrow).
• the two contacts 12 ', 14' separate: the operation is performed by means of a bar 42 '.
• the current I retains its main path, but an arc is formed, covering the distance between the two contacts 12 ', 14' of the switch 10 '; then, the interruption on the main circuit is completed ( Figure 3C), and the current flows only on the auxiliary circuit, the delay means 50 'having delayed the opening of the contacts 22', 24 'of the cutoff switch 20 '.
• the dielectric distance on the main circuit makes it possible to hold the transient recovery voltage, that is to say that the bar actuator 42 'moves about half of its total stroke before opening the vacuum chamber 20'.
• the two relatively moving contacts 22 ', 24' of the breaking chamber 20 ' move in translation along an axis orthogonal to the translation axis of the first switch 10': 3D figure.
• the switch 30 'section is not solicited by the delay means 50'.
• the fixed contact 32 'of the disconnector 30' is integral with the fixed contact 12 'of the first switch; the second contact 34 'of the disconnector 30' is relatively movable by pivoting about an axis 36 '.
• the actuating means 46 'of the contacts 32', 34 'of this switch 30' are integral with the first bar 42 '; Furthermore, at the pivot 36 ', the movable contact 34' comprises delay means 56 'in the form of a groove complementary to a lug of the actuating bar 46' but allowing relative movement before driving by the bar 46 'of the contact 34' in rotation about its axis 36 ': finally, as shown in Figure 3F, the section is completed.
• the disconnector 30 ' can also move in a "horizontal" plane, that is to say, in the frame shown, by pivoting about a parallel axis 36' at one of the translation axes of the contacts of the other two switches 10 ', 20'.
• the isolator 38 may be fixed or integral with the rod 34 of the disconnector 30; it allows to insert by the disconnector 30 an arc in series with the vacuum chamber 20 and to prevent it from degenerating to earth.
• the disconnector 30 is slightly open when the vacuum chamber 20 is opened, with the creation of an arc at its level once the main contacts 10 are separated.
• the vacuum chamber 20 is in this case less stressed, the insulator 34 to protect it, as well as the other parts of the circuit breaker, the electric arc.
• alternator disconnecting circuit breakers according to the invention thus benefit from a reduced length relative to their height, which has the effect of advantage of reducing the size of such circuit breakers for easier transport.

Landscapes

• High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
• Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
• Gas-Insulated Switchgears (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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Families Citing this family (23)

Family Cites Families (8)

• 2006
  • 2006-01-17 FR FR0650156A patent/FR2896336B1/fr not_active Expired - Fee Related
• 2007
  • 2007-01-15 US US12/161,314 patent/US8081407B2/en active Active
  • 2007-01-15 CN CN2007800032299A patent/CN101375360B/zh active Active
  • 2007-01-15 WO PCT/EP2007/050318 patent/WO2007110251A1/fr not_active Ceased
  • 2007-01-15 EP EP07726196A patent/EP1974363B1/de active Active

Non-Patent Citations (1)

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