EP0977234A2 - Trip device for a ground fault circuit breaker and circuit for controlling the same - Google Patents

Abstract

Circuit breaker has trip with magnetic drive arrangement. Area between yoke legs (12,14) has magnetic actuator (25) which has second permanent magnet (26) and coil (27). If faulty current occurs, extra coil impacts armature of trip. Bistable actuator is used as magnetic drive, providing sufficient energy to overcome adhesion force armature and pole surface.

Description

The invention relates to a tripping device for a residual current circuit breaker, according to the preamble of claim 1 and a circuit arrangement according to the preamble of claim 8.

A trigger, as is usually known, has a U-shaped yoke, the both legs are covered by a rotatable hinged anchor. On the yoke there is a permanent magnet that generates a magnetic flux inside the yoke, so that the hinged anchor is tightened. The hinged anchor is under the force a spring that continuously acts on the hinged anchor in the opening direction, the magnetic attraction force is greater than the spring force. On one leg of the U-shaped A yoke is arranged in a coil connected to the secondary winding of a summation current transformer connected is; the fault current flowing through the coil generates a flow in the yoke that is opposite to the flow that comes from the permanent magnet is, so that the hinged anchor with sufficient flow compensation under the force of the spring is moved to the open position. This can result in unlatching the switchgear of the residual current circuit breaker.

There is the problem that between the hinged armature and the pole face, of that the hinged anchor moves away when triggered, can form an adhesive layer, so that the excess force of the spring is not sufficient to ensure the contact of the armature with the to solve the corresponding pole face; in this case the trigger and personal protection fail cannot be guaranteed.

To avoid this possible failure of the mechanism, several are different Principles become known:

You can prevent the trigger from not firing if the functionality the trigger is checked at certain intervals. If the anchor of the pole face is subtracted in such a test case, then it is prevented that a harmful adhesive layer between the magnetically kept in contact Can form surfaces. A residual current circuit breaker has one for testing Test circuit with which a fault current is simulated. When pressing a test button trigger and switch off the residual current circuit breaker.

In addition, there are line-voltage-dependent and line-voltage-independent additional devices, who exert a force or a force impact on the anchor to Loosen adhesion; one can use piezoelectric actuators or actuators with shape memory alloy use.

With piezoelectric actuators there is the problem that due to the size electrical parameters to provide the mechanical power difficult to implement are. It would be a high number of primary windings and therefore an unacceptable one Frame size of the converter required; furthermore there is the problem that the Piezo actuator only executes a small stroke, so that a high precision in the adjustment the zero setting is required.

Actuators with shape memory alloys require energy in the form of heat by an ohmic consumer, if possible from the fault current, by one To achieve grid voltage independence must be generated. With the corresponding Frame sizes for residual current releases are those in the secondary circuit of the transformer available power too small to provide the actuator with a required Heat the mass in a sufficiently short time so that the Curie point is exceeded becomes. Actuators in which a shape memory alloy is used therefore normally heated depending on the mains voltage, with the problem that it in the event of an interruption, for example, of the neutral conductor or of the phase conductor of which the respective actuator takes its energy, can not be operated.

The object of the invention is a trigger device for a mains voltage independent To create residual current circuit breakers of the type mentioned with the the protective function is further improved. The required energy from the Residual current can be obtained, so that the triggering device without auxiliary energy, for example from the network. Furthermore, there is the object of the invention therein, a suitable circuit arrangement for controlling the triggering device to accomplish.

This object is achieved according to the invention by the features of claim 1.

According to the invention, the trigger is a magnetic drive arrangement with a another permanent magnet, another coil and one when a Fault current from the further coil by means of a spring force from a first position, in which it is not, in a second position in which it is the hinged anchor of the trigger opens, assigned to powered submersible anchor.

Such a magnetic drive arrangement is also referred to as a bistable actuator the invention makes use of the fact that such a bistable magnetic actuator can provide such energy that adhesive forces between the hinged anchor, also called anchor for short, and the neighboring pole face can be overcome can.

According to a special embodiment of the invention, a attack the second spring that acts on the submersible anchor in the opening direction of the hinged anchor. There is a possibility that the magnetic drive arrangement only has a winding.

The plunger anchor suitably carries a pin made of non-magnetic Material with which the submersible anchor hits the side of the folding anchor over which the The armature support surface is detached from the pole surface.

According to one embodiment of the invention, the magnetic drive arrangement between the yoke legs of the magnetic yoke of the trigger and between the web of the magnetic yoke and the folding anchor.

According to a further, particularly expedient embodiment, the magnetic drive arrangement be attached to the side of the trigger and by means of a laterally projecting one Act lever arrangement on the hinged anchor. This ensures that this additional magnetic drive arrangement as an additional device for a trigger can be attached to any commercially available trigger.

The resetting of the magnetic drive arrangement is then also according to the invention at the same time as the folding anchor is reset.

A circuit arrangement for controlling the magnetic drive arrangement is the claim 8 can be seen.

Such a circuit arrangement has a total current transformer through which Mains are passed through, and a secondary winding, the connections with the Coil of the trigger are connected; According to the invention, an energy store can be provided be charged by the secondary fault current. The energy storage can then be discharged via the winding of the magnetic drive arrangement.

When a certain threshold value or State of charge or only time-controlled unloading.

Further advantageous refinements and improvements of the invention are the see further subclaims.

Using the drawing, in which some embodiments of the invention are shown are, the invention and other advantageous refinements and improvements the invention are explained and described in more detail.

Fig. 1

eine Seitenansicht einer Auslöseeinrichtung mit einem zugeordneten Aktor,

Fig. 2

eine erste Ausführungsform einer Schaltungsanordnung zur Ansteuerung des Aktors,

Fig. 3

eine weitere Ausführungsform zur Ansteuerung des Aktors, und

Fig. 4 und 5

den Aktor in zwei Stellungen.

Show it:

Fig. 1

a side view of a triggering device with an associated actuator,

Fig. 2

1 a first embodiment of a circuit arrangement for controlling the actuator,

Fig. 3

a further embodiment for controlling the actuator, and

4 and 5

the actuator in two positions.

Fig. 1 contains the representation of a known trigger 10, which is a U-shaped Yoke 11 has a permanent magnet 13 on one leg 12 thereof is fixed, whereas the other leg 14 carries a coil 15, the coil connections 16 and 17 with the secondary winding of the total current transformer of a residual current circuit breaker (see below).

The two legs 12 and 14 have pole faces 18 and 19, which are covered by a hinged armature 20 which is rotatably mounted on the leg 12 and projects beyond this leg 12 with an extension 21; on a further extension 22, which is used to fix the permanent magnet 13 to the leg 12, and on the extension 21 a tension spring 23 is attached, which acts continuously on the hinged armature 20 in the direction of arrow P ₁ , so that it removes the hinged armature 20 from the pole face 19 tries to withdraw.

The permanent magnet generates a magnetic flux within the yoke and the hinged armature, which together form a closed magnetic circuit, which attracts the hinged armature 20 against the yoke surface 19. In the event of a fault current, the coil 15 generates an opposing magnetic flux, so that the attractive force of the pole face 19 on the hinged armature 20 is reduced until the spring force of the spring 23 predominates and the hinged armature opens in the direction of arrow P ₁ .

Up to this point, the trigger 10 is state of the art.

In the area between the two legs 12 and 14, the trigger 10 is a magnetic Assigned actuator, which is shown in more detail in FIGS. 4 and 5. This magnetic Actuator, which has the reference number 25 in its entirety, as below to be explained in more detail, a second permanent magnet 26 and a second Coil 27; the ends of the winding of the coil 27 are designated by the reference numerals 28 and 29 and are in a manner shown below with the secondary winding connected as well as connections 16 and 17.

Reference is now made to FIGS. 4 and 5. These show the electromagnetic Drive system 25, 26, 27 (see Fig. 1).

The electromagnetic drive or armature system, i.e. the trigger, has a closed one Yoke 40 with a lower web 41 and an upper web 42, which means Central webs 43 and 44 are connected to one another, so that a closed Magnetic circuit is formed. There is a possibility that the webs 41 and 42 circular plate and the webs 43/44 are formed by a cylindrical shape. Within the webs 43 and 44 or the circular cylinder pot there is a coil 45, which surrounds a plunger anchor 46 and is located near the lower web. Directly a permanent magnet arrangement 47 is provided after the coil 45, which is either formed by two permanent magnet parts. Instead of two permanent magnet parts an annular plate could also be provided. The Submersible anchor 46 slides within the permanent magnet assembly 47. The free end of the plunger anchor 46 carries a pin 48 made of magnetically insulating material which reaches through an opening 49 in the upper web. Between the diving anchor 46 and the inner surface of the web 42 is a spring 50 is arranged, which with one End on the immersion anchor 46 and the other end on the inner surface of the web 42 is attached. The ends of the coil winding of the coil 45 have the reference numbers 51 and 52.

Fig. 4 shows the arrangement 40 in the form in which the plunger 46 against the lower web 41 abuts. Here, due to the permanent magnet arrangement 47 Magnetic flux 53 generated, on the one hand by the plunger 46, the web arrangement 43, 44 and the lower plate 41 passes through. The spring 50 is so between the upper plate 42 and the plunger 46 arranged to the Submersible anchor 46 is continuously loaded in the direction of arrow P. However, the plunger anchor is 46 due to the flux 53 coming from the permanent magnet arrangement 47 below attracted to the web 41 or the plate 41. In this case the pin is located 48 with its free end within the top plate 42 or at least its free one End flush with the outer surface of plate 42.

The hinged armature 20 or one attached to it is located above the magnet arrangement 40 fixed lever, e.g. B. at a distance from the upper plate 42 and thus in one Distance from the free end of the pin 48 in the order of 1 mm.

If a fault current occurs, it flows via the terminals 51 and 52 through the coil 45, whereby a magnetic flux is generated within the magnet system 40, which flows through the permanent magnet arrangement 47, the webs 43, 44, the plunger 46 and the upper plate 42 extends, whereby the attractive force of the lower plate 41 or the magnet assembly 40 on the plunger armature 46 is released and the plunger armature 46 is moved upwards by the spring force of the spring 50, so that the plunger armature 46 strikes against the inner surface of the upper plate 42 and the Pin 48 against the hinged anchor 20, so that the hinged anchor 20 is pivoted in the direction of arrow P ₁ (see FIG. 1), whereby any adhesive forces present between the yoke surface 19 and the anchor 20 are overcome. As soon as the fault current is switched off, the plunger armature 46 is brought mechanically back into the position according to FIG. 4.

The magnet arrangement shown in FIGS. 4 and 5, ie the actuator, can now be used in addition the trigger 10 may be arranged so that the an independent, separate, in addition attachable part. There is of course also the possibility, as indicated in FIG. 1, that the actuator is arranged within the yoke; this of course depends on the size of the actuator.

2 shows a first embodiment of a control for the magnetic arrangement 4 and 5.

The network conductor R and, if appropriate, the network conductors S and T and a neutral conductor N shown in broken lines are passed through a toroidal core converter 60 as the primary winding. A secondary winding 61 is wound around the toroidal core converter 60, which is connected to the coil 15 of the release (see FIG. 1), a coupling coil 62 being provided which is connected to a circuit arrangement for controlling the winding 45. The coupling coil 62 is guided to a delay switching device 63 which closes a switch 64 with a delay of less than 50 ms, a rectifier 65 being connected between the one end of the coupling coil 62 and the switch 64, a voltage U _{c being} present between its output terminals is. A capacitor 66 is connected in parallel with the rectifier 65; In parallel to the capacitance 66 there is an integrated circuit 67 which controls a switch 68 which is located in a parallel line 69 in which the coil 45 is located. A diode 70 is located between one end of the capacitor and the integrated control circuit 67; a further diode 71 in parallel with the coil 45.

The switch 64, which is also referred to as a delay switch, is an on switch and is accordingly arranged on the secondary side in front of the rectifier 65. When the switch 64 has switched through, the voltage U _c at the output of the rectifier or at the capacitor 66 increases with the charging of the capacitance 66 by the charging current I _c. The integrated circuit or the electronic component 67 ensures that the switch 64 is opened , whereas the switch 68, which is preferably a MOSFET or a microthyristor, is closed as soon as the desired capacitor voltage U _c0 has been reached. As a result, the capacitor is discharged via the coil 45 and the diode 70, so that the magnet system is moved from the position shown in FIG. 4 to the position shown in FIG. 5.

The circuit arrangement according to FIG. 3 is similar to that of FIG. 2. On the secondary winding 61 is the coil 15 of the trigger and between the secondary winding 61 and the coil 15 there is a changeover switch 72 which, from a first position, in which the secondary winding 61 is connected to the trigger coil in a second position is switched so that electrical current from the secondary winding 61 can flow to a connection point 73, which is connected to a transformer 74 whose secondary side 75 is connected to the rectifier 65; the rest The arrangement of FIG. 3 corresponds to that of FIG. 2.

As you can see, the inductive decoupling or a voltage transformation takes place in two ways, namely with a coupling coil on the release core or the yoke 1 and by switching the trigger circuit from Trigger on a separate transformer, which bears the reference number 74 in FIG. 3.

The advantage of the second circuit arrangement according to FIG. 3 is that Turns ratio can be selected independently of the trip coil; Indeed a separate transformer core must be added as a component.

The magnet arrangements according to FIGS. 4 and 5 are in the trigger according to FIG. 1 installed, the arrangement between the two legs 12 and 14 to lie is coming. This causes a direct transmission of impulses to the hinged anchor 20. The actuator can of course also be provided outside the release lever, in which case an in The lever reaching into the trigger area transfers the force to the hinged anchor accomplished.

The return of the extended middle leg can be done mechanically with the closing of the armature caused by the switching mechanism. To 1, a reset mandrel 81 is fastened to the armature 20 by means of a spring 80, which can reach through a recess 82 in the hinged anchor 20 and against the pin 48 comes to rest when closing and the plunger anchor over presses the pin inwards against the lower plate 41. In this case the Force effect of the magnetic flux in the lower part of the actuator core is the spring force of the spring 50 and the plunger anchor is held in the lower end position according to FIG. 4.

The main advantages of this arrangement are as follows: In contrast high voltages are not required for a piezoelectric actuator and it no unused capacity needs to be charged. The currents for the operation of the actuator are small, so that no mains voltage for recharging the energy store is needed. Furthermore, a magnetic actuator, as z. B. in Figs. 4 and 5 is shown by way of example, movements in the millimeter range without problems carry out so that a sufficiently low adjustment accuracy is required. in the In contrast to the shape memory-based actuator, no heat capacity has to be charged so that neither a high current nor a long time is required. It is just to generate a current surge that the flow compensation in the actuator for about 10 ms Can allow 30 ms. With the available low current level the energy buffer in the form of capacitor 66 must be used become; however, capacitance and voltage values are not critical here.

Due to the delay device in the delay switch 63/64 or 72 the magnet system, d. H. 4 and 5 only after an adjustable Delay time activated; if the trigger function is normal, it comes therefore no action, since then the fault current is switched off, the capacitor 66 would charge. However, if the solution should fail, for example if the hinged anchor is not pulled off the yoke or the yoke surface 19, d. H. so the contact pieces of the residual current circuit breaker remain closed, then flows even after an adjustable delay time, the fault current still and therefore also the transformed current on the secondary side of the converter, d. H. in the secondary winding 61, whereby the magnet arrangement according to FIGS. 4 and 5 are activated can. The fault current on the secondary side is such that the one within the circuit arrangement electrical components located are easily supplied can.

Claims (16)

Tripping device for a residual current circuit breaker, with a permanent magnet generating a yoke, a first magnetic flux in the yoke, an armature and a coil which generates a second magnetic flux opposite to the first magnetic flux when a residual current occurs in the yoke, so that a to the The yoke, which is attracted by the first magnetic flux, is pulled off the yoke by the force of a first spring and thereby unlocks a switching lock having a trigger, characterized in that the trigger has a magnetic drive arrangement with a further permanent magnet, a further coil and, if a fault current occurs, from the another coil by means of a spring force by means of a first position, in which not, in a second position, in which it opens the hinged armature of the trigger, is assigned a driven plunger. Tripping device according to claim 1, characterized in that on A second spring engages the plunger in the opening direction of the Hinged anchor applied. Tripping device according to one of claims 1 and 2, characterized in that that the magnetic drive arrangement has only one winding. Tripping device according to one of the preceding claims, characterized in that that the plunger carries a pin made of non-magnetic material with which the submersible anchor hits on the side of the hinged anchor over which the detachment the armature contact surface takes place from the pole surface. Tripping device according to one of the preceding claims, characterized in that that the magnetic drive arrangement between the yoke legs of the magnetic yoke the trigger and arranged between the web of the yoke and the hinged anchor is. Tripping device according to one of claims 1 to 4, characterized in that that the magnetic drive assembly is attached to the side of the trigger and by means of a laterally projecting lever arrangement acts on the hinged anchor. Tripping device according to one of the preceding claims, characterized in that that the reset of the magnetic drive assembly at the same time The hinged anchor is reset. Circuit arrangement for controlling the triggering device according to one of the previous claims, with a summation current transformer, passed through the network conductor are, and with a secondary winding whose connections to the coil of the trigger are connected, characterized in that an energy store is provided is that is chargeable from the secondary fault current, and that the Energy storage can be discharged via the winding of the magnetic drive arrangement. Circuit arrangement according to claim 8, characterized in that the Energy storage can be discharged when a certain threshold value is reached. Circuit arrangement according to claim 8, characterized in that the Energy storage can be discharged after a certain period of time. Circuit arrangement according to claim 8 to 10, characterized in that a rectifier is provided in front of the energy store, the rectifier Rectified fault current. Circuit arrangement according to one of claims 8 to 11, characterized in that a coupling coil is arranged on the trigger, the output of which Rectifier is connected. Circuit arrangement according to claim 12, characterized in that between the coupling coil and the rectifier arranged a delay circuit is, so that the coupling coil current with a time delay of <50 ms Rectifier can be fed. Circuit arrangement according to one of the preceding claims 8 to 13, characterized characterized in that a transformer is provided in parallel with the trip coil is whose secondary side is connected to the rectifier, and that between Tripping coil and transformer a switch is provided, which within a Delay time <50 ms the secondary fault current of the primary side of the Feeds transformer. Circuit arrangement according to one of claims 8 to 14, characterized in that that preferably a semiconductor switch is provided as the threshold switch is that of a component which detects the state of charge of the energy store is controllable. Circuit arrangement according to claim 15, characterized in that the controllable switch is a thyristor, Mosfet or IGBT.

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