DE481669C - Safety protection device for current transformers built into high voltage lines - Google Patents

Description

Safety protection device for built into high voltage lines Current transformers The ones built into high-voltage lines for the operating current precisely matched and dimensioned current transformers for supplying relays and measuring instruments and the like are very endangered by 'occurring short-circuit and overcurrents. Frequently The current coils of the current transformers explode as a result of the dynamic effect the short circuit or excess current, or they burn due to the strong heat development, smelled before the built-in security devices could go into action. the The consequence of this are further short and Earth faults with often extensive devastation. According to the invention now these Disadvantages - eliminated by having one in the power line in series with the primary winding the current transformer lying thermostat or electromagnet a shunt to Primary winding closes automatically in the event of overcurrent or short-circuit current and after it has stopped of the overcurrent or short-circuit current also opens again automatically.

This is relatively simple and particularly reliable with effective means an unconditional protection of the built in high voltage switchgear Apparatus achieved and an entirely automatic one influenced by the current itself Activity guaranteed. In the drawing, the invention is shown in schematic form explained in two exemplary embodiments.

Fig.r shows a converter for high operating currents, while Fig. - The contact or short-circuit device can be seen in the plan. Fig. 3 shows a converter for small operating currents. r is the known current transformer with the connection contacts or poles a, 3. The pole a is with the involvement of a elastic current loop, which expediently consists of laminated copper sheets, connected to the line section 5. The two ends of the loop are rigid and held immobile, and the lying on the line section 5 is through a Post insulator 5 'worn or screwed to another fixed point.

On the current loop d. is an advantageous knife-like contact piece 6 arranged, and opposite this is a contact block 7, which with the other Pole 3 of the current transformer or with the connecting line 8 connected there stands.

Due to the electrodynamic effect of a short-circuit or overcurrent, the current loop q. pressed apart, the contact 6 pushes joins the mating contact 7 and short-circuits the converter. The one through the contact device flowing current also causes the two Lateral tongues of the Contact block 7 tighten each other and firmly against the stepped in between Turn on current loop contact 6 so that a perfect current transfer is guaranteed is.

After the overcurrent has ceased, it is due to the elastic effect the current loop of contact 6 returns to its rest position and forces the operating current, to flow through the current transformer again. In the version shown in Fig. 3, which is particularly suitable for smaller current transformers, approximately up to 3o Amp. operating current, are the two contacts or poles 2, 3 of the converter i with an insulating piece g bridged, aul the opposite contact tongues 6 ', 7' are arranged, the with their ends with the converter poles 2, 3 and the power line sections 5, 8 in Connected. An electromagnet is expediently off on the contact tongue 6 ' Laminated iron sheet attached, between the poles of which an armature is rotatably arranged i st, the contact brush acting as a short-circuit bridge on an extension arm q. ' wearing.

The anchor is under the effect of a not further drawn Return spring that always brings him back and thus the extension arm and contact bridge q. ' puts in superscript.

The winding of the electromagnet io is switched on in the line section 5.

When overcurrents occur, the armature projections are in the pole shoes drawn in and thus the contact brushes q. ' on the contact tongues 6; 7 'pressed, which are now bridged and short-circuited. Is the electricity back on for If the transducer has dropped to a safe height, the anchor returns under the action the return spring returns to its rest position, lifting the contact brush q. ' high and the normal operating state in which the current flows through the converter, is made.

Of course, instead of Wandlee, you can also use all the others in high-voltage switchgear Equip built-in apparatus with the safety device. It doesn't matter at which point of the current path the safety device is switched on, the can of course, for example, also be built into the apparatus.

Claims (2)

PATENT CLAIMS: i. Safety protection device for in high voltage lines built-in current transformer, characterized in that one in the power line in series Thermostat or electromagnet lying with the primary winding of the current transformer a shunt to the primary winding in the event of an overcurrent or short-circuit current closes and automatically again after the overcurrent or short-circuit current has ceased opens. 2. Safety protection device for claim i, characterized in that that the thermostat (q.) one to one leg the movable short-circuit contact (6) forms the load-bearing loop, which makes the electrodynamic forces self-acting Closing the shunt to the primary winding of the converter can be used.