DE1590939C3 - Arrangement for the protection of the telecommunication cables against inductive influence of high voltage systems - Google Patents

Description

del the correct compensation voltage according to the influence can be assigned. However, the interference voltages and the same large compensation voltages still differ from each other in terms of their phase position, which results in has that residual stresses still occur, although they are mostly below the limit up to the induced Tensions are viewed as permissible, but which in some cases are still bothersome impact. In order to adapt the compensation voltages precisely to the interference voltages also in the phase position can also be used in the primary circuit, in the intermediate circuits or in the secondary circuits Capacitors must be switched on in parallel with the windings. In particular, with inductive parallel connection the additional transformer have a further winding, to which no reduction transformer, but a capacitor is connected is. If capacitors with variable capacitance are used, it is also possible to after installing the reduction transformer arrangement, an exact alignment of the phase position of the compensation voltages for the interference voltages.

Exemplary embodiments of arrangements according to the invention are shown in the figures. Included indicates

F i g. 1 shows an arrangement in which the primary coils of the partial reduction transformers are galvanically parallel are switched and

F i g. 2 shows an arrangement in which the primary coils of the partial reduction transformers are inductively parallel are switched.

In both figures, the conductor bundles are only simple to keep the representation clear Lines shown.

In the arrangement according to FIG. 1, the cable ends 4, 5 are each broken up into three conductor bundles 7, 8, 9 and T, 8 ', 9'. The number of conductor bundles depends of course on the total number of cores and more than three conductor bundles can be formed in cables with a high number of cores. Corresponding to the number of conductor bundles, three partial reduction transformers A, B and C are provided with the primary coils A ₁ , B ₁ , C ₁ , the iron cores A ₃ , B ₃ , C ₃ and the secondary coils A ₂ , B ₀ , C ₉ . The primary coils A ₁ , B ₁ , C ₁ are connected in parallel to one another in the cable sheath 6. As with the known reduction transformers, a replacement conductor can also be used instead of the cable jacket

ίο be, z. B. if the cable sheath alone as a result its high ohmic resistance is not suitable. For phase adjustment, the primary windings can be used in parallel a capacitor 10 may be provided, if necessary, provided that after the installation of the Arrangement a phase adjustment should be possible, a capacitor with variable capacitance.

In the arrangement according to FIG. 2, each of the cable ends 4, 5 is also broken up into three conductor bundles 7, 8, 9 or 7 ', 8', 9 '. In addition to the partial reduction transformers ^ 1, B, C , an intermediate transformer E is provided here. The primary winding E _{1 of} this transformer is switched into the cable jacket or its replacement conductor and the primary coils A ₁ , B ₁ , C _{1 of} the partial reduction transformers are connected to the secondary coils E _2. With this arrangement there are various possibilities for the phase adjustment. Either an optionally variable capacitor 12 can be provided parallel to the primary winding E ₁ or capacitors 13 can be connected in parallel to the windings A ₁ , B ₁ , C ₁ in each of the intermediate circuits. Another possibility finally arises when a capacitor 11 with a variable capacitance is connected to a secondary winding E _{2 that is} not required for connecting a reduction transformer. Here, too, when using capacitors with variable capacitance, it is possible to precisely match the phase position of the compensation voltage to the phase position of the interference voltage and thereby achieve a practically complete compensation of the interference voltages.

1 sheet of drawings

Claims (4)

Patent claims: 1. Arrangement to protect the telecommunication cables against inductive influences on high-voltage systems, by increasing the magnetic coupling between the cable jacket and the telecommunication wires by means of a reduction transformer the laying of a new cable at least the mean value of the cable length wound on the core When pupinization can be taken into account, a considerable enlargement also occurs here this mean value, which significantly impairs pupinization. The invention is based on the object of an arrangement for protecting the telecommunication cables against inductive influence on power systems gates, characterized in that
The cable is broken up into several wire bundles (7, 8, 9, T, 8 ', io by increasing the magnetic coupling between 9'), which are used as secondary windings (A ₂ , see the cable jacket and the telecommunication wires B. "Cy") To create iron cores (A ₃ , B ₃ , C ₃ ) of several reducers by means of reduction transformers, the düktiönstransformatoren (A, B, C) are laid as small as possible, low iron weight have their primary windings (A ₁ , B ₁ , C ₁ ) to each other and only slightly increase the electrical cable length, parallel to the cable sheath (6) or its replacement. This task is achieved in that the cable set conductors are connected. is resolved into several bundles, which are called secondary windings around the iron cores of several reduction transformers - hereinafter referred to as »partial reduc tion transformers "- are placed, 2. Arrangement according to claim 1, characterized in that the primary windings (A ₁ , B ₁ , C ₁ ) of the reduction transformers (A, B, C) on the secondary windings (E.,) of another 20 whose primary windings are connected in parallel to one another to the transformer (E) , whose cable sheath or its substitute conductor is connected to the primary winding (E ₁ ) to the cable sheath (6),
or whose substitute conductor is connected. So every reduction transformer is in several 3. Arrangement according to claim 1 or 2, divided there- rere partial reduction transformers, ent by characterized in that in the primary circuit, in 25 speaking of the division of the cable to be protected the intermediate circuits or in the secondary circuits in several bundles. Each partial reduction transforms additional, optionally changeable, mator can be compared to the known Capacitors (10, 12, 13) have a magnetic core in parallel with the reduction transformers Windings are switched on. lower iron volume and an increased 4. Arrangement according to claim 2, thereby obtaining 3 ° formation number. Since the partial reduction transform characterizes that the intermediate transformer (E) mators whose primary windings are parallel to each other be connected to the cable jacket or its replacement, all have the same structure, is the The length of the secondary windings is the same. This means that all the twin cores of the reduction transformer are electrically the same length, so that the pupinization, even with subsequent installation of such reduction transformers, is not disturbed. The effect such reduction transformers in the elimination It is known (German Auslegeschrift 1113 488), 4 ° supply or reduction of the interference voltage is Telecommunication cable against inductive influences of practically completely the same as when using one Protect high-voltage systems by using the reduction transformer of known design. A Telecommunication cores · together with the metallic further advantage of the subject matter of the invention lies Cable sheath or its suitable replacement in several ways that the individual transformers for a more secure Windings around a magnetic core are 45 measured and standard number of cores has an additional secondary winding (E ₂ ) to which an appropriately variable capacitor (11) is connected. the. These devices, known as reduction transformers, make the magnetic Coupling between the cable sheath and the telecommunication wires increases because of the sheath current Magnetic flux generated in the magnetic core generates a counter voltage in the telecommunication wires, which counteracts the interference voltages and compensates them or at least reduces them to a harmless one Depreciates value. These known reduction trans- can be made, while the known reduction transformers each have the number of cores of the Telecommunication cables to be protected had to be manufactured accordingly in one-off production. The primary windings of the reduction transformers can, if the transformation ratio is 1: 1 ■ is used, be connected galvanically in parallel. But they can also be connected inductively in parallel be provided by adding another transformer formators have, if it is in the cable with a high 55, its primary winding to the cable sheath or Number of cores are switched on, the disadvantage that the replacement conductor is connected and the several Has secondary windings to which the primary windings of the actual reduction transformer Secondary windings of these reduction transformers take up a very considerable amount of space therefore use relatively long wire lengths mators are connected. Through the corresponding must be wound, the lengths at the ^{6o corresponding} choice of the transmission ratio of the outer windings are considerably larger than the inner windings. Through this extension of the cable, which is different in size in the cores, the pupinization of the cable is disturbed. Additional Part reduction transformers and, if applicable of the transformer connected upstream of this, an optimal compensation can be achieved. It is also possible, partial reduction transformers Difficulties arise when such a ⁶ S has different transformation ratios, such as a compliance transformer to eliminate induction when the cores are influenced differently in a cable (e.g. for branches) with only one protective device for each core or each core bundle tive faults should be switched on retrospectively in a cable that has already been laid, because while with