DE1249390B - - Google Patents

Description

JiiUTSCHES Wfl & vm ^ PATENT OFFICE

EDITORIAL

German class: 21 c - 68/50

Number: 1 249 390

File number: L 50532 VIII b / 21 c

I 249 390 filing date: April 22, 1965

Opened on: September 7, 1967

The additional patent application L 47068 (German Auslegeschrift 1239 389) relates to an arrangement to limit overcurrents, especially at the coupling point of high-voltage AC networks, as well as equalizing currents between networks in the event of a short circuit in one of these networks, or in the case of falling out of step, whereby a series connection of two reactances is inserted into the connection which have different signs and are approximately the same size in normal operation, and wherein the induction element of the series resonant circuit is provided with an iron core and the choke so is designed that at a predetermined overcurrent to be considered as a limit value, the iron core saturates, so that its reactance changes, with the impedance of the series resonant circuit increases, and suggests the inductive reactance from the parallel connection put together two chokes, one of which has a linear current dependence and the other has an approximately right-angled kinked current dependency.

When an overcurrent occurs, the voltage increases across the two chokes connected in parallel until the saturation voltage of the choke with the non-linear current dependency is reached is. Here the inductive reactance of this choke breaks down, so that the resonance with the series capacitance is disturbed and the entire series resonant circuit has a much higher total resistance having.

Reactors with non-linear characteristics can be uncontrollable in AC networks Vibrations, including higher frequencies, and tilting phenomena cause increased stress lead in the networks. Such phenomena are largely suppressed when according to the invention in the above-mentioned arrangement in series with the choke with the non-linear current dependency an ohmic resistor is connected.

This resistance is dimensioned appropriately when the non-linear choke becomes permeable to enable a sufficient detuning of the series resonant circuit, on the other hand an effective one To achieve damping of high-frequency vibrations and tilting.

This resistance can be provided for itself as a special element or in the throttle with the non-linear current dependency be incorporated, z. B. in the form of an additional winding Resistance wire or by making all or part of the winding Arrangement for limiting overcurrents

Addition to registration: L 47068 VIII b / 21 c -
Interpretation document 1 239 389

Applicant:

Licentia Patentverwaltungs-G. mb H.,
Frankfurt / M., Theodor-Stern-Kai 1

Named as inventor:

Dipl.-Ing. Hans Becker, Darmstadt

so resistance material. Other possibilities are also conceivable.

In the drawing, the circuit diagram of the invention is shown.

In normal operation, the capacitive reactance and the inductive reactance X _l consisting of the chokes Dr ₁ and Dr _{2 connected in} parallel are in resonance, so that only the unavoidable active losses in the line between the networks I and II are effective. The throttle Dr ₂ here has such a great resistance that according to the invention hardly any current flows through it and through the resistor R in series with it. If, however, when an overcurrent occurs, the voltage drop across the inductive reactance X _{1 reaches} the saturation voltage of the choke Dr ₂ , its reactance is reduced many times over, so that a large part of the current flows through it and the resistor. Here the resonance is disturbed, so that the resulting apparent reflection

\ o of the series circuit was effectively limiting the over-current is effected. The resistor R provided according to the invention attenuates the higher-frequency vibrations occurring when passing through the non-linear characteristic curve of the throttle Dr _{9 and avoids tilting phenomena in the circle.}

Claims (2)

Patent claims: 1. Arrangement to limit overcurrents, especially at the coupling point of High-voltage alternating current networks, as well as equalizing currents between networks in short- 709 640/420 final cases in one of these networks or when stepping outside, whereby in the connection a Series connection of two reactances is inserted, which have different signs and in normal operation have about the same size and where the induction member of the Series resonant circuit is provided with an iron core and the throttle is designed so that at a predetermined overcurrent to be considered as a limit value, the iron core is in saturation device, so that its reactance changes, with the impedance of the series resonant circuit increased and being the inductive Reactance consists of the parallel connection of two chokes, one of which is linear Current dependency and the other has an approximately right-angled current dependency, according to additional patent application L 47068 (German Auslegeschrift 1 239 389), characterized in that in series with the Throttle with the non-linear current dependency an ohmic resistance is connected. 2. Arrangement according to claim 1, characterized in that the ohmic resistance in the choke with the non-linear current dependence is accommodated. 1 sheet of drawings 709 640/420 8. 67 © Bundesdruckerei Berlin