DE1018504B - Potential control for switching sections of high-voltage switches - Google Patents

Description

For circuit breakers!], Especially those with multiple interruption points connected in series, it is due to the capacities to earth, that the spatial division over the opened Switching path becomes uneven.

There are potential controls become known, in which one in order to ensure an even distribution of the voltage To achieve a capacitance or an inductance or a resistance in parallel over the Sahalt section to the switching path.

The disadvantage of this arrangement is that via the branch connected in parallel after disconnection has taken place Currents of undesirable magnitude flow. These residual currents must, after that, the circuit breaker has switched off must be switched off by the isolating switches.

The invention provides a method of circulating these currents through a resonant circuit at operating frequency to disappear, but still maintain tension control.

According to the invention, such a potential control is achieved in that, according to the invention, a simultaneous parallel connection of capacitances and inductances is provided for switching paths of high-voltage switches with a dimension such that the capacitance formed by the capacitances and inductances connected in parallel and the capacitance given by the respective switching path The resonance frequency is equal to or approximately equal to the operating frequency. As a result, in addition to an even distribution of the voltage across the switching paths, after the switch has been switched off, a current flows through the control circuit which makes up only a fraction of the total current. A further capacitance and an inductance are connected in parallel to the capacitance formed by the respective switching path, the inductances lying parallel to the individual switching paths having ^{approximately the same effective resistance 1.}

The tuning of the resonance circuit to the operating frequency can also take place without taking into account the intrinsic capacitance of the switching path, if this Self-capacitance assumes such a value that it is hardly in relation to the parallel capacitance still causes an influence on the operating frequency tuning.

In the following, the invention is to be explained in more detail with reference to the schematic exemplary embodiments shown in the figures, but without this to want to restrict the invention to the exemplary embodiments.

In the embodiment shown in FIG. 1, a capacitor 11 and an inductance 12 are connected in parallel to each switching path 10. The out of potential control for switching sections
of high voltage switches

Applicant:

LICENTIA Patent-Verwaltungs-G.m.b.H., Hamburg 36, Hohe Bleichen 22

Dipl.-Ing. Guido de la Cerda, Frankfurt / M.,
has been named as the inventor

the capacitances 11 and the capacitance of the respective switching path 10 and the inductances 12 are formed Parallel circuits are tuned so that their resonance frequency is the same or approximately is equal to the operating frequency. This ensures that after the switch has been switched off, over a current flows in the parallel circuit, which is approximately equal to zero.

The potential-controlling function of the control circuit is not affected by the parallel resonance. However, the control device is also in the event of higher-frequency stresses via the Switching path (surge voltage, recovery voltage) fully functional. In these cases the resonance circuit is so detuned that the conductance of the inductance 12 compared to the conductance of the capacitors 11 can be neglected, so that the capacitors 11 take over the entire control function.

To with several inductors 12 for the dimensioning of one inductor 12 and one Capacitance 11 formed resonance circuit to allow a certain tolerance, the current resonance circuit be detuned at operating frequency in a range in which the resonance curve is already runs relatively flat, but the resonance circuit still has a sufficiently high impedance possesses, so that the residual flow remains in a negligibly small and permissible order of magnitude.

The effective resistance of the inductors 12 is expediently selected such that the course of the Resonance lamp when several are connected in series Current resonance circles remains approximately the same.

2 and 3 are two further exemplary embodiments of the potential control according to the invention shown, in which an inductance 13 or 14 is connected in parallel to a plurality of capacitors. In

709 758 / 3.17

In the exemplary embodiment shown in FIG. 2, there are two, in the exemplary embodiment shown in FIG. 3 four capacitors 11. The sizing and matching · of the capacitors and inductances formed current resonance circuits takes place in accordance with the explanations relating to the example shown in FIG. 1.

Claims (4)

Patent claims: 1. Potential control for switching sections of high-voltage switches with a uniform Distribution of the voltage across the switching paths, characterized in that a simultaneous Parallel connection of capacitances and inductances is provided from such a dimensioning, that by the capacitances and inductances connected in parallel and by the respective Switching path given capacitance formed resonance frequency equal to or approximately equal to the Operating frequency is. 2. Potential control according to claim 1, characterized in that when negligibly smaller Self-capacitance of the switching path the resonance frequency by dimensioning the parallel connected Capacities and inductances are formed. 3. Potential control according to claim 1 and 2, characterized in that the inductance is a or several switching paths is connected in parallel. 4. Potential control according to claim 1 or one of the following, characterized in that the inductances lying parallel to the individual switching paths have approximately the same effective resistance own. Considered publications:
Swiss patent specification No. 243 709,
708; British Patent No. 689,973. 1 sheet of drawings 709 758/317