SU528652A1 - Diff - Google Patents

Description

I

This invention relates to overvoltage protection devices in ultrahigh and ultrahigh voltage networks.

Known arresters containing series-connected current-limiting resistors and blocks of spark gaps, shunted by parallel-connected capacitors and resistors 1. Capacitors align the volt-second characteristic of the discharge in the region of small times. In this scheme, it is not possible to obtain a reduction in the pulse ratio, which in many cases may be desirable.

Dischargers are known that contain series-connected current-limiting resistors and spark gaps, some of which have inhomogeneous capacitive shunting, which effectively reduces the breakdown voltage during terrible impulses, but does not reduce the breakdown voltage at switching overvoltages 2.

The closest technical solution to this invention is a discharge containing series-connected pairs of current-limiting resistors and spark gaps, one part of these pairs is shunted by series-connected capacitors and resistors, and the second part is shunted by capacitors 3. This

allows to reduce the pulse coefficient in the microsecond range.

However, this scheme does not allow to obtain a volt-second characteristic such as a resopancap with a maximum in the time domain corresponding to the industrial frequency (i.e., at the operating voltage and quenching voltage) and with a sharp drop on either side of this range, i.e. This characteristic.

in which the reliability of the radar and the effectiveness of protection against switching overvoltages increase.

The purpose of the invention is to increase the reliability of the emulator and the effectiveness of protection.

This is achieved by the fact that in the proposed bit, additional resistors are connected in parallel with the second part of the indicated pairs of current-limiting resistors and spark gaps.

In addition, these spark gaps are made with a pulse coefficient less than one.

Such a self-sustaining discharge (without special control) reduces the breakdown

Claims (3)

the voltage during switching processes in the network and, accordingly, the breakdown voltage in the current quenching mode, and hence the reliability of the discharge, increases, and thus provides an increased protection zone for switching waves, accelerated discharge of the line into an automatic restart pause (AR) and therefore a deeper level of overvoltage limiting. The drawing shows a schematic electrical diagram of the proposed bit (for simplicity, only two pairs of spark gaps and non-linear resistors are shown). The arrester contains series-connected spark gaps 1 and 2, alternating with nonlinear resistors 3 and forming pairs 1-3 and 2-3 with them, shunted respectively by series-connected resistor 4 and capacitor 5 and in parallel with the connected capacitor 6 and additional resistor 7. between line 8 and ground 9. When subjected to switching overvoltage with a frequency higher than the working one, a greater part of the voltage is applied to the spark gaps 1 pa shunted in series by resis 4 and a capacitor 5. The breakdown of these gaps occurs at a comprehended value of the voltage applied to the discharge voltage: the decrease will be the greater, the higher the overvoltage frequency and the greater its amplitude, then the gaps shunted by parallel-connected additional resistor 7 and the capacitor 6. Since the spark gaps 1 of this part of the pair are affected by a steeper voltage pulse, their number can be increased if they are performed with a pulse ratio less than one, which allows ositelnoe increase blanking voltage arrester and its breakdown voltage at industrial frequency. When the idle line is disconnected, the larger part of the voltage remaining on line 8 will be applied to the spark gaps of 1 pairs shunted by the series-connected resistor 4 and the capacitor 5, and they will break through first when the voltage is lower than the worker, causing a breakdown of the other spark gaps. Due to this, the discharge of the line during the dead pause of the automatic reclosing is reduced, which reduces 5 10 15 20 25 30 35 40 45 50 overvoltage during reclosure by 20% with a corresponding decrease in the current limit loads for the discharge. When the discharge current flows, the shunt circuit is loaded by the voltage remaining on the current-limiting resistors, which is close in magnitude and shape to the restoring voltage. Therefore, the initial conditions of the transient shunt circuit will be close to the steady state, the transient process will be insignificant and will not lead to a decrease in the quenching voltage. A surge is advisable to deeply limit overvoltages in cases where increased demands are placed on the damping voltage or on the reliability of the surge, or, if necessary, to increase the effectiveness of protection by increasing the protective zone. Claim 1. An arrester containing series-connected pairs of current-limiting resistors and spark springs, one part of these pairs being shunted by series-connected capacitors and resistors, and the second part being shunted by capacitors, characterized in that in order to increase the reliability of the arrester and the effectiveness of protection , parallel to the second part of these pairs of current-limiting resistors and spark gaps, additional resistors are connected. 2. The discharge of claim 1, characterized in that said spark gaps are made with a pulse coefficient less than one. Sources of information taken into account during the examination: 1. D.V. Shishman, A.I. Bronfman, V.I. Pruzhinina, V.P. Savelyev “High-voltage valve arresters. Energie, L., 1971, p. 36. 2. D.V. Shishman, A.I. Bronfman, V.I. Pruzhinina, V.P. Saveliev “Valve arresters of high voltage. Energie, L., 1971, p. 35. 3. The patent of the Federal Republic of Germany 1286190, cl. 21 C72, published 02.01.69. (Prototype).