SU741749A1 - Spark gap assembly - Google Patents

Description

This invention relates to the field of overvoltage protection of high voltage electrical installations. There is a known arrester having spark gaps shunted by equalizing resistors, some of which are shunted by a control sparking gap ij. In such a discharge, in addition to a decrease in the breakdown voltage of the block of sparks, the arcing capacity is increased. A gaiter is known, consisting of series-connected power sparks, gaps and connected to it through resistors of an auxiliary circuit, in which there is an ignition device, consisting of a parallel-connected resistor and a firing spark gap, connected in parallel to one of the power gaps 2. The disadvantage is The bottom is a frequent false alarm under adverse weather conditions due to the uneven distribution of voltage between the elements of the arrester. Also known is a gaiter in which the control spark gap in series with which the capacitance and inductance tuned into resonance are included, is connected parallel to the last spark gap t3. The closest of the known technical solutions to the invention is a block of spark gaps,. containing series-connected power spark gaps with ohmic and non-uniform capacitive shunt circuits, some of which between the midpoint and one of the terminals of the unit are shunted through parallel-connected coupling capacitor and the coupling resistor by firing spark gap 4. In the block, the breakdown voltage is uneven capacitive shunting in each pair of spark gaps and the use of a spark igniter for communication purposes. However, such a block of spark gaps, taken as a prototype, is characterized by an insufficient decrease in the magnitude of the breakdown voltage, the complexity of the circuit. The purpose of the invention is to improve the discharge characteristics by further reducing the penetration voltage.

block compared to the sum of the breakdown voltage of individual spark gaps and simplifying the block by reducing the number of different circuit elements.

This is achieved by the fact that in a block of spark gaps containing successively connected power spark gaps (at least six) with ohmic and non-uniform capacitive shuntring circuits, some of which between the midpoint and one of the terminals of the block are shunted through a parallel connected capacitor and a communication resistor the igniting spark gap, the capacitive shunt circuit is made in the form of capacitors, each of which -1 is connected between the midpoint of the block and the external output of the corresponding power spark except the extreme, and the ohmic shunt circuit is made in the form of uniform resistors connected in parallel to each spark gap.

The drawing shows a block breakdown control circuit for eight spark gaps.

The block contains power spark gaps 1–8, divided into two groups 1–4, 5–8, Conclusions of spark gaps 2–4 and gaps 6–8 are connected to the midpoint of the block with the help of capacitors 9–11 and capacitors 12–14 respectively. The capacitors of the capacitors 9-14 are at least one order of magnitude larger than the own capacity of the spark gaps. A portion of the spark gaps 1-4 is shunted by the clamping spark gap 1b through the parallel-connected coupling capacitor 16 and the coupling resistor 17. Spark gaps 1–8 are respectively shunted by uniform resistors 18–25.

In addition, resistors 26 and 27 and capacitors 28 and 29 are included, respectively, between the midpoint and each output of the unit.

Elok works as follows.

When pulsed, the ignition gap 15 is first punctured. The breakdown voltage of this gap is about 15–20% lower than the breakdown voltage of the spark gaps 1–8. Due to the large capacitance of the capacitor 16 of the communication circuit as compared with the capacity of the shunt capacitor 14, almost all the voltage acting between the terminals of the block is applied to the spark gap B, and the latter is punched. After the breakdown of the spark gap 8, all the voltage is applied to the spark gap 7, which also breaks through and the voltage is applied to

spark gap 6, etc., until the breakdown of all the intervals of this group is completed. Then, all the voltage acting between the poles of the unit is applied to the capacitor 16 and the resistor 17 of the coupling circuit, under the action of this voltage, a cascade breakdown of gaps 1,2,3 and 4 takes place in a similar order.

The number of spark gaps in the channel group can be increased to reduce the breakdown voltage of the block. Resistors 18-25 form a circuit of uniform active shunting during periods of voltage on arcs, and resistors 26, 27 and capacitors 28.29 form a circuit of single-sided activity AND uniform capacitive shunting until the moment of breakdown of the block

Cascade actuation occurs almost instantaneously or at least within a fraction of 1 µs. The breakdown voltage at both fields of the spark gaps practically does not depend on the rate of voltage rise in the range of pre-discharge times (2-10000 µs).

Studies conducted on a block of six to eight spark gaps showed that the breakdown voltage can be reduced by a factor of 2 and 4 times, respectively, against 2.5, which is obtained for the prototype at eight spark gaps.

Claims (3)

The block of spark gaps was tested in the series RG-400 dischargers. The formula of the invention A block of spark gaps containing successively connected power spark gaps with ohmic and heterogeneous capacitive shunt circuits, some of which between the midpoint and one of the terminals of the block are shunted through parallel connected coupling capacitor and resistor with a firing spark gap, different in that Capacitive shunt circuit is made in the form of capacitors, each of which is connected between the middle point of the unit and the external output, respectively except for the extreme, and the ohmic shunt circuit is made in the form of uniform resistors connected in parallel to each spark gap. Sources of information taken into account in the examination 1, US Patent No. 3515934, CL 315-36, 1970. 2 US patent No. 3731154, cl. 317-70, 1973, 3. US Patent No. 3,611,044, CL 317-70, 1971. 4, US Patent No. 3518492, cl.313-325, 1970 (prototype). /five go gp 22 gz g g5 / 7  T