SU699595A1 - Discharger - Google Patents

Description

(54) DISCHARGE

one

The invention relates to the field of electrical engineering, namely, devices for protection against high voltage overvoltage.

A device is known for deeply limiting overvoltages in high-voltage networks, comprising blocks of spark gaps, shunted by resistors, current-limiting resistors, and auxiliary resistors connected in parallel by parts of blocks of spark gaps through switching elements 1.

The closest in technical terms to the proposed invention is a discharge containing / series-connected spark gaps and current-limiting resistors, high-resistance shunt Ts1 {e resistors connected in parallel to the specified spark gaps, a pulse voltage divider, made in the form of a chain, a successor of connected capacitors , the connection points of which are connected through communication resistors to the corresponding connection points of the spark gaps and the switching device connected arallelno at

measure one spark gap through the auxiliary resistor 2.

in this order, due to the resistors of the connection, the spark pulses are sequentially activated.

However, in such a scheme, the resistors of communication and insulation between the circuits of the capacitors and the spark gaps must be chosen from the condition of a brief increase in voltage, as the spark is broken, the output gaps to each of the communication resistors connecting the capacitor circuit With the next spark gap, the voltage of all the capacitors of the pierced part of the spark gaps is applied. Thus, almost the entire pre-breakdown voltage is applied to the last resistor during the breakdown of the discharger, while there is no voltage in the rest state.

This leads to the fact that the transverse insulation should be the same as the longitudinal one, which increases the size of the gap.

The purpose of the invention is to increase reliability and reduce size. This goal is achieved by the fact that the known armature is supplied with additional high-resistance resistors connected in series with each capacitor in the chain of a pulse voltage divider. FIG. 1 shows the principle on the scheme of the pre-attached bit; in fig. 2 is a variant of the discharge. With a uniform shunt circuit along the entire length of the discharge and current-limiting resistors distributed along the length of the discharge. The discharge consists of two parts 1 and 2, which can differ in the form of development of the breakdown (Fig.), If necessary, they can also differ in the structure of the circuit, which determines the distribution of voltage. Each part contains series-connected current-limiting resistors 3 and arc extinguishing spark gaps 4, combined into blocks of at least two successively included spark gaps. To align the voltage across the blocks of the spark gaps of the gaps 4, they are shunted by series-connected capacitors 5 of the pulse voltage divider. If the capacitive circuit is not enough to equalize the voltage of the industrial Frequency, the blocks of the spark gaps can be bridged by high impedance non-linear resistors 6. In some cases, the shunt gaps are active resistors may be needed to align the voltage across the spark gaps inside the unit. The discharge also contains a control device 7 for controlling the discharge characteristics consisting of a series-connected auxiliary resistor 8. and a switching device 9, for example, a controlled valve block or a controlled spark gap, or an electromagnetic, pneumatic, etc. . switching device A switching voltage dividers circuit includes connection resistors 10 connecting the blocks of spark gaps 4 (total discharge or part 1 of it) with common points of series-connected capacitors 5. It is advisable to connect the control device 7 at the beginning or end of a series p Yes, spark gaps, preferably in the unit at the lowest voltage relative to the grounded end of the discharge, if an external power source is used for the switching device 9 and, or external control circuits. This unit will be pissed at a low setpoint (mean breakdown voltage) of the arrester. The control device 7 is connected in parallel to such a part of the spark gap of the igniting unit / shunting of which with an auxiliary resistor 8 leads to the breakdown of unshunned spark gaps of this unit with a discharge voltage equal to a lower setpoint. Consistently with each capacitor 5 connected to the spark gaps 4 through a communication resistor 10, a limiting impulse auxiliary resistor 11 is switched on in order to facilitate the operation of the communication resistors 10. In the disconnected position of the switching device 9, the auxiliary resistor 8 is disconnected from the spark gaps 4 of the firing unit, The voltage across the spark gaps of this block is distributed almost evenly and the discharge voltage has an increased setting. When the switching device 9 is switched on, the resistor 8 shunts a part of the spark gap 4 of the power supply unit, almost the entire voltage of the capacitor 5 of this block is applied to the non-shunted part, this part is punctured at a low voltage on the discharge, the voltage is applied to the resistor 8 and causes a shunted breakdown spark gaps igniting block. In this case, the voltage of the charged capacitor 5 of the firing unit is applied to the coupling resistor 10 of this block, if the resistances 11 shown by the dotted line in figure 1 are absent, and adding to the voltage up to which the second capacitor 5 is charged causes breakdown of the spark gaps 4 second block. Now k. HCKpoBbnvi the sum of the voltages of the first, second and third capacitor will be applied to the intervals of the third block; after the breakdown of these spark gaps, the voltage increases on the next block, etc. A high-voltage wave running towards the high potential will cause a consistent triggering of the spark gaps until the total breakdown voltage of the spark gaps that have not been triggered (part 2 in Figs. 2 and 1) becomes equal to the voltage applied to the discharge voltage. at the time of the start of the breakdown applied to each of them, the voltage is close to the breakdown voltage. By-; This part 2 of the discharge can be performed without the communication resistors 10, as shown in Fig. 1. The impulse voltage applied to the coupling resistors 10 increases with distance from the ignition source.

block, so their number can not be large. If a limiting pulse current resistor 11 is connected in series with each capacitor 5 (FIG. 2 and dashed in FIG. 1), the voltage drop across these resistors will reduce the voltage on the communication resistors to a predetermined value sufficient for reliable spark gap sampling. This pattern may have

the entire shunt circuit is homogeneous (as

Fig. 2), which will allow to assemble a bit of standard elements; Parts 1 and 2 in this case will differ only in the form of development of the sample. With a uniform discharge shunt, when blocks or groups of blocks of spark gaps 4 are separated by current-limiting resistors 3 connected in series with them, it is advisable to include each capacitor 5 through resistors 10 and 11. parallel to the blocks of spark gaps and current-limiting resistors (FIG. 2), so that the breakdown of all spark gaps 4 remaining on the resistors 3, the voltage is distributed evenly across the capacitors 5. Part 1 should be performed in the same way in FIG. 1, if the spark gaps 4 are divided by the limiting, 1 and resistors 3,

A multiple decrease in the voltage to which the switching device 9 and the resistor 8 must be performed, as compared with the devices where the control device 7 is connected in parallel with the whole part 1 of the discharge, significantly simplifies their design. At the same time, such advantages of a valve switching device, for example, thyristor, are used more effectively, such as high speed and simplified programming of control of discharge characteristics. In case of using a switching device of the switch type, its speed can be improved by reducing the stroke of the moving contact.

By appropriate control of the switching device 9, it is possible to ensure the short duration of a high; or low installation; In the first case, the proposed gaps can be used for power transmissions with high values of

voltages, where, at the successive values of these voltages, a short-time increase in the damping voltage is required, or to reduce the regenerative voltage on the parallel-connected arrays, when a short-term increase in the setting of the part of the arrays is needed to alternately break the current. A short set point reduction up to the operating voltage and even lower may be necessary for the time of voltage recovery at the switch that turns off the short circuit of one of the branches of the extensive network, because at substations, at the points of the voltage discharge the voltage can be much less than on the line, and often fail to reach the normal breakdown voltage of the arrester,

The use of such arresters makes it possible to reduce the overvoltages in networks of higher voltage classes to 1.5 and even lower.

Claims (1)

1. USSR author's certificate No. 521624, class, H 01 T 3/00, 1972, 2, Swiss Patent 547565, cl, H, 01 T 5/04, 1973.