SU1418820A1 - D.c. switch - Google Patents

Abstract

This invention relates to high-voltage switching devices. The purpose of the invention is to increase the breaking capacity and reduce the weight and size parameters of the switch. When the power contacts 1 open, the key elements 8 and 4 are turned on. The discharge current of the capacitors 7 coincides with the direction of the switched off current and is opposite to the discharge current of the capacitor 3. Imposing the discharge current of the capacitors 7 on the contacts 1 leads to a decrease in the rate of current flow in the power contacts I through zero, which allows to increase the breaking capacity of the switch and reduce its weight and dimensions. 2 hp f-ly, 3 ill.

Description

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The isobregenic is related to electrical engineering, namely to switching and high voltage gparag / d, but it is designed to disconnect the current.

The goal you invent is to increase the breaking capacity of the DC breakers and reduce the mass-massage of the breaker,

FIG. A diagram of the proposed .BbiKj ii04a i ejm J in FIG. 2 - current curve through the power contact,

nd FIG.

one of the variants of the scheme

the switch.

The switch contains contacts and is connected in series with i TjM inductance coil 2 that holds a ferromagnetic core. In parallel, they connect a main bucket with a key element 4,:; reject: m can be, for example, a riHeNbQ: eg. Capacitor 3 is connected to the charging device 5. In the rum of this shunt chain & chagel there is a hundred chain shunting only the power contacts I and containing the dololite condensation Ijpix 6 and ijjieMtUiTbi inductance connected) 1b: with a key element 8. In the example, in the second chain there are ti ii.ji iiacKonbKO capacitors 6 of different 1, a capacitor and several coils: an inductive hopper, and so chosen that the form of the discharge current; is close. right, but the current magnitude of the blip to j Oky remagnetizing coil 1 :. Coordination: Ators 6 are charged from 3. Hdd11O1 to device 9, the floor is p-Ki. C ib icuTo ;; : h o provides charge K1 M -Atnsarjjijb b. opposite in .y charge of capacitor 3.

Switch off; paGi Tae-j next about paaot-,

With the active position, the current through the switch. B flows, for example, from left to right. Capacitor 3 is charged with a positive sign on the right facing, which is on the left,

For whom ciiJiOBbix contacts 1 between them occurs and give a. When they talk / w) to an arcing distance for key elements 4 and 8, they are controlled by a pulse that initiates the discharge of capacitors i and 6. At the same time, it drives the HaD discharge. VOKOB in the circuit of power contacts 1 proginally. The discharge current of the capacitor containing the capacitors 6 and the coil 7 and 1 of the inductance is selected directly from the overcurrent of the coil 2, and d / bar of the rectangular part of the discharge current of the capacitors b is not less than a quarter of the discharge period of the capacitor 3. In this case the total GOK through the power contacts 1 when it passes through the first zero will be closer to the ideal process when the ferromagnetic core ka-2 has the characteristic namag-1-h1; Bahia without hysteresis. The curve of the current through the power contacts 1 in this case is shown in FIG. 2, the curve represents the current when the switch does not have a second w-11 interrupting chain, and the curve b is when current is applied from the second chain. The overlap of the current leads to a shift of the total current upward, due to which Nry the current approaching current to zero decreases, which facilitates the process of 1H arc.

The second chain may have a different structure. For example, capacitors 6 and coils 7 can be connected to an artificial long line. The second circuit may also consist of a capacitor 6 and a discharge resistance 10 (Fig. 3). In this case, the ammeter of the discharge current of the capacitor 6 must be close to the magnetization reversal current of the coil 2, and the time constant of this bit pattern dka or more than a quarter of the period of discharge capacitor 3.

The circuit breaker may also have other modifications. For example (FIG. 3, the charging device may be one if the shunting chains are connected on those sides of capacitors 5 and 6 that have the same sign. In this case, the key elements A and 8 must also be on these sides. The charge of capacitors 6 in this case It is possible only when the position of the power contacts 1 is on. To reduce the initial growth rate of the restoring voltage and increase the breaking capacity, the power contacts 1 can be ground by a third chain containing a capacitor 11 (FIG. 3), however this chain has It should not contain switching devices. To damp the oscillations in the curve of the restoring voltage, a third chain may contain a damping resistor 12. Resistor 13 separates the first two circuits.

The application of current overlap from the second chain allows the current approach to zero speed to be reduced hundreds of times in comparison with the known circuit breaker. This will reduce the capacitor capacitance by a factor of 2-3 if the limit currents are switched off. At the same time, the arc will be quenched to the first zero current when a smaller current is switched off.

g

18820

a key element, at least one pre-charged additional capacitor, and restrictive elements according to the number of said additional capacitors, each of which is connected in series with a corresponding additional capacitor, and these series circuits are connected to the terminals of the power contact through the specified additional key element so that polarity The pre-charge of additional capacitors coincides with the polarity of the power supply.

ten

15

Claims (3)

1. A switch of direct current, containing a terminal for connecting a power source and a terminal for connecting a load, power contacts, an inductance coil, a main capacitor, a main key element and a charge block of the main capacitor, and an output for connecting a coil inductance , the power contacts and the output for connecting the load are connected in series, the main capacitor and the main key element are connected in series and connected in parallel to the circuit section of the series connected inductance coils and power contacts so that the polarity of the precharge of the main capacitor is opposite to the polarity of the power source, characterized in that, in order to increase the breaking capacity and reduce the weight and dimensions, an additional 2. The switch according to claim 1, wherein the inductance coils are used as said limiting elements. 3. The switch according to claim 1, which is based on the fact that, in order to ensure the charge of these additional capacitors from the charging unit of the main capacitor, a charging resistor is introduced into it, another resistor is used as a limiting element, one output The charging resistor is connected to the circuit between the specified additional key element and the series circuit from the additional capacitor and another resistor, the other output of the charging resistor is connected to the circuit between the main capacitor and the main key element that the said core and additional key elements are connected to different pins. go contact.