SU864196A1 - Device for synthetic tests of switches for switchability - Google Patents

Description

The invention relates to electrical measuring technology and can be used to create dL devices for testing high-voltage switches for open / night capacity.

A device for testing high-voltage circuit breakers is known, which contains a low-voltage circuit and two test and auxiliary switches in series. A high recoverable voltage from precharged capacitors is supplied through a reactor whose inductance corresponds to the inductance of a short circuit in actual conditions tn.

The disadvantage of this device is that it is impossible to connect a charged capacitor at zero current in the switch being tested, which causes a delay in the voltage recovery and facilitates arc extinction in the switch.

The closest in technical essence to the invention is a device containing a low voltage circuit with two switches - a test subject and an auxiliary, shunt branch from

a capacitor and a resistor, and a voltage source, made on a capacitor, connected to a current and voltage recovery circuit, by a spark-gap, to an auxiliary switch via a G2 response.

The disadvantage of this device is the inability to provide

10 required conditions for extinguishing the arc to zero current in the tested switch, which reduces the reliability of the tests.

The aim of the invention is to increase the reliability of the tests.

15

The goal is to reach that in the device for synthetic testing of switches for breaking capacity, containing a low voltage circuit,

20 consisting of a low voltage source connected in series, a switching element, an auxiliary switch, clamps for connecting a test switch, the first high voltage source made on a capacitor and connected in parallel to the auxiliary switch through the first spark connection connected in series and the first reactor.

two circuits for adjusting the curve of the restoring voltage, each of which consists of a series-connected resistor and a capacitor, one of which is connected in parallel to the auxiliary switch, and the second is connected in parallel to the chain of series-connected auxiliary switch and terminals for connecting the switch to be tested, the second spark plug a second, a second high voltage source is introduced, made on a capacitor, a second reactor and a disconnecting element, the second source being Exposure to extreme voltage through the serially connected second spark arrester and a second reactor connected in parallel with the auxiliary switch, and the tripping element is connected between the second reactor and vspomogatelnlm switch. ,

FIG. 1 shows the electrical circuit, devices; in fig. 2 graphs of currents and voltages.

The device comprises a current loop with a low voltage source 1, a switching element 2, an auxiliary switch 3, clamps for connecting the test switch 4, the first high voltage source on the capacitor 5, the first spark gap b and the first reactor .7. Parallel to the auxiliary switch 3, a circuit is connected from the second high voltage source to the capacitor 8, the second spark gap 9, the second reactor 10, and the tripping element 11, made, for example, in the form of a fuse. In addition, the undervoltage circuit and the high voltage source contain circuits for adjusting the curve of the coax voltage, consisting of a resistor-12 and a capacitor 13, and a resistor 14 and a capacitor 15, connected in series, respectively.

The device works as follows.

At time t, the contacts of the switching on element 2 are closed and the current C of the industrial frequency starts to flow in the circuit of elements 1,2,3 and 4. At the moment of time t l the contacts of the auxiliary switch 3 and the test switch connected to the terminals 4 are opened.

At time t2, a spark 9 is triggered and a current of increased frequency IQ begins to flow in the circuit at elements 8.9, 10, 11, and 3, which in the switch 3 is superimposed on current c. ,

At the moment t f, the arc goes out in the test unit: the body, when the current passes through zero and from the side of the current circuit, the reduced voltage (curve 1, figure 2) begins to almost fully affect the test switch, since in the switch 3, the current i continues to flow.

At the same time, when current 1 approaches zero., Switch 3 does not affect arc extinction in the switch under test, since at time 1d the current i / j is not zero.

At time t, the arc in the switch 3 is extinguished when the current I passes through zero. At the moment tg, when the curve of the restoring voltage, determined by the current circuit, begins to deviate from the required voltage, the spark voltage 6 is triggered and the charged capacitor 5 is connected through the reactor 7 to the switch 3, bridged by a circuit from the resistor 14 and the capacitor 15, therefore A high voltage is established on this switch (curve II, Fig. 2). At the same time, the required voltage, equal to the sum of the reducing undervoltage of the current loop and the high voltage on the auxiliary switch 3, is applied to the tested switch.

The disconnecting element 11 is triggered at the moment Ls-at the zero crossing i., As a result, the circuit from the capacitor 8 and the reactor 10 separates from the switch 3, and thereby prevents the branch from affecting the voltage curve on the switch 3, and therefore on the test switch.

Claims (2)

1. Device for testing synthetic switches for breaking capacity, containing a low voltage circuit, consisting of a successively connected low voltage source, including an auxiliary switch element, clamps for connecting a test switch, the first high voltage source made on a capacitor and connected in parallel with the auxiliary switch, through the first spark discharge connected in series and the first reactor, two circuits to regulate a voltage recovery curve, each of which consists of a series-connected resistor and a capacitor, one of which is connected in parallel to the auxiliary switch, and the second is connected in parallel to the circuit from the series-connected auxiliary switch and terminals for connecting the test switch, the second spark, O T and what is it so with In order to increase the reliability of the test, a second high voltage source was introduced into it, made of a capacitor, a second reactor and a switch off element, the second high voltage source being connected through the second spark discharge and the second reactor connected in series a switch, and a disconnecting element is connected between the second reactor and the auxiliary switch. - Sources of information taken into account during the examination 1. Authors certificate of the USSR 86166 / cl. G 01 R 31/02, L947. 2. The patent of Germany 1180841, cl. G 01 R 31/14, 1964 (prototype).