SU1233063A1 - Apparatus for synthetic testing of alternating current switch for breaking capacity - Google Patents

Abstract

The invention relates to the field of electrical engineering and can be used for synthetic tests (ta breaking capacity of high-voltage AC switches with several half-periods of arc time. The purpose of the invention is to increase the reliability of control, achieved by increasing the equivalence of short-circuit tests by creating a test switch of alternating current in the direction of a large test current. For this, an additional lock 7 was inserted into the device, breaker 8, unit 12 extending arc time and an additional inductive energy storage 13. In addition, the device contains a source 1 of direct current, an inductive tip energy -: 2, a switch 3, auxiliary inductor A, disconnecting element 5, high voltage circuit 6, unit 9 of the fop of the repair nanografiya, conclusions 10 and 11 for connecting the tested switch 2 ill. with s W N5 C 00 o C 5 00 ./

Description

one

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The invention relates to electrical equipment and can be used for synthetic tests on the outage ability of high-voltage AC high-current circuit breakers with several half-periods and arc time.

The purpose of the invention is to increase the control verification at the expense of increasing the equivalence of testing in short circuit conditions by creating an alternating in the direction of a large test current in the test switch.

Fig, 1 shows the proposed device; Fig. 2 shows timing diagrams of currents and voltages at the circuit breaker under test.

The device contains a source of direct current 1, an inductive energy storage device 2 and a switch 3 in series, in parallel with which auxiliary inductor 4 inductance connected in series, disconnecting element 5, high voltage circuit 6, an additional switch 7 connected in parallel are connected breaker 8. Parallel to the high voltage circuit 6, a recovery voltage generation unit 9 and terminals 10 and 11 are connected to connect the switch under test. The first output of the arc time extension unit 12 is connected to output 11 for connecting the test switch and the second output of the additional inductive energy storage 13, the first terminal of which is connected to the first output of the direct current source 1, and the second output of the arc burning time extension unit 12 with the common conclusion of the auxiliary coil 4 inductance and tripping element 5.

The device works as follows.

Before the start of the test, the switch-off element 5, the test switch and the breaker 8 are closed, and the switches 3 and 7 are open. After switching on the direct current source 1 through the inductive energy storage device 2, the auxiliary inductance coil 4, the disconnecting element 5, the test switch and the breaker 8 begins to leak current 14

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(FIG. 2), Odmovremenis m. starts to push current in price: direct current source 1, additional inductive energy storage 13, breaker 8. Energy accumulation occurs in inductive storage devices 2 and 3 and in the auxiliary inductor 4 . When the current reaches 14, the maximum value at

 A contact of the disconnecting element 5 and the test switch is opened and electric arcs arise between the contacts.

At time t, the contacts close.

5 tripping device 3, which shunts auxiliary inductance coil 4, tripping element 5, the subject

circuit breaker and breaker 8; The rate of decline of the current 14 in the test switch 20 body is determined by the equality

i.

where and and - (curve 15 in fig. 2) are the voltage drops on the arcs of the tripping element and the switch being tested - values almost constant at current 14 are greater than 3 kA;

L4 is the inductance value of the auxiliary inductance coil 4.

At the time t of the transition of current 14 through zero, the contacts of the breaker 8 are opened and an electric arc is lit between them. This causes a reduction and cessation of the current in the circuit from the additional inductive energy storage 13, the breaker 8 and the direct current source 1 and the appearance of current in the circuit consisting of the additional energy inductive storage 13, the test switch, the disconnecting element 5, the auxiliary coil

4 inductance, short circuit 3 and source 1 direct current. Thus, a current flows in the opposite direction through the test switch. In order to direct the energy of the additional inductive energy storage device 3 into the circuit with the test switch, it is necessary that the voltage drop on the arc is blurred, the cattle 8 exceeds the total voltage drop on the arcs in the disconnecting element 5 and the test switch approximately two times. The rate of increase of current 14 in the interval

where and. - voltage drop across the arc

in

unzipped about.

At time t, when the current through the breaker 8 is equal to zero and the arc in it goes out, the current 14 through the tested switch reaches its maximum value.

Taking into account that a direct current source 1 in the device has a low output voltage and this makes it possible to extinguish the arc prematurely in the test switch and disconnecting element 5 already at the first current crossing 14 through zero, the device uses an arc time extension 12, which instant t produces a rectangular current pulse with a duration of several hundreds of microseconds.

At the moment tI, the contacts of the additional switch 7, which bypasses the circuit consisting of the switch 3, the auxiliary inductor 4, the disconnecting element 5 and the switch being tested, are closed. Current 14 in the circuit breaker under test is reset again in accordance with expression (1).

The received current of industrial frequency in magnitude and direction in the tested switch provides the energy supply conditions kg arc of the tested switch in the same way as in the electrical network, in which

The second is a switch.

At time t, the preceding

the current 14 passes through zero, the high voltage circuit 6 is turned on with the current 16 of the above frequency, and since tg a current equal to the sum of the currents 14 and 16 flows through the switch under test and only the current 14 through the disconnecting element 5 disconnecting element 5 passes through zero (moment t) and the arc on it goes out, the test switch turns out to be switched on in high voltage circuit 6 and all further processes are determined only by the parameters of this circuit. After extinguishing the arc in the test switch (time t), its reset contacts

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The voltage 1b is applied, which is determined by the parameters of the high voltage circuit 6 and the regenerative voltage shaping unit 9.

All commutations are performed from the experience control device (not shown in Fig. 1), which is a timer that generates 1 {a sequence of control signals from the switching elements of the device and the test object in accordance with the timing diagram in Fig. 2.

Claims (1)

15 claims A device for synthetic testing of an alternating current switch for breaking capacity, containing a series-connected direct current source, an inductive energy storage device, an auxiliary inductance coil, a disconnecting element, leads for connecting a test switch in parallel with a high voltage circuit, and a restoring voltage shaping unit, The first output is connected to the common output of the inductive energy storage and auxiliary inductor. A circuit breaker, the second terminal of which is connected to the second output of a direct current source, characterized in that, in order to increase the reliability of control due to increased equivalence of tests in short circuits, an additional circuit breaker, a breaker, an arc time extension unit and an additional an inductive energy storage device, the first output of which is connected to the first output of a direct current source, the second output to the second output for connecting the tested switch and through steam an allele-connected additional contactor and a breaker are connected to the second output of a direct current source, and the first and second outputs of the arc burning time extension unit are connected to the second output of the additional inductive energy storage and the second output of the auxiliary inductor, respectively. t And FIG. 2