SU1094148A2 - Quick-acting switching device - Google Patents

Abstract

QUICK OPERATION SWITCHING DEVICE according to author. St. 731588, characterized in that,; in order to improve the weight and size characteristics, the control winding of the drive is equipped with a tap and a circuit of a series-connected thyristor and a capacitor is additionally introduced, through which the tap of the control winding of the drive is connected to the thyristor of the semiconductor element.

Description

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four

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 The invention relates to a pulsed technique and can be used in arresting hybrid switches and power switches.

According to the main author. St. No. 731588 known a high-speed switching device containing power contacts, a high-speed actuator for forced opening of contacts, the control winding of which is connected to a unit with a tripping impulse comprising a precharged capacitor and an electronic switch with a control unit, a semiconductor element connected parallel to the silo contacts and also a parallel circuit consisting of a control winding and a 1J tripping pulse shaping unit.

However, in this device, the capacitance of the capacitor entering the tripping pulse shaping unit must be chosen from the following two conditions: the opening of the contacts for a distance XD ,, providing the necessary electrical strength, must occur within the required time determined by the speed of the device during the opening time contacts for a distance of XVVHH the capacitor discharge current must exceed the disconnect current. The capacitance of a capacitor, determined from the second condition, depends on the magnitude of the current to be shut off and in a number of cases it significantly presses the capacitance determined from the first condition, therefore at large values of the disconnected current, the capacitor capacitance is considerable, which increases the size, mass and cost of the device.

The aim of the invention is to improve the weight and size characteristics of the device.

This goal is achieved by the fact that in a switching device with a fast action / containing power contacts, a high-speed forced opening contact, the control winding of which is connected to a disconnecting impulse forming unit including a precharged capacitor and an electronic switch with a control unit, a semiconductor element connected parcel power contacts, as well as a parallel circuit consisting of a control winding and a tripping pulse shaping unit the drive winding is provided with a tap and an additional circuit is introduced from a series-connected thyristor and a capacitor through which the tap of the drive control winding. connected to a thyristor semiconductor element.

The drawing shows an example of a circuit diagram of a device for turning off direct current.

The switching device contains power contacts 1, a high-speed actuator for forced opening of contacts with control winding 2, shunt power contacts semiconductor element made in the form of parallel-connected thyristor 3 and diode 4 connected parallel to thyristor 3, a circuit consisting of a series-connected winding 2 of the switch commuting thyristor 5 and switching capacitor 6, forming a tripping pulse forming unit, an additional circuit of series-connected tees stories 7 and capacitor 8, 9 Block charge capacitors b and 8 and the control unit 10. The winding 2 is equipped with a tap 11 which is connected to the thyristor 3 through an additional circuit of a series-connected thyristor 7 and a capacitor 8.

The device works as follows.

In the on state, the capacitors b and 8 are charged from block 9 to the rated voltage with polarity indicated on the drawing. Unit 10 does not issue control signals, and thyristors 3, 5 and 7 are locked. When a trip signal is applied to the input of block 10, control signals are issued to thyristors 3 and 5. Discharge of capacitor b occurs through all turns of winding 2 and contacts 1, as a result of which the contacts open. In this case, the short-circuit current of contacts 1 flows into the thyristor 3 and the opening of contacts 1 takes place almost without arc, since the voltage drop on the open thyristor 3 is less than the minimum arc burning voltage.

Block 10 with a constant time delay, ut, which is performed, for example, on the basis of various one-shot schemes. control signal to the thyristor 7 and the removal of the signal from the thyristor 3. Exposure time

Lt is determined from the condition that the contacts 1 differ from each other by a distance that provides the necessary electrical strength when the voltage is restored (n1) is actually no less than 1 mm at 1000 V) with the worst running tolerances of the drive and the minimum voltage on the capacitor b.

The capacitance of the capacitor 8 and the number of turns of the outlet from the winding 2 are chosen such that the time during which the total discharge current i i, + i is greater than the maximum possible current of the network 1 is equal to time 310941484

switching off the thyristor 3. In this case, parallel to the power contact, ij creates additional 1 in the drive through the rectifying bridge I9

THERMAL POWER, provided with four diodes.

solution of disconnected contacts 1. Technical and economic effect of

In the disconnected state, the contacts of the invention consists of

are held by a latch or other that when switching currents,

mechanism exceeding 100-250 A, decreases

Is the total "bone of capacitors and

To switch the current to the Ostrodey, mass-circulating switches and switching characteristics of the device are correspondingly improved. AC power supply, pre-example, with switching current

assigned for operation in networks with Z-1000 A, the total capacitance of the condensate-earth neutral, from the circuit of a type K75-17 decreases more

It is diode 4, and thyristor 3 is doubled.

Claims (1)

FAST SWITCHING DEVICE for ed. St. No. 731588, characterized in that,; in order to improve the overall dimensions, the control winding of the drive is equipped with a tap and an additional circuit is introduced from series-connected thyristor and capacitor, through which the tap of the control winding of the drive is connected to the thyristor of the semiconductor element. ............ ha ------- Λ '