SU474879A1 - Device for non-selective disconnecting high voltage circuit breakers - Google Patents

Description

Devices are known for nonselective disconnection of high voltage breakers of intact equipment for limiting short-circuit current .1g on the breaker of damaged equipment, containing main thyristors in disconnecting circuits and fast response phases: fast measuring organs, fast-acting automatic disconnecting setting from repeated inclusion.

However, these devices do not limit the short-circuit currents during automatic re-opening of the switch at the moment it is turned on, although in some cases the permissible switching current limits the switching capacity of the switch and the short-circuit current at switching on may have a greater value.

In the proposed device for limiting short-circuit current through a switch of damaged equipment when it is automatically switched on to an unresponsive short-circuit, the control circuit of the main thyristor is connected to the secondary winding of a pulse transformer, one il. And several primary windings of which are connected to the measuring bodies, and the other through blocking thyristor, controlled by additional pulse

transformator tokhom basic te ,,; .In parallel, the connected contacts of the 1st output; the common relays of the automatic restart are interrupted; II minus the source: pntal: 1.

In addition, to increase reliability, a second differentiating circuit connected in series with an actor, the second differential circuit from one side is not connected to the operational plus of the main thyristors, and is connected to the thyristor blocking thyristor with a series-connected diode and a differentiating circuit. the other is through the dynnistor and resistor to the operational minus.

To simplify the second primary winding of the pulse transformer of the main thyristor, one output is connected to the blocking thyristor, and the other through a resistor and diode to the common point of the corresponding circuits of all phases.

The drawing shows a block diagram of the proposed device.

Device contains exit / lockout

from repeated inclusion; item 2; organ 3 of the action of relay protections on the protected equipment; 4 main thyristors in the high voltage circuit breaker tripping circuit; pulse tra) 1formator 5 dl

controlling the main thyristor 4; additional pulse transformer 6 for controlling the thyristor 7; fast measuring devices 8 l 9; switch control circuit 10 in part of its disconnection; high phase voltage switch A; high-speed1. phased automatic reclosing 12; circuit breaker control circuit 13 in connection with its activation; logical element NLP 14; interlocking action 15 (switch; dinstor 16; separator diode 17; contacts 18, 19 and 20 automatic reclosing relays; devices 21 and 22 for phase B and C switches; phase B and C circuit breakers 23 and 26 in part switching off; circuits 24 and 27 of the control of the switches of phases 5 and C in the part of the turned on1;

The principle of operation of the device is based on the opening of the NII of the blocking thyristor 7 at the time of unlocking the main thyristor 4 through a pulse transformer 5 operating the measurement unit (s). To accurately determine the need for reducing the short-circuit current, measuring units can be installed on all connections by adding the required number of primary windings to the pulse transformer. At the moment of off: Iran, and the blocking thyristor 7, the diplistor Jl6 is closed. Prior to charging the capacitor through diode 17 to the level of the voltage, the sample breaker 16 prepares the circuit for the current in the secondary circuit of the transformer 5. At the moment of applying the pulse to switching on the breaker of the damaged equipment, the circuit through the secondary winding of the pulse transformer 5 is opened. Since the switch off time is less than the on time, the adjacent switch is turned off before the switch of the damaged equipment is turned on.

Subject invention

Claims (3)

1. The device for nonselective phase switch of high switches on: 1p zheyi, soa.rzhan; its main T11rist0;) at prices x phase off and phase high-speed measuring bodies, fast-acting phase-by-phase automatic repeated switching on with blocking from repeated switching on, different topics. , in order to limit the short-circuit current through the switch of the damaged equipment when it is switched on automatically to an intermittent short circuit, which controls the main thyristor circuit to the secondary winding of the pulse transformer, one or several primary lybtx windings of which are connected to the measuring organs, and the other through a thyristor blocking current controlled through an additional pulse transformer by the main thyristor current to the parallel-connected contacts of the output relays of the automatic rectifier: key switch and minus the source. 2. The device according to claim 1, characterized in that, in order to increase reliability, a thyristor with a series-connected diode and a differentiating circuit from the capacitor and an adjustable resistor are connected parallel to the second dyno-center circuit connected in series with the dynistor, and on the one hand, the second differentiating path is connected to the operative plus of the main thyristors, and the other, through a dynistor and a resistor, to the operational prompt minus. 3. The device according to claim 1, characterized in that, in order to simplify, the second primary winding of the pulse transformer of the main thyristor is connected to the blocking thyristor with one output and the other, through the resistor and diode to the common point of each phase.