SU89298A1 - Power Line Protection - Google Patents

Description

This invention relates to ultrafast protection of lines and transmissions against short circuits.

In the technique of relay protection, protection with the shaking of an impulse impulse to the opposite end of the protected line is known, and the signal of this pulse is caused by the operation of electromechanical contacts.

The purpose of the invention is the super-fast simultaneous disconnection of off-blades at both ends of the newly-established line during a short circuit in the zone.

For this purpose, a non-inertial sending of the pulse from the detector circuits to the opposite end of the lignNII from the detector is used, the polarity at the output of which depends on whether the short circuit is located within or outside the protection zone.

The drawing shows a schematic and electrical circuit for on-line protection.

In the event of a short circuit on L1shi at the start of at least one of the high-frequency transmitter relays in the anod.dnoy circuit of both receivers at the ends of the line quickly and simultaneously turns off both switches.

As a detector circuit, a device is applied that compares two electrical values, as a result, a voltage of such polarity is obtained at the output terminals of the device that, when damaged, a transmitter is instantly triggered in the protection zone, which locks when external short.

The detector circuit can be characterized by a remote directional ohmmeter, a cut-off current probe, or another.

As is known, the characteristic of any type of remote ohmmeter can be obtained by comparing the magnitude of the two voltages. For example, to get a remote wired MHO relay, it’s enough to compare

the magnitude of the measured voltages UL (iL-1) (((I 9 j where 2 is the resistance of the protected zone, X is the current.

In turn, the current cutoff characteristic can be obtained by comparing the magnitude of the rectified voltage KI with a constant load voltage.

The device may have a three-phase or single-system filter design, depending on the choice of the detector circuit.

As a result, the naming of the detector circuits in combination with the transceivers of the relay I in the anode circuit of receiver 2 is the only electromechanical relay, and if necessary, further acceleration of the action of the switchboard can be replaced by a thyratron.

In case it is desirable that the protection act to turn off the switch regardless of the high-frequency device, the output of the detector circuit must be a separate relay 3 or an additional relay coil in the anode circuit of the receiver.

In the case of the need for an ultrafast simultaneous phase-by-phase disconnection of the breakers, the tripping pulses can be transmitted by sending a high-frequency signal modulated for each of the three phases with a different tone frequency.

The drawing is a schematic diagram of the connection of the detector circuit with the transceiver. If it is necessary to stabilize the voltage gain at the output of the detector circuit, the corresponding device is included in the transceiver 2-4.

Solid detectors or anectron-ion devices can be used as detectors 5.

Selective action of the relay of the anode circuit of the receiver with external high-frequency noise may be provided by an increase in the current of moving the relay or additional control of the tripping circuit with an ohmmeter of the second or third stage.

- 2 MHz.

 i

SUBJECT OF INVENTION

Protection of power transmission lines with the use of detector circuits comparing the electrical values of the current detection rate in the protected zone, characterized in that a fast-acting and fast disconnecting switch at both ends of the protected line during a short circuit in the zone is applied to the opposite end of the circuit breaker the disconnecting pulse lines from the detector are oem, the polarity at the output of which depends on whether the damage occurred. zone or ane zone protection.

D / vv-i

Circuit off