SU132705A1 - The method of pulse control of the state of the transmission line and device for implementing the method - Google Patents

Description

The known methods of pulse control of the state of the transmission line are carried out by means of devices that block the re-activation in the presence of damage in the line and usually contain the power supply unit to the power line wires, the control system start-up unit, the pulse generator, the power supply unit and the receiver with the amplifier of the specified pulses, to the input of which a blocking relay circuit is connected.

The described method is characterized by the fact that as a blocking signal voltage pulses are used, opposite in sign to the sounding voltage pulses sent to the line to check its state; In the receiver of the device for carrying out the described method, a detector is applied, which transmits only pulses in the blocking circuit, which are opposite in sign to the probe pulses.

This makes it possible to simplify the circuit of the pulse control device by excluding from it the blocks for reproducing the impulse response of the line and comparing the probe and reflected pulses.

The drawing shows a schematic diagram of the described device.

Since the application of the proposed method of pulse selection, their frequency and shape practically do not play a role and only requires that the polarity of the pulses do not change, a device for implementing this method can be assembled on semiconductor devices.

The unit / attachment to the monitored line is a coupling / CC coupling capacitor with an attachment filter or other device capable of separating the automation circuit from the high voltage line and freely passing pulses.

 132705- 2 The start-up unit 2 contains, in the control and automatic reclosing (AR) devices, the contacts of the control key and the start-up protection of the relay protection, which consists of the relay of the RH protection and the block contacts for switching on the VFB; in devices combining protection and start-up functions, a voltage wave generated at the point of damage at the time of its occurrence should be used to trigger.

The pulse generator 3 consists of a self-excited blocking generator on the PP triode and a power amplifier PP. Pulses are fed to the power line (LEP) through a step-up pulse transformer TI, a semiconductor PP diode and an artificial IL line. A shunt diode PP is provided in the circuit to reduce the surge voltage on the collector but at the end of the pulse.

Receiver 4 consists of an amplifier on a PP triode and a limiter made on a PPT Zener diode providing a pulse of constant amplitude to the counter. The receiver is connected to power lines through a pulse transformer T and the detector is a semiconductor PSD diode. This ensures that the device is electrically separated from the system of connection and that emitted pulses with the desired polarity enter the receiver oiv.

The executive and blocking unit 5 consists of a pulse counter on a semiconductor diode I // 8, a capacitor C, an RIZ actuating relay with a PP triode and a blocking relay RB.

The power supply unit 6 consists of a semiconductor rectifier assembled according to a bridge circuit and a power transformer. Power can also be supplied from a battery by connecting the -LJ and + fy terminals to the appropriate voltage divider.

The device is activated by a blocking contact of the linear disconnector BK, P, which ensures the automation of the output of the device from operation. In addition, it can be removed from operation with the aid of an overlay I. After switching on the linear disconnector, an alternating current is applied to the circuit. After a period of time determined by the setpoint, which is regulated by the resistance RZ, the capacitor Cz is charged and the rest of the circuit is de-energized, which is the normal starting position.

In the event of damage to the LZP, the relay of protection of RZ activates simultaneously into the start-up unit 2. The relay of protection of RZ, together with the sending of a shutdown pulse, supplies the anode power to the circuit, as a result of which the generator of 3 pulses starts to send negative polarity pulses to the power lines. In the receiver 4, these pulses do not fall, since the diode PP blocks their path. If there is a short circuit on the power transmission line, the pulses are reflected with reverse polarity and fall into the primary winding of the transformer T, since the secondary winding of the transformer TI represents a much greater resistance for them. Further, the reflected pulses are amplified, limited and fed to the capacitor Ci. The potential of capacitor Cj rises and unlocks the YDT triode, and the RIZ relay triggers. The control device is put into operation before the switch has time to open, which is a sufficient condition for the RIZ relay to operate, regardless of whether the damage has recovered by this time or not. The reason for this is wave processes at the time of damage and interference on power transmission lines. When activated, the relay RIZ opens its normally closed contact, as a result of which the circuit breaker opens. At the same time, the normally open contact of the same relay is closed, through which power is supplied to the winding of the RB relay. The latter closes its normally open contacts. One contact of the relay RB is self-holding until the Ca capacitor is completely discharged, and the second contact is preparing the circuit for switching the switch. The relay RB is introduced into the circuit in order to avoid multiple re-activations in the event of damage to the RIZ relay or the insensitivity of the adopted connection pattern to this fault type. In these cases, the normally closed contact of the RIZ relay in the on circuit of the switch is closed, but the on circuit is opened in the contacts of the relay RB. After the switch is disconnected, the relay relay contacts return to their original position, but the device circuit continues to receive power through the auxiliary contacts of the CBV switch and, therefore, the generator continues to send pulses.

There may be two cases. If the damage was transient, then after switching off the switch, the arc goes out, the probe pulses are reflected with the same polarity, and the flow of pulses to the receiver stops. The RIZ relay returns to its normal position and with its normally closed contact creates a circuit to turn on the switch. The switch is turned on if its position does not correspond to the position of the control circuit. The whole circuit comes to its original position, but readiness for subsequent action occurs only after the time required for the charge of capacitor C2 to expire, starting only after the winding of the relay RB is disconnected from capacitor Cr, and the charge circuit is restored.

If the damage on the power transmission lines has not been eliminated or there are short circuits left on it, the reflected pulses with the polarity opposite to the probe pulse are fed to the receiver input, and the VIS relay is interrupted by the switching circuit. After the set time and discharge time of € 2, the RB relay also interrupts this circuit. The switch is not turned on again.

When power lines are turned on after repairs and generally when they are turned on under voltage, as a rule, the linear disconnector is first turned on. In this case, the control circuit begins to operate, since when the switch is turned off, the power supply circuit is closed through the auxiliary contacts BKV.

If the power transmission line is working and all the grounding is removed, then the RIZ relay remains at normal poloslenii and when the control key is turned to the on position, the RB relay is energized via contact K of the manual control key, the on circuit of the switch is closed and the switch is turned on. In the presence of damage, short-circuiting or disconnection of the short-circuit of the RIZ relay, and then the RB relay, interrupt the switching circuit, and the manual switching of the switch does not occur.

For each specific case, when using the described device, depending on the parameters of the power transmission lines and its switch, the following settings of the circuit elements should be specified.

The time setting for the preparation of the switching circuit of the RB relay, regulated by a variable resistance. This time is chosen so that the switch has been able to disconnect for the second time both from the main and from the backup protections and that the transient phenomena in the power lines disappear. The ego is necessary in order for the RIZ relay to return to its normal position even if there is damage that is not perceived by the attachment device. In this case, the switch-on circuit of the RB relay does not close at the contacts of the RIZ relay, and automatic reclosing in all cases will be one-time, i.e. the possibility of reclosing to the damaged power lines is excluded.

- 3 - .№ 132705

l 132705- 4 The time setting of the RB relay for disconnection, which is determined by the number of copper washers slowing the relay down and the capacitance Cz. This setting is chosen such that its lower limit provides a sufficiently long starting pulse to reliably turn on the switch and the upper limit prevents the second AR cycle.

Reset time relay setting. This switch-on setting is determined by the capacitance capacitor Ci of the pulse counter circuit. This capacitance is chosen so that the RIZ relay starts to operate only after receiving at least five reflected pulses, which ensures detuning from random impulse noise. At the same time, this setting should not exceed the switch off time in order to ensure the operation of the RIZ relay.

The sensitivity setting of the RIZ relay. This setting is defined as a percentage as the ratio of the magnitude of the reflected pulse to the sent pulse, which should trigger the relay of the READ to a certain value of the probe pulse. The setting determines the range of the device, which may be limited by the end of the power lines or the tires of the next substation, and is controlled by one of the variable resistances RI and 2. The sensitivity of the device to various damages on the power lines is determined by the unit / attachment. For example, with single-phase connection (see drawing), reverse polarity pulses are obtained only with some short circuits, when the device prohibits automatic reclosing when the short circuit is disconnected, which must be installed on this phase, and with all short circuits to ground or interphase closures x, which involves a phase in which a pulse is applied.

Subject invention

Claims (2)

1. The method of pulse control of the state of the power line before it is turned on under voltage (or psd load), carried out by means of an automatic restarting device or a key controlling the position of the line switch, characterized in that, in order to simplify the control system, as a signal blocking the switching on of the switch, amplified voltage pulses, inverse to the sounding pulses, are sent to the line to check its condition. 2. A device for carrying out the method of claim; comprising a power supply unit to the power line wires, a line monitoring system start unit, a pulse generator, a power supply unit, a receiver with an amplifier of said pulses, to the input of which a blocking relay circuit is connected, in that In order to allow only pulses inverse to the probe pulses to pass to the blocking circuit, a detector is used in the indicated receiver, which transmits only the pulses indicated.