SU773809A1 - Device for automatic checking of high-frequency channel of differential phase protection system - Google Patents

Description

In one of the device’s half-sets, the interBfrn time between checks of the high-frequency channel is doubled, the differential-phase protection can be deactivated if the high-frequency channel is damaged only on one side of the line, and the device’s failure can only be detected when it is checked again by service personnel. ; The frequency of automatic testing of a high-frequency channel by a known device does not depend on the state of the protected line, although damage to the high-frequency channel during short circuits on the line is more likely than in normal mode. These drawbacks can lead to a delay in detecting a malfunction of the high-frequency channel and withdrawal from the differential-phase protection and, consequently, to an excessive activation of this protection during external short circuits.

The purpose of the invention is to increase the reliability and speed of the device by performing an additional start on the half-set, which did not receive a ringing signal from the other half-set at a given time, and also by performing an additional two-way test of the high-frequency channel after a short circuit on the protected line.

This goal is achieved by the fact that in the known device for automatic testing of a high-frequency channel differential-phase protection, containing two half sets, each of which consists of a time counter, a starting block, a response block, an OR element, a measuring and an execution block, the first output of the starting block and the output of the response unit through the OR element is connected to the start circuit of the high-frequency channel transmitter, the second output of the starting unit is connected to the second input of the execution unit, the input of the unit the face and the first input of the executive unit are connected to the output of the measuring unit; the input of which is connected to the output of the receiver of the high-frequency channel, and the output of the executive unit is connected to the differential-phase protection circuits, time counters are used, equipped with the installation input to the zero position and additionally introduced into each half-set trigger, two delay elements, three elements And two the OR element and the signal element, the R-input of the trigger through the first delay element is connected to the second output of the starting block, the S-input of the trigger is connected to the output of the Response unit, both of the trigger input are connected by the first element OR the set-up to zero position, a time counter, to the output of which the first input of the first element is connected AND, and through the second delay element, the first input of the third element AND, the second input of the first element AND is connected to the single output of the trigger, to the zero output of the trigger, the outputs of the first and second elements And through the second element OR connected to the input of the starting block, the output of the second element And connected to the first input of the third element And, whose second input is connected to volts The output of the starting block, the third inverted input is connected to the output of the actuating unit, and the output is connected to the input of the signal element.

In addition, the second trigger, the third and fourth delay elements, the fourth and fifth And elements are additionally introduced into the known device, with the S-input of the second trigger connected to the output of the differential-phase oscillator, and its R-input connected to the R-input of the first trigger , the input of the third delay element is connected to the output of the fourth And element, the input of which is connected to the single outputs of the first and second triggers, the input of the fourth delay element is connected to the output of the fifth And element, the first input of which is connected to the zero output the first trigger, and the second input is connected to the single output of the second trigger, the outputs of the third and fourth delay elements are connected to the third and fourth inputs of the second OR element.

The invention is illustrated by the block diagram showing power lines 1 with switches 2.3, current transformers 4.5, barriers 6.7, capacitors 8.9 for connecting transmitters 10.11 and receivers 12, 13 of high frequency channel differential phase protection consisting of relay semi-sets 14, 15, semi-sets 16, 17 of the device for automatic testing of the high-frequency channel, each of which contains a time counter 18, a starting unit 19, a response unit 20, a measuring unit 21, an execution unit 22, cops 23–25 OR, elements 26–30 AND, elements 31–34 of the Alert, triggers 35.36, and signal element 37.

The device works as follows.

In the initial state, the time counters 18 and the triggers 35 of both semi-sets 16 and 17 of the device are in the zero position, the trigger 36 of one of the semi-sets, for example, 16 is in the single position, and the t {5igger 36 of semi-set 17 is in the zero.

After a predetermined time has elapsed, the outputs of time counters 18 pog: are signals. In half 16, the signal of time counter 18 through element 28 I and element 24 OR is fed to the input of starting block 19, since at the other input of element 28 of this half set there is a signal from trigger 36, Start block 19 through element 25 OR starts transmitter 10. High-frequency the signal passes through capacitor 8, line 1, capacitor 9 and is received by receiver 13.

If the channel is healthy, the measuring unit 21 of the half-set 17 sends a signal to the response unit 20. Transmitter 11 is launched through OR element 25. If the signal is received by receiver 12 and evaluated by the measuring unit 21 of the half-set 16. At the moment of receiving the high-frequency signal from the transmitter 11, a signal appears at the second output of the starting block 19 of the half-set 16 acting on the executive unit 22. But since the high-frequency channel is healthy, the signal at the output of the measuring unit 21 blocks the appearance of the signal at the output of the execution unit 22.

The signal at the second output of the starting block 19 through the delay element 34 also acts on the trigger 36, setting it to the zero position

In the half 17, its trigger 36 is affected by the signal from the output of the response block 20 and establishes its single position. At the same time, in both semi-sets, through element 23 OR, time counters 18 are set to the zero position. At the next occurrence of signals at the outputs of the counters 18 times, the half-set 17 starts up, and the half-set 16 provides the response of the transmitter 10 to this start-up.

If the high-frequency channel is faulty, then at the next start-up, for example, half-set 17, the high-frequency signal of transmitter 11 will either not be received at all by receiver 12, or it will be received attenuated. At the output of the measuring unit 21 of the half-set 16, the signal does not appear and the response unit 20 will not operate.

Semi-set 17, without receiving a signal from the transmitter 10, through its executive unit 22 removes the relay semi-set 15 of differential-phase protection from operation.

In the half-set 16, which did not receive a sufficiently large ringing signal at a given time, the trigger 36 remains in the zero position. The signal from the output of the time counter 18 through the delay element 33 is fed to the input of the AND element 29, at another input of which there is already a signal from the left output the trigger 36, and then through the element 24 OR - to the input of the starting block 19. There is an additional start-up of the transmitter 10 and the decommissioning of the relay semi-set 14 of the differential-phase protection.

Thus, in the case of a faulty high-frequency channel, the differential-phase protection is removed from operation on both sides of the protected line with a minimum delay.

An additional start-up of one of the half sets, for example 16, also takes place in the event of failure of the elements of the other half set 17 - counting 5 time 18 or starting block 19.

If the signal does not appear during the additional start-up of the semi-kit 16, then the set of signals at the inputs of elements 30 And will correspond to

0 to a single signal at its output. The signal element 37 of the half-set 16 will operate and notify the operating personnel about the failure of the half-set 17.

five

Thus, the failure of any of the semi-kits is detected faster than when the device is checked by service personnel, which increases the reliability of the device operation.

0

In the event of a short circuit on the protected line, the relay semi-sets of 14.15 differential-phase protection are triggered and give signals to turn off the switches of the 2.3 line 1. At one time, these signals arrive at the S-inputs of the triggers 35 of both semi-sets of the device and set them to a single position.

Depending on the position of the flip-flops 36, with some delay determined by delay elements 31 and 32 an additional two-way test of the high-frequency channel takes place alternately. Trigger 35, element 26 I, delay element 31 (having a shorter time delay than element 32), element 24 OR, starts the first half-set, for example 16, whose trigger 36 is in the single position. At this time, the other half 17 operates in the response mode. After the response, its trigger 36 goes into a single position and provides a similar start of this semi-kit.

If the high-frequency channel is damaged as a result of a short-circuit on the line, then the half-ring 17 will not respond and the relay half-band / set 14 is removed from operation. Following this, the trigger circuit 35, element 27 AND, delay element 32, element 24 OR the semi-set 17 will start and the relay semi-kit 15 will be taken out of operation.

Claims (2)

Claim 1. Device for automatically checking the high-frequency channel of the differential-phase protection, containing 1® containing two half-sets, each of which. consists of a time counter, a start block, a response block, an OR element, measuring and executive blocks, with the first output of the 15 start block and the output of the response block through an OR element connected to the start circuit of the transmitter of the high-frequency channel, the second output of the start block is connected to the second input - ^ 0 of the executive unit, the input of the unit. The response and the first input of the executive unit are connected to the output of the measuring unit, the input of which is connected to the output of the receiver of the high-frequency _ channel, and the output of the executive unit is connected It is connected to the differential-phase protection circuits, which is noteworthy in that, in order to increase the reliability and speed of the test by performing an additional 30 start-up of the half-set that did not receive the called signal from another at a given moment in time the floor of the kit, · the time meters in it are equipped with an input to the zero position 35, and a trigger, two delay elements, three AND elements, two OR elements and a signal element are additionally introduced into each half-set, and the trigger R-input through dd is the first, delay element .connections is connected to the second output of the launch block, the S-input of the trigger is connected to the output of the response block, both inputs of the trigger are connected through the first element OR to the installation input at the zero position of the time counter ^ ^ 5 ka, the output of which is connected to the first input of the first AND element and through the second delay element, the first input of the second element And, the second input of the first element And is connected to a single output of the trigger, the second input of the second element And is connected to the zero output of the trigger, the outputs of the first and second elements And through the second OR element are connected to at the start of the starting block, the output of the second AND element is connected to the first input of the third And element, in which the second input is connected to the second output of the starting block, the third inverse input is connected to the output of the executive unit, and the output is connected to the input of the signal element. 2. Device pop. 1, characterized in that, in order to improve performance: by performing an additional two-way check of the high-frequency channel after a short circuit of an unprotected line, a second trigger, third and fourth delay elements, fourth and fifth elements, and moreover, the S-input of the second trigger is connected to the output of the differential-phase protection, and its R-input is connected to the R-input of the first trigger ', the input of the third delay element is connected to the output of the fourth element And, the inputs of which are are connected to the single outputs of the first and second triggers, the input of the fourth delay element is connected to the output of the fifth element And, the first input of which is connected to the zero output of the first trigger, and the second input is connected to the single output of the second trigger, the outputs of the third and fourth delay elements are connected to the third and the fourth inputs of the OR element.