SU1357887A1 - Device for determining direction to short-circuit place in aerial power line - Google Patents

Abstract

A device for determining the direction to a short circuit (short circuit) on an overhead transmission line contains inductive current transducers 1, 2, a max-selector-rectifier 3, a limiter 4, a resistor 5, a transient current separation unit 6, a short-circuit display units 7 8, 9, reference voltage source 10, antenna converter 11, rectifier 12, accumulator 13. The device is reliable in operation when there are double ground locks in the presence of a motor load in the network by controlling the amount of current in each wire SRI has improved power and noise-zashischennost. 2 Il. (О (Л г1 S 6 Р I У V; with SP oo oo f T LJ zigl

Description

one

The invention relates to electrical measurements, technical equipment and can be used in devices for determining the detection of short circuits in branched distribution networks.

The aim of the invention is to increase the reliability of the device in case of double ground loops or the presence of a motor load in the network by controlling the amount of current in each wire of the transmission line and susceptibility to interference

: FIG. 1 shows the scheme of the proposed device; in fig. 2 - mutual arrangement of the I11duction current transducers and air lines of the air line for reinforced concrete and wood supports of the electric transmission line.

The device contains (Fig. 1) induk-lUKJHHbie current transducers 1 and 2 (IPT), max-selector-rectifier 3, suppressor 4, resistor 5 (time setting), block 6 in; ode; 1 Short circuit, indication unit 7, first 8 and second 9 threshold blocks, 1U reference voltage source (ION), anteptic transducer.; 1 11, rectifier 12 and accumulator 13, both IPT 1 and 2 switches are connected to with () from the 5th-1M informational inputs of the max. sector of the rectifier 3, the first output of which) O1 o is connected to the first output of the limiter 4 and after a while one) 3 - with the input of the block 6 for the selection of the transient component of the short-circuit current, the first output of which is connected to the first input of the first threshold organ 8, two inputs of the aptenous transducer 11 are connected to the corresponding inputs of the center 12, the first output of which through the accumulator 13 is connected to the first and second inputs of the second threshold unit 9, with the second input of the first threshold unit 8 p through ION 10 to the reference inputs of both threshold b.yukov 8 and 9, the outputs of which are connected respectively to the inputs of the operation and return of block 7 and 1, and the second output of the max-selector is the rectifier 3, the second output of the limited-. 1 4. The second outputs of the transient current extraction block 6 and the rectifier 12 and the output of the indication block 7 connect the HCinj to the total length.

FIG. 2a shows the mutual arrangement in the space of the wires 14-16 of the power transmission line and IIT 1 and 2 for the reinforced concrete support. FIG. 26 - arrangement of wires 17-19 and IIT 1 p 2 for a wooden hole.

The device works as follows.

IPT 1 is located horizontally, and ICU 2 vertically so that when installed on a concrete support (Fig. 2a) IIT 1 controls the current of the upper wire 14, and 2 - two lower wires 15 and 16, and when installed on a wooden pole (Fig. 26)

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IPT 1 controls the currents of wires 1 / and 19, and IPT 2 controls the currents of wire 18.

If there is a double earth fault at different connections, the short-circuit current can flow through one of the wires of the transmission line, therefore the device for determining the location of the damage should have the same current sensitivity when damaged at any phase of the monitored section of the network. With this in mind, the output signals of IPT 1 and 2 in the device must be the same at different distances from these elements to the Coptro; 1ir.m.1x wires.

By this, the device is equally sensitive to the short-circuit current of any wire. Such an arrangement of IPT 1 and 2 is the only possible one at once, eHHH in the same case. 1 of the indicator, since in this case the indicator should always be placed at the bottom of the housing.

Thus, when any kind of short-circuit is detected at the output of one or both of the IPT 1, 2, the signal sharply increases and, through the max-selector-rectifier 3, which extracts the greatest one, the limiter 4 n time, the setting resistor 5 charges the integrating the capacitor of the block 6 of the irregular component of the short-circuit current, providing a delay in the signal output at its output. Limiter 4 limits the amplitude of the biaxial output of the max-selector-rectifier-tel 3 at the level proportional to the line current of 150 A. The axial load current in the distribution networks does not exceed 100 A. The maximum charging time from electric motors 80 ms. The time setting resistor 5 of the blocking circuit 6 of the transient component of the short-circuit current provides a delay in the appearance of a signal at its output of 100 ms at a signal at the output of the maximum selector-rectifier 3 and a proportional current of 100 A. The limiter 4 also provides protection of IIT 1 and 2, diodes of aux. selector-rectifier 3 n of the first input of the first threshold unit 8 from redundancies, since the short-circuit currents in the lines can reach values of several kilo.mperes. The delay time of 100 ms is chosen taking into account the operation of the current cut-off, during which the line is disconnected after 0.12-0.15 s with short-circuit currents of at least 200 A. The low current of the short-circuit currents is turned off. The maximum current protection after 0.5 -0.6 s, taking into account this time delay, when the current value of the short overcurrent 50 A current is about 0.3 s. The introduction of limiter 4 and the corresponding choice of time parameters — the setting resistor 5 and the integrating capacitor of the separation unit 6; the transient composition; 1, the short-circuit current provides a trigger from the pointer's most destructive actions on the motor load branches. Source 10 onorny

voltage ensures the stability of the threshold without additional adjustment.

If the magnitude of the signal at the output of block 6 of the transition transient component of the short-circuit current exceeds the threshold set by the source 10 of the reference voltage, the first threshold block 8 triggers and discharges the drive 13 through the actuation winding of the display block 7, translating it into a state indicating a short-circuit in the controlled direction.

The device returns to its original state after a successful reclosure or after the damage has been repaired and the line is put into operation as follows. A signal appears on the antenna converter 11, which through the rectifier 12 charges the storage device 13. As the voltage on the storage device 13 increases above the threshold value specified by ION 10, the second threshold unit 9 triggers and discharges the storage unit through the return winding of the display unit 7, returning it to its original position corresponding to the absence of a short circuit in a controlled direction. When returning, the display unit 7 disables the return winding input from the output of the second threshold unit 9 and thereby prevents its repeated trips.

In normal mode, the power of the first 8 and second 9 threshold units and ION 10 is provided from antenna converter 11 via rectifier 12. Power is stored on accumulator 13 to control display unit 7 and operate the device in case of a fault.

Thus, the introduction of the rectifier max-selector and the corresponding IPT placement make it possible to control all types of interfacial faults.

The introduction of a reference voltage source, a limiter, and a master resistor time allows for increased reliability, beyond

Order 5505/46

Production and ioligraphic pre.1. Uzhgorod, st. Design. four

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protection of the device and its efficiency.

Claims (1)

Apparatus of the Invention A device for determining the direction to a short circuit on an overhead transmission line, comprising two induction current transducers, a transient component selection component of a short circuit current, the output of which is connected to the first input of the first threshold unit, the output of which is connected to the input of the display unit, an antenna converter, the outputs of which through a rectifier are connected to the input of the storage device, the output of which is connected to the second input of the first threshold unit and the first the second inputs of the second threshold unit, the output of which is connected to the return input of the display unit, characterized in that, in order to increase the reliability of operation, a max-selector-rectifier, a limiter, a resistor and a reference voltage source are introduced into the device, and the corresponding inputs of the max-selector - the detector is connected to the corresponding outputs of the first and second induction current transducers, the limiter is connected to the corresponding outputs of the Max-selector-rectifier, the first output of which is through inn with the input of the transient current transducer isolation circuit component, the input of the reference voltage source is connected to the accumulator output, and the output is connected to the reference inputs of both threshold units, the second outputs of the maximum selector-rectifier, transient current transducer selection unit, rectifier and the output of the display unit is connected to a common bus, the induction current transducers are located so that the output signal of one of them is proportional to the geometric difference of the currents of the two phases, and the output signal of the second third phase current cheniyu. g / 1 1st I -I to - b: b P (  I .g R-; / I p nineteen I I I 1 №l.Z Circulation 730 Subscription