SU1644286A1 - Method for finding faulty transmission line section using devices of limited switching capacity - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to relay protection of electrical installations. The purpose of the invention is to expand the field of application of sectional devices with limited switching capacity. The goal is achieved by the fact that the sectioning apparatuses through which the short circuit current flows disconnects the main circuit breaker in the second cycle of the automatic recloser, if during the sequence of switching on the sectioning apparatus, after the next sectional apparatus is turned on, the main switch is disconnected, during the pause of the first AR cycle, the specified sectioning device is turned off and the head switch is turned off from AR; and when the damaged section of the line is switched on from the backup power supply nearest to the month, in short circuit the sectioning apparatus, its shutdown is performed after switching off the ATS switch. 1 il. with s

Description

The invention relates to the power industry, namely to the means of emergency control of power lines,

The purpose of the invention is to expand the scope of application of partitioning machines with limited switching capacity.

The drawing shows a two-way power line diagram of the transmission line and a block diagram of the control unit of the sectioning apparatus (CA), explaining how to isolate the damaged area.

The device for implementing the method contains traversing switches 1, 2 interconnected power lines. These switches have relay protection units 3 and automatic restarting 4. The lines are connected through a normally disconnected circuit breaker ABP 5 and repeatedly partitioned by sectioning devices (CA) 6 equipped with control units (CU) 7, which have voltage sensors 8, 9, current sensor 10, element OR 11, ten elements AND 12-21, four elements NOT 22-25, four delay elements 26-29, six elements n m minute (triggers) 30-35.

The device works as follows.

In the normal mode, the output of the And 14 element is logical 1, which sets the triggers 30-33 to the state of logical 0 at the output, the signal of the logical 1 from the output of the element And 12 sets the trigger 34 to the state of logical 1 at the output, and the trigger 35 to niya

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logical 0 at the output. When a stable short circuit (short circuit) occurs, the main circuit breaker is turned off. Follows the first pause of the ARC. At the same time, logical 1 arrives at the input of the R-flip-flop 30 from the output of the And 13 element, which translates the flip-flop 30 into the logical 1 state at the output. The automatic reclosing unit 4 activates a switch on a non-removable short circuit. In this case, the signal of logical 1 arrives at both inputs of the AND 15 element. Logic 1 from the output of the AND 15 element transfers the trigger 31 to the logical 1 state at the output. After the main switch is disconnected by the maximum current protection 3, the second pause of the automatic reclosing to the both inputs of the element 16 enters logical 1, logical 1 from the output of this element enters the input of the r-flip-flop 32. the second input element And 17 -logical 1, which leads to the appearance of a logical 1 at the output of the element And 17 and disconnection of the second switch of the ARC of the main switch. Logical 1 from the output of trigger 30 with a delay defined by element 29 is fed to the input of R-flip-flop 33, which puts it in a state of logical 1 at the output. A logical 0 from the output of the element NOT 22 enters the second input of the element AND 17 and prohibits the shutdown of the second reclosure in the second pause (allows disabling in the first pause).

The power line switch is turned on. At the same time, at the output of element 19, a logical 1 signal appears, which, with a delay T1 created by the delay element 28, arrives at the second input of element 21, the first input of which contains logical 1 from the output of trigger 34, which leads to the activation of CA. If the activation occurred on the intact region, then the circuit returns to its original state, i.e. disabling the SA becomes possible only during the second pause of the automatic reclosing.

If the CA turned on the damaged section, then the logical 3 from the output of the AND 20 element goes to the input of the 3-flip-flop 34, and the logical 0 from the output of the 12-W element of the output of the 12, which leads to the switching of the flip-flop 34 to the logical 0 state which, entering the input of the element 21, blocks the activation of the CA. At the same time, the logical signal 0 from the output of the trigger 34 is inverted by the NOT 25 element, and a logical 1 from the output of this element appears at the first input of the AND 18 element.

leads to the appearance at the input of the delay element 27 the logical 1. The SA is turned off during the first pause of the automatic reclosing and is blocked from being turned on.

Next include the switch AVR 5.

At the same time, in the control unit 7 SAb, located between the short-circuit point and the ATS switch 5, the same processes are repeated as when the main switch is turned on by the ARF 4 after

first pause auto-reclose. As a result, during the second pause of the automatic reclosing switch ABP 5, the circuit breaker is disconnected and locked from switching on the one closest to the location of short circuit CA b from the backup power supply side.

Thus, the method of isolating a damaged section of a transmission line using switching devices with limited breaking capacity allows expanding the scope of application of sectioning devices with limited switching capacity, thereby reducing the cost of partitioning points and creates prerequisites for wide automation, which allows

improve the reliability of electricity supply to agricultural consumers.

Claims (1)

Claims of the invention A method for isolating a damaged portion of a transmission line by means of switching devices with limited breaking capacity, which means that when a short circuit occurs on a line, it is turned off a head switch equipped with a maximum current protection and two-time automatic reclosing switch on it from automatic reclosing, with a stable short-circuit re-disconnecting the main switch, disconnecting the sectioning devices through which the short-circuit current passed, turning on the main switch from automatic reclosing, sequentially turning on the sectioning devices after the occurrence they are strained turn off that sectioning device, when turned on, a short-circuit current appears, turn on the ATS switch, turn it off from protection, turn off those sectioning devices through which the short-circuit current passes, turn on the ATS switch from AR, sequentially turn on the sectioning devices after the occurrence they are energized, the sectioning device is turned off, when turned on, a short-circuit current appeared, turn off the AVR switch and turn it on from the automatic reclosure, characterized in that, in order to expand Neither the application area of sectioning apparatuses with limited switching capacity, sectioning apparatuses through which the short-circuit current flowed, disconnect in the pause of the second cycle of the automatic reclosing switch of the main switch, if the sectioning apparatuses are switched on sequentially, after the next sectioning apparatus is turned on, the short-circuit current appears head switch paused The first cycle of the automatic reclosing system turns off the indicated sectioning device and turns on the automatic switch from the automatic reclosing, and when the damaged line section is turned on from the backup power supply closest to the sectional circuit short circuit, it is disconnected after turning off the automatic breaker switch. Off S 1st pause