Transmission line single-phase adaptive reclosing implementing method based on fault point voltage

Abstract

The invention belongs to electric power system transmission line relay protection field and relates to a method for judging failure property of single-phase self-adapting reclosing based on fault point voltage: real-timely acquiring the voltage and current value of every phase on one side of the transmission line; measuring failure distance; real-timely computing the current actual fault point voltage; finding out the sound phase current and fault phase voltage at the two ends of the line, then finding out the approximate open circuit voltage of the fault point and the set-pressure using the result of sound phase current and fault phase voltage and the result of failure distance measurement; comparing the fault point voltage with the set-pressure, an instantaneous failure is judged if the fault point voltage value is persistently larger than the set-pressure within the set time period after single phase tripping, and the protection sends out a reclosing order after certain time delay; an permanent failure is judged if the fault point voltage value is always smaller than the set-pressure within the set time period, and the protection will not reclose after tripping off the three phase line. The invention can ensure the persistency and stability of system power supply and avoid the damage by single phase reclosing and permanent failure to electric equipment.

Description

technical field [0001] The invention belongs to the field of relay protection of power system transmission lines, and in particular relates to a method for realizing automatic reclosing of power system transmission lines. Background technique [0002] Most of the faults on high-voltage overhead lines are instantaneous, and the normal operation of the system can be restored by reconnecting the line after the arc is extinguished at the fault point. Therefore, in order to ensure the continuous and stable power supply of the power system, automatic reclosing technology widely used. However, the automatic reclosing devices currently in practical use blindly reclose after the circuit breaker trips, and cannot judge transient faults and permanent faults. Once a permanent fault occurs, not only cannot the normal power supply of the system be restored, but the secondary impact on the electrical equipment caused by the reclosed fault will exceed the damage caused by a short circuit u...

AI Technical Summary

Problems solved by technology

For heavy-duty long-distance transmission lines, the line mutual inductance voltage is very large, and the probability of misjudgment will be very high; for lines with shunt reactor compensation, the compensation effect of shunt reactors makes the recovery voltage of the fault phase very small, so the voltage There is also the possibility of misjudgment in the criterion; when the fault point is grounded through the transition resistance, it may also cause misjudgment

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