Non-failure valve tripping criteria recognizing breaking point based on local measurement

Abstract

The invention discloses a fault-free tripping operation criterion based on local measurement to identify the distance between an opening point and a breakpoint. The fault-free tripping operation criterion comprises the following steps: firstly, detecting the starting of break variable, recording the starting time, conserving current, power and switch position signal information before starting, detecting the power of 200ms before starting, judging whether current has the rapid drop process or not in the process of disturbing, if switch position signals are detected to disappear in the process of starting, and current is detected to near zero, and judging local fault-free tripping operation after delaying, if current is not near zero, and detecting current, active power, reactive power and positive sequence impedance by a device after starting, if current is stabilized on a lower value, line power flow is totally capacitive reactive power, measured impedance is equal to open-circuit impedance which is set in advance, and judging remote fault-free tripping operation criterion after delaying. The fault-free tripping operation criterion can effectively distinguish the processes of local jumping, remote jumping and, which has excellent adaptability in segmented circuits.

Description

technical field [0001] The invention belongs to the technical field of power system automation, and more precisely, the invention relates to a fault-free tripping criterion based on local measurement to identify the distance of a breaking point. Background technique [0002] The N-1 fault or N-2 fault of power transmission equipment is the most common disturbance accident in the power system, and it is the basic basis for the safety and stability control of the power system, overload control, and fast switching of power consumption of power plant units. The safety and stability analysis of the actual system shows that in the case of strong power flow in the electromagnetic ring network, the non-fault jumper of the single-circuit high-level voltage line electromagnetic ring network is more serious than the single permanent fault. Therefore, it is very necessary to study the no-fault tripping criterion. [0003] The reasons for transmission line tripping include relay protect...

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Problems solved by technology

[0005] Document 1 "Analysis and Application of Tripping Criterion for AC Equipment Used in Stability Control" (Power System Automation, April 2007, Volume 31, Issue 8, Page 46) proposes a criterion for judging non-fault tripping based on changes in electrical quantities , which is also a popular criterion now. The main problem of this criterion is: when the system is disturbed to redistribute the load, and the remaining power after the power flow transfer on the line is very small, the device will misjudge it as no matter how long the delay is. No fault trip

[0006] Document 2 "New Criterion for No-Fault Trip Based on Local Electrical Quantity" (Power System Automation, February 2008, Volume 32, No. 3, Page 46) proposes a criterion for judging no-fault tripping based on changes in local electrical quantities , which theoretically distinguishes the process of tripping on the opposite side and the process of power flow transfer. The main problems of this criterion are: the judgment of tripping on this side is too simple, and the reliability needs to be strengthened; there is no good solution for the segmented lines with switching stations in the middle. solution

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