Small current grounding comprehensive wire selection method based on electric quantity and non-electric quantity

Abstract

The invention discloses a small current grounding comprehensive wire selection method based on electric quantity and non-electric quantity. The method includes the following steps: if a bus voltage abnormal alert is started, acquiring a zero-sequence current of a voltage abnormal bus associated line, determining whether it is established that a certain line has the largest zero-sequence current and the largest zero-sequence current is the sum of zero-sequence currents of the other lines, and if it is established, the line has a grounding breakdown; and if it is not established, acquiring the non-electric quantity information of the voltage abnormal bus associated line, using the method of weighting to compute breakdown probability of each line, successively cutting and removing corresponding lines according to the sequence of the breakdown probability, if the bus voltage returns to normal, then determining that the line has a grounding breakdown. The method can schedule a main station end and accurately identify lines with grounding breakdowns, enables closed-loop processing through remote controlling in a fast and efficient manner, increases the accuracy of small current grounding and switching off, shortens time for processing breakdowns, reduces the work load of scheduling workers, and effectively ensures reliability of grid power supply.

Description

technical field [0001] The invention relates to a comprehensive line selection method for small current grounding based on electrical quantities and non-electrical quantities, and belongs to the field of power system scheduling automation. Background technique [0002] The power system can be divided into large current grounding system (including direct grounding, reactance grounding and low resistance grounding) and small current grounding system (including high resistance grounding, arc suppression coil grounding and non-grounding) according to the grounding method. Most of my country's 3-66kV power system adopts the operation mode of ungrounded neutral point or grounded through arc suppression coil, which is a small current grounding system. In the small current grounding system, single-phase grounding is a common temporary fault, and it often occurs in regional power grids, especially 10kV distribution lines. [0003] After a single-phase grounding occurs, the voltage o...

AI Technical Summary

Problems solved by technology

One is to install a small-current grounding line selection device in the substation, but the single-phase grounding fault conditions of the power grid are complex and diverse, and the small-current grounding line selection system often only uses a certain aspect of the fault characteristics, and the accuracy is not high. The lack of willingness has led to the unreliable signal of the small current grounding line selection system at most station terminals, and even out of operation

Another way is to use manual line selection, that is, through the dispatching of the alarm information received by the master station system, manually screen and judge the grounding line, and then notify the operator to conduct on-site investigation and processing. This method has a low degree of automation and mainly relies on manual experience. Auxiliary decision-making means for line selection, and the efficiency of accident handling is not high

[0005] With the continuous improvement of dispatching automation level, the master station's information collection capabilities and comprehensive analysis capabilities are becoming more and more comprehensive. At the same time, integrated regulation and control technology has been gradually promoted and fully applied to regional power grid dispatching control systems. The traditional remote control operation method can no longer To meet the needs of technological development, it will be normal for control personnel to use remote remote control to open faulty lines on the main station side

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