Permanent high-resistance fault section positioning method based on cascaded H-bridge control

Abstract

The invention relates to a permanent high-resistance fault section positioning method based on cascaded H-bridge control, and belongs to the technical field of power system power distribution networkprotection. According to the method, upstream and downstream of a fault can be effectively identified, the fault section can be quickly positioned, when the system has the single-phase grounding high-resistance fault, the same high-frequency current signal is injected into three phases of a feeder line through the cascaded H-bridge converter, and the three-phase phase current of front and rear measurement points of each section of the line is acquired; a fault phase line grounding point is resistive, high-frequency current cannot pass through the fault phase line grounding point, the front andrear phase current variable quantities of each section of the two non-fault phases and the fault phase are compared, and the section with the maximum variable quantity is a fault section, so that section positioning is effectively realized, the current variable quantity is sensitive to high-resistance fault response and good in quick action, and the method has a sound application prospect.

Description

technical field [0001] The invention belongs to the technical field of power system distribution network protection, and in particular relates to a method for locating a permanent high-resistance fault section based on cascaded H-bridge control. Background technique [0002] The power distribution system is affected by factors such as being close to the ground, feeding into residential areas, and natural disasters. The wires are easy to touch tree branches or break and fall. At this time, high-resistance grounding faults often occur. When a high-resistance grounding fault occurs, it is difficult to detect and cannot be quickly removed. If the fault exists for a long time, it may not only cause a two-phase grounding short circuit fault, expand the fault range and change the nature of the fault, but may even cause a fire. Threats to personal and property safety. As an important part of the power grid, the distribution network is also important to detect and ensure its normal ...

AI Technical Summary

Problems solved by technology

However, the resistance value of high-resistance grounding faults in the distribution network is not clearly defined at present, and the ability of conventional detection and protection devices to respond to grounding resistance does not exceed 300Ω

However, the resistance value of g

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