Fault range finding method of power distribution network based on voltage distribution principle

Abstract

The invention discloses a fault range finding method of a power distribution network based on a voltage distribution principle. According to the method, a PMU is used to obtain line state informationin real time, a fault line is determined by calculating and comparing the head-end line voltages in the same branch point after a fault, and a fault is located in the fault line accurately via the voltage distribution principle. Branch influencing factors in the traditional power distribution network fault locating method can be eliminated, and the fault can be located rapidly and accurately; fault range finding is realized by measurement in the two ends, influence of a transitional resistor is eliminated principally, and compared with a single-end measurement method, the range finding precision is higher, measurement is not influenced by the fault type, it is not required to mount the PMU in the two ends, cost of equipment is reduced, and the application prospect is better; and the methodcan be used to realize fault range finding rapidly and effectively, and the operational reliability, safety and flexibility of the system can be improved greatly.

Description

technical field [0001] The invention belongs to the application field of distribution network fault location, and in particular relates to a distribution network fault location method based on the principle of voltage distribution. Background technique [0002] With the continuous development of society, power users have higher and higher requirements for power quality and power supply reliability, and urban distribution networks are required to be equipped with fault location systems. In all power outages, power outages caused by distribution network faults account for more than 95%. The rapid and accurate positioning of distribution line faults can not only repair the line as soon as possible to ensure reliable power supply, but also ensure the safety and stability of the entire power system. Economic operation has a very important role. However, the existing fault location process has the problems of slow location speed and inaccurate location results, which can easily c...

AI Technical Summary

Problems solved by technology

[0004] There are many branches in the distribution network, which is no longer a simple structure of "two points and one line" in the high-voltage system. The fault location is complicated, and the distribution line is short, so the accuracy of fault location is high. The traditional fault location algorithm can no longer Applicable to distribution network

The impedance method uses the voltage and current measured at the time of the fault to calculate the impedance of the fault loop, and the length of the line is proportional to the impedance, so as to obtain the fault distance. The principle of this method is simple and easy to implement, but it is greatly affected by the transition resistance, especially For distribution lines with multiple branches, false fault points cannot be ruled out

The traveling wave method is widely used in high-voltage transmission fault location. The fault distance of the line is determined by measuring the propagation time of the voltage and current traveling waves between the fault point and the busbar. The distance measurement accuracy is high. The line is short, and the travel wave is reflected back and forth, which makes it difficult to detect the head of the fault travel wave. How to effectively extract fault information is also a difficulty in fault location

[0005] Based on the above analysis, in view of the large number of distribution network feeders, short line length, and wide power supply range, the existing fault location has the problems of slow location speed and inaccurate location results, which affects the reliability of the power system.

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