Distribution network fault positioning method and system based on non-contact measurement

Abstract

The invention discloses a distribution network fault positioning method and system based on non-contact measurement, and the method comprises the steps: receiving a voltage signal and a current signal sampled by a non-contact sensor disposed on a line, and converting a current amplitude signal into a phasor current according to the voltage signal; calculating action current and braking current according to the phasor current; and carrying out fault positioning according to the action current and the braking current. The wireless communication mode of the non-contact sensor and the power distribution terminal is adopted, an existing circuit structure is not changed, and the method is suitable for digital upgrading and reconstruction of existing equipment; based on longitudinal differential protection, the fault is quickly and accurately positioned by using sampling data of a sensor, the setting of superior protection is not influenced, the protection mode is independent, and local fault isolation and self-healing can be realized.

Description

technical field [0001] The invention belongs to the technical field of distribution network fault processing, and in particular relates to a distribution network fault location method and system based on non-contact measurement. Background technique [0002] The entry of smart devices and new energy is guiding the development of traditional power grids to be intelligent and low-carbon. The simple radial distribution network is gradually transformed into a complex multi-power supply distribution network. The low-carbon distribution network adopts power electronics technology on a large scale, and the addition of new energy makes the operation mechanism, grid-connected topology and control mode of the power grid different, resulting in complex and special fault transient characteristics of the distribution network. [0003] At present, my country mainly adopts four modes of recloser feeder automation, segmental differential feeder automation, master station centralized feeder ...

AI Technical Summary

Problems solved by technology

The recloser-type fault handling and power supply recovery speed is slow, which has a great impact on the system and users. It is only suitable for simple topological lines, and it is very difficult to coordinate parameters when applied to complex networks with multiple power sources and multi-branches; And the operation mode is very sensitive, and the delay of protection action will lead to the existence of short-circuit current and voltage sag for a long time, which will aggravate the hazards of distribution station equipment and sensitive loads, and is not conducive to the protection and setting of the power grid; the centralized fault handling of the master station depends on the master station or The complexity of substations is closely related to the primary network and secondary equipment, and has high requirements for control algorithms; although intelligent distributed can overcome the defects of the above three methods, it cannot meet the selection requirements in complex networks connected to distributed power sources. performance requirements, and the application cost is high, and the maintenance efficiency is not high

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