Detecting method and detecting system for multipoint earthing of voltage second loop neutral conductor network

Abstract

The invention discloses a detecting method for multipoint earthing of a voltage second loop neutral conductor network. The method comprises the steps: selecting at least one current injecting point from the voltage second loop neutral conductor network, and injecting a first current from the at least one current injecting point; detecting a current near a permanent earth point in the voltage second loop neutral conductor network to obtain a second current; comparing a difference value of the second current and the first current with a preset threshold value, and if the difference value is within the preset threshold value, confirming that the multipoint earthing exists in the voltage second loop neutral conductor network; and positioning each earthing point according to a topological structure of the voltage second loop neutral conductor network. The invention further discloses a detecting system for the multipoint earthing of the voltage second loop neutral conductor network. According to the scheme, whether the multipoint earthing exists in the voltage second loop neutral conductor network or not can be detected.

Description

technical field [0001] The present application relates to the field of electric power technology, in particular to a method and system for detecting multi-point grounding of a voltage secondary circuit neutral line network. Background technique [0002] In the field of power technology, equipment that produces, transforms, transmits, and distributes electrical energy (such as generators, transformers, and transmission and distribution power lines, etc.), as well as equipment that uses electrical energy (such as motors, electric furnaces, relay protection and control devices, etc.), Even the same whole composed of energy management system is called power system. The composition of the power system can be divided into a primary system (or primary loop) and a secondary system (or secondary loop) according to functional differences: the former is responsible for the transmission and distribution of electric energy, and the latter is used to monitor the primary system (or primary...

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Problems solved by technology

[0003] In order to ensure the normal operation of the voltage secondary circuit, the neutral line network of the voltage secondary circuit must be permanently grounded, and only have this grounding point. If there are other grounding points except the permanent grounding point, it will cause the line Accidents such as zero-sequence protection reverse direction misoperation, joint transformer protection misoperation and longitudinal protection misoperation have caused major impacts

[0004] However, although the grounding point of the neutral line network of the voltage secondary circuit is so important for the secondary voltage circuit, in the actual application process, except at the beginning of the wiring of the voltage secondary circuit, multi-point grounding can be avoided by paying attention to the line connection In the process of power grid operation, there has not been a good detection method for multi-point grounding of the neutral line of the voltage secondary circuit

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