Single-phase earth fault line selection device and multi-dimensional judgment method

Abstract

The invention provides a single-phase earth fault line selection device and a multi-dimensional judgment method. The device comprises a circuit breaker body, the input end of a three-phase current acquisition module is connected with a three-phase current transformer, one path of the output end is connected with the input end of a zero-sequence current module, and one path is connected with a corresponding input port of a central processor; the input end of the three-phase voltage acquisition module is connected with a three-phase voltage transformer, one path of the output end is connected with the input end of a zero-sequence voltage module, and one path is connected with a corresponding input port of the central processor; the output ends of the zero-sequence current module and the zero-sequence voltage module are connected with corresponding input ports of the central processort; the output end of the central processor is connected with the input end of a communication module; theoutput end of the communication module is connected with a display control terminal and the communication input end of the breaker body in parallel. The device can effectively improve the accuracy ofsteady-state zero-sequence over-current protection, can be applied to equipment such as a pole-mounted circuit breaker and a ring main unit to judge a single-phase earth fault, and can remotely or locally control opening and closing.

Description

technical field [0001] The invention relates to the technical field of pole-mounted circuit breaker detection, in particular to a single-phase ground fault line selection device and a multi-dimensional judgment method. Background technique [0002] When a single-phase ground fault occurs in a small-current grounding system, the ground fault current is small, and the magnitude of the zero-sequence current of each line is affected by the structure and parameters of the power grid, the transition resistance of the ground fault point, and the neutral point grounding method, resulting in zero-sequence It is not accurate enough to select the fault line due to the current overcurrent. Contents of the invention [0003] The purpose of the present invention is to provide a single-phase ground fault line selection device and multi-dimensional judgment method, which can effectively improve the accuracy of steady-state zero-sequence overcurrent protection, and can be applied to equipm...

AI Technical Summary

Problems solved by technology

[0002] When a single-phase ground fault occurs in a small-current grounding system, the ground fault current is small, and the magnitude of the zero-sequence current of each line is affected by the structure and parameters of the power grid, the transition resistance of the ground fault point, and the neutral point grounding method, resulting in zero-sequence Fault line selection is not accurate enough due to overcurrent

Images