Design of Transformer Iron Core Multi-point Earthing Automatic Protection Control System

Abstract

The multi-point grounding fault of the iron core in the operation of the transformer causes the circulation between the ground point of the iron core, which will cause the overheating of the transformer and the burning of the iron core. In this paper, according to the present most of the power transformer core grounding leads to the transformer of the external structure, design a set of iron core multipoint earthing automatic protection control system, through the automatic monitoring the change of the iron core earth current, judge whether iron core multipoint earthing, iron core multipoint earthing faults on transformers and not immediately run out, alarm inform operators at the same time, By automatically connecting the appropriate resistance value in the grounding circuit, the grounding current of the iron core is automatically limited within the set range, so as to ensure that the transformer will not cause overheating and core burning accidents under the condition that the transformer continues to operate with load. The simulation fault test of iron core multi-point grounding is carried out for the designed iron core multi-point grounding automatic protection and control system with 10 kV dry-type transformer. A treatment case of iron core multi-point grounding of 110 kV transformer using this design method is introduced to verify the effectiveness and practicability of iron core multi-point grounding automatic protection and control system.