Analysis of a Misoperation Accident of the 220kv Bus Difference Backup Protection

摘要

As the power grid continues to grow, the number of components on buses is increasing. It requires bus differential protection to integrate reliability and security. This paper has introduced the inspection and handling process of a malfunction accident of 220kV microcomputer bus differential protection. The model bus differential protection was the product after six unified. The basic principle of busbar differential backup protection has been introduced. The causes of misoperation caused by microcomputer bus differential protection are analyzed from three aspects: criterion of operation bus, generation of differential current, and rationality of operation bus voltage blocking. Preventive measures and solutions for preventing malfunction of microcomputer bus differential protection has been given in this paper. Through the suggestion of changing the logic of the criterion of the running bus and the opening of the busbar voltage, the reliability of the protector has been greatly improved and the safe and stable operation of the power grid has been ensured.