Method for evaluating risk of short circuit and damage of transformer

Abstract

The invention relates to a method for evaluating the risk of short circuit and damage of a transformer. The method is characterized by comprising the following steps: (1) evaluating the degree of the short circuit and damage of the transformer from short-circuit current according to a formula; (2) calculating the probability of tripping of single main transformer circuit every year according to a formula; (3) calculating the proportion of damaged transformers in recent ten years to transformers tripped at outlets according to a formula; (4) calculating the probability of the short circuit and damage at the low-voltage side of single transformer according to a formula; (5) evaluating the quantity P of the transformers damaged by short circuit every year according to a formula. The method is wide in application range, high in reliability and low in cost, can be used for evaluating the risk of the short circuit and damage of the transformer, and can be applicable to evaluation on the risk of the short circuit and damage of multiple transformers with different voltage levels and different cooling modes.

Description

technical field [0001] The invention belongs to the field of transformer operation detection and maintenance, and in particular relates to a method for evaluating the risk of transformer short circuit and damage. Background technique [0002] The transformer is the core of the power supply system, and the reliability of its operation has a great impact on the safety of the power system. However, with the increasing capacity of the current power grid, the short-circuit capacity of the system also increases. At the same time, the operating environment of the incoming and outgoing lines of the substation is not optimistic, and various overvoltages occur from time to time. In recent years, due to various reasons, accidents of damage to large-scale transformers caused by external short-circuits have occurred frequently. Many transformers have winding deformation and damage when the short-circuit current and short-circuit time are far below the level required by the national stand...

AI Technical Summary

Problems solved by technology

However, with the increasing capacity of the current power grid, the short-circuit capacity of the system also increases. At the same time, the operating environment of the substation's incoming and outgoing lines is not optimistic, and various overvoltages occur from time to time.

In recent years, due to various reasons, accidents of damage to large-scale transformers caused by external short-circuits have occurred frequently. Many transformers have winding deformation and damage when the short-circuit current and short-circuit time are far below the level required by the national standard and the manufacturer's commitment. Some new The external short circuit of the transformer put into operation will be damaged once or twice