On-load tap-changer inter-stage short-circuit fault early warning method, device and storage medium

Abstract

The invention discloses an on-load tap-changer interstage short-circuit fault early warning method, comprising: collecting three-phase currents on the winding side of a transformer to be tested connected to the on-load tap-changer; calculating the real-time effective value of the three-phase currents Amplitude; calculate the unbalance rate of the three-phase current according to the amplitude of the real-time effective value of the three-phase current; and output an alarm signal when the unbalance rate of the three-phase current is greater than a preset early warning threshold. The invention can give early warning to the internal fault of the transformer caused by the on-load tap changer, and reduce the equipment damage caused by the huge energy generated by the fault current in the delay process. The invention also discloses an on-load tap changer interstage short-circuit fault early warning device and a storage medium.

Description

technical field [0001] The invention relates to the technical field of on-load tap changers, in particular to a method, device and storage medium for early warning of short-circuit faults between stages of on-load tap-changers. Background technique [0002] The on-load tap-changer is a voltage regulating device used to change the tap connection position of the transformer winding. The reliability of the on-load tap-changer is very important to the normal operation of the transformer. Once the on-load tap-changer fails, it will directly cause the transformer to stop operating, and even cause the transformer to explode or catch fire in severe cases. In recent years, there have been many transformer explosions and fire failures caused by abnormalities in the shifting process of on-load tap-changers in the power grid, which has brought a great impact on the safe and stable operation of the power system, and has also caused serious damage to the power sector and society. Big los...

AI Technical Summary

Problems solved by technology

by figure 1 For example, where t 0 ’ is the time when the fault current appears when the on-load tap-changer inter-stage short-circuit fault occurs, Δt 1 ’ is the starting time of differential protection, Δt 2 ’ is the tripping time of the differential protection outlet, where, Δt 2 'Usually between 20 and 40 ms, that is, there is a certain delay in the differential protection method in the prior art; during this delay, the fault current generated by the short circuit between the stages of the transformer tap changer will generate huge energy, resulting in Equipment damage

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