A system and method for overcurrent protection system and method for arc protection acceleration transformer complex voltage blocking overcurrent protection

Abstract

The invention discloses a composite-voltage latch-up over-current protection system and method of an arc-protection acceleration transformer. The system is composed of a setting value input circuit, a conversion decoding circuit, an arc protection signal input circuit, a processor and an output circuit. Output terminals of the setting value input circuit, the conversion decoding circuit and the arc protection signal input circuit are connected with the input terminal of the processor; the output terminal of the processor is connected with the input terminal of the output circuit; and the output terminal of the output circuit outputs a protection output quantity. Meanwhile, the invention also discloses a method of the system. Therefore, the acting time of composite-voltage latch-up current protection can be shortened; the short-circuit impact on the transformer in a fault state can be reduced; and the damages on the transformer by the short-circuit fault can be reduced.

Description

technical field [0001] The invention relates to an arc protection acceleration transformer complex voltage blocking overcurrent protection system and method, and belongs to the technical field of transformer protection. Background technique [0002] The transformer is the key equipment of the power grid, which undertakes the important task of transforming voltage and transmitting electric energy, and is an indispensable and expensive asset in the substation. Once the transformer in the substation fails or is damaged, it will cause loss of part of the load, and the spare transformer will be under heavy load operation, which will increase equipment loss and depreciation, and the whole substation will be paralyzed and unable to operate. Especially for transformers with a voltage level of 220kV and above, due to the huge size of the equipment and inconvenient transportation, the cycle of overhaul and replacement of the transformer is long, and once a failure or damage occurs, hu...

AI Technical Summary

Problems solved by technology

The protection signals of the first and second sections are repeated with the signals sent by the arc protection. In this case, the protection configuration of the first and second sections is meaningless, and the tripping protection signals of the circuit breakers on each side of the third section are extended. The sending time of the transformer will make the transformer withstand the impact of high current for a long time, which may aggravate the damage of the transformer

In addition, under normal circumstances, the complex voltage blocking overcurrent protection is coordinated with the third-stage protection, and its time limit is set at about 1.5s. If the time limit of the first and second stage protection is increased, it may exceed the "transformer external short-circuit fault, short-circuit current greater than the thermal stability current of the winding on either side, the transformer over-current protection action time should not exceed the requirement of 2s”

[0005] In short, the existing transformers equipped with arc protection and complex voltage blocking overcurrent protection, when the circuit breaker on the medium and low voltage side fails and cannot trip normally, the existing protection system takes a long time to remove the fault, and it is difficult to meet the requirements of the transformer protection action time. Good protection for transformers

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