Transformer heavy gas protection external tripping circuit

Abstract

The invention discloses an external tripping circuit for heavy gas protection of a transformer. In the circuit, one end of a normally open contact of a protection tripping outlet relay is connected with the anode of a DC power supply, and the other end is connected with one end of a protection tripping pressure plate, the other end of the protection tripping pressure plate is connected with one end of an auxiliary normally open contact of a circuit breaker, and the other end of the auxiliary normally open contact of the circuit breaker is connected with one end of an opening coil, and the other end of the opening coil is connected with the negative electrode of the DC power supply. A gas relay is installed on a pipeline of a transformer body oil tank and an oil conservator, and when the interior of the transformer breaks down, a heavy gas relay contact is closed. One end of the heavy gas relay contact is connected with the anode of the DC power supply, and the other end is connected with the other end of the protection tripping pressing plate. According to the transformer heavy gas protection external tripping circuit, when an internal fault occurs in a user side transformer, the superior power grid circuit breaker trips to cut off power supply of the transformer, the accident range is prevented from being further expanded, and the safety and reliability of a power supply system are improved.

Description

technical field [0001] The invention relates to the technical field of transformer protection and control, in particular to an external tripping circuit for transformer heavy gas protection. Background technique [0002] Transformer is an important electrical equipment in the power system. Under normal circumstances, it can convert one voltage and current AC power into another voltage and current AC power of the same frequency, and provide power users with power at a suitable voltage level. . The gas protection is the main protection for the internal fault of the transformer, which can effectively reflect the internal fault of the transformer. Gas protection includes light gas protection and heavy gas protection. Light gas protection acts on the signal, heavy gas acts on the trip. In the prior art, the contact of the transformer gas relay is connected to the relay protection device through the DC power supply. When a fault such as a short circuit occurs inside the transfo...

AI Technical Summary

Problems solved by technology

The regulations stipulate that oil-immersed transformers above 800kVA must be equipped with gas protection, but some small-scale substations or power distribution rooms are not equipped with DC power supplies or protection devices on site. The transformer cannot cut off the power supply, which further aggravates the failure of the transformer, expands the scope of the accident, and affects the safety and reliability of the power supply system.

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