Over-voltage protection method achieved by adoption of dry-type air-core shunt reactor combined over-voltage protection circuit

Abstract

The invention provides an over-voltage protection method achieved by the adoption of a dry-type air-core shunt reactor combined over-voltage protection circuit and belongs to the field of reactor over-voltage protection. The problems that an existing dry-type air-core shunt reactor combined over-voltage protection device recrudesces and is poor in over-voltage protection effect are solved. The cut-off current over-voltage protection is performed as follows, when a switch K of a circuit breaker is cut-off, cut-off current over-voltage occurs, i0 is set as a power frequency cut-off current value, U0 is set as a reactor power frequency voltage peak value, when t=0, the circuit breaker generates cut-off current, a resistance-capacitance protection device works, when the voltage on a protection device absorption capacitor C is not larger than the residual voltage of a lightning arrester, the resistance-capacitance protection device directly completes the cut-off current over-voltage protection on the reactor, when t=t0, the voltage on the protection device absorption capacitor C is larger than the residual voltage U1 of the lightning arrester, the lightning arrester makes action, when t=t1, the voltage on the protection device absorption capacitor C is less than or equal to the residual voltage U1 of the lightning arrester, the lightning arrester exits action, and the resistance-capacitance protection device continues to complete the cut-off current over-voltage protection on the reactor. The over-voltage protection method achieved by the adoption of the dry-type air-core shunt reactor combined over-voltage protection circuit is mainly used for reactors.

Description

Technical field [0001] The invention belongs to the field of reactor overvoltage protection. Background technique [0002] In recent years, dry-type hollow shunt reactors have been burnt out frequently, even leading to fire and combustion, which has greatly affected the safe operation of the power system. Field investigation and anatomical research show that most of the dry-type hollow shunt reactor damage is caused by the inter-turn short circuit caused by the insulation breakdown between the turns. Once the turns are short-circuited, the short-circuit turns form a huge circulating current and quickly heat up and burn the reactor. If the reactor cannot be cut out in time, it will cause fire. A large amount of data shows that when the dry-type air-core shunt reactor is cut off, there will be cut-off over-voltage and re-ignition over-voltage. Overvoltage is one of the main causes of insulation breakdown between turns. Among them, the voltage level of reignition overvoltage is hi...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the overvoltage protection effect of the existing dry-type air-core shunt reactor overvoltage protection device is poor. Overvoltage Protection Method

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