Protective circuit for switching over-voltage protection of dry air reactor

Abstract

The invention discloses a protective circuit for switching over-voltage protection of a dry air reactor, relates to an over-voltage protective circuit for the dry air reactor, and solves the following problems in the traditional reactor over-voltage protection: the capacitance volume is large and the production cost is high when a resistance-capacitance absorption circuit is singly used, and dispersibility of gap breakdown voltage is increased and service life of protective gap is reduced due to frequent actions of the protective gap when a gap protector is singly used. The protective circuit can be satisfied through choosing proper element parameters according to cut-off current; when the cut-off current is lower, a resistance-capacitance absorption device controls over-voltage amplitude values at two ends of the reactor to prevent the over-voltage amplitude values from reaching the breakdown voltage of the protective gap, the protective gap is in a disconnection state, and the reactor and respective resistance-capacitance elements form an RLC (Radio Link Control) oscillation circuit; when the cut-off current is higher, the over-voltage amplitude values at two ends of the reactor are higher, the protective gap is broken down, and a capacitor and a protective resistor thereof are short out; the protective circuit for the switching over-voltage protection of the dry air reactor is applied to the reactor protection field.

Description

technical field [0001] The invention relates to an overvoltage protection circuit of a dry-type air-core reactor. Background technique [0002] In the ultra-high-voltage large-capacity power grid, in order to compensate the reactive power of the grid, a certain number of reactors are required to be installed. Dry-type air-core reactor adopts multi-package and winding structure. Compared with iron-core reactor, it has technical advantages such as low price, simple structure, light weight, linear reactance value, low loss, and convenient maintenance. Since the 1990s, dry-type air-core reactors have been widely used in power systems. With the increase in the number and time of operation of dry-type air-core reactors, accidents have gradually increased, and they often catch fire, which has greatly affected the safe operation of the power system. Field investigation and anatomical research show that most of the dry-type air-core reactor faults are caused by inter-turn short cir...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims to solve the problem that in the traditional reactor overvoltage protection, when the resistance-capacitance absorption circuit is used alone, the required capacitor volume is large and the cost is high. When the gap protection device is used alone, the frequent action of the protection gap will increase the dispersion of the gap breakdown voltage The problem of reducing the life of the protection gap, the invention provides a protection circuit for dry-type air-core reactor switching overvoltage protection

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