A protection circuit for dry-type air-core reactor switching overvoltage protection

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 power grid, a certain number of reactors are required to be installed. Dry-type air-core reactor adopts multi-encapsulated and wound structure type. Compared with iron-core reactor, it has the technical advantages of 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 of the number of dry-type air-core reactors in operation and the time of operation, accidents have gradually increased, and they often catch fire, which has a great impact on the safe operation of the power system. Field investigations and anatomical studies show that most of the faults of dry-type air-core reactors ...

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