Dry type air-core reactor turn-to-turn short circuit protection method

Abstract

The invention discloses a dry type air-core reactor turn-to-turn short circuit protection method, and relates to a short circuit protection method. There is a big dead zone in dry type air-core reactor two-stage overcurrent protection, and a reactor is already serious in burning loss when a reactor protection action is carried out. The dry type air-core reactor turn-to-turn short circuit protection method comprises the steps of collecting phase current and line voltage of a dry type air-core reactor; calculating the real-time remaining reactance ratio according to rated phase current, rated line voltage and the acquired phase current and line voltage of the dry type air-core reactor; and judging whether the dry type air-core reactor has a turn-to-turn short circuit or not and the seriousness of the turn-to-turn short circuit according to the real-time remaining reactance ratio. Compared with overcurrent protection at present, the technical scheme can greatly reduce the protection dead zone, shorten the discovery time of the turn-to-turn short circuit of the dry type air-core reactor and improve the safe operation capability of the dry type air-core reactor and neighboring equipment.

Description

technical field [0001] The invention relates to a short-circuit protection method, in particular to a dry-type air-core reactor turn-to-turn short-circuit protection method. Background technique [0002] As an important voltage regulating device, dry-type air-core reactors are widely used in power systems. For dry-type air-core reactors with circuit breakers at the head end, their protection is generally equipped with two-stage overcurrent protection. Theoretical analysis and simulation verification found that there is a large dead zone in the two-stage overcurrent protection. When the reactor protection operates, the reactor burnout is very serious. When one phase of the reactor is composed of two dry-type air-core reactors connected in series, it may happen that a single reactor is completely burned out but the protection does not move. Under the rated voltage, the inter-turn short circuit is more than 50%, and the protection will act to remove the fault. At this time, th...

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Problems solved by technology

The minimum action setting value of the reactor protection is 1.5Ie. When two reactors are put into use at the same time or the 110kV bus voltage is low due to system reasons, one of the reactors of a certain phase has an inter-turn short circuit, even if the inter-turn short circuit is 100%. The fault current is also less than 1.5Ie, that is, the protection will not operate! Seriously affect the stability, safety and reliability of work

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