Distribution line adaptive protection method and system based on traveling waves

Abstract

The present invention discloses a distribution line adaptive protection method and system based on traveling waves, belonging to the technical field of line protection. At measurement points, far awayfrom a bus, of a fault line, the fault phase initial current traveling waves of the single-phase grounding faults are large, and the non-fault phase is zero; at measurement points, close to the bus,of the fault line, the fault phase initial traveling wave amplitude of the single-phase grounding faults are twice of the non-fault phase, and the polarity is opposite. At the measurement points, faraway from the bus, of the fault line, the fault phase initial current traveling waves of the two-phase grounding faults are large, and the non-fault phase is zero; and at the measurement points, closeto the bus, of the fault line, the initial current traveling waves of the fault phase and the non-fault phase of the two-phase grounding faults have no obvious features. The distribution line adaptive protection scheme can perform accurate and reliable motions for all the types of short-circuit faults. The propagation of the initial traveling waves cannot be influence by a grounding resistance condition, and therefore, the protection scheme can respond to the high-resistance grounding faults.

Description

technical field [0001] The invention relates to a traveling wave-based self-adaptive protection method and system for power distribution lines, belonging to the technical field of line protection. Background technique [0002] A phase-to-earth fault in a system with a non-effectively grounded neutral point is characterized differently from other short-circuit faults. Single-phase grounding does not constitute a short-circuit loop, and there is no significant change in power frequency current. The overcurrent protection applicable to other short-circuit faults cannot protect single-phase grounding. This paper proposes a single-phase ground fault identification algorithm based on traveling wave characteristics. The proposed algorithm can accurately identify single-phase ground faults and non-single-phase ground faults. And on this basis, a distribution line protection scheme that can adapt to all short-circuit types is formed. [0003] Single-phase ground faults account for ...

AI Technical Summary

Problems solved by technology

2. Line selection technology only deals with single-phase ground faults, not for two-phase faults and three-phase faults; 3. Failure to handle single-phase ground faults in time may lead to overvoltage in the system

However, the research in the literature only focuses on single-phase ground faults and does not involve other faults on distribution lines, so in practical applications, the proposed protection needs to cooperate with traditional overcurrent protection

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