Interturn Fault Identification Method of Phase Control Reactor Based on Third Harmonic and Active Power Loss

Abstract

The invention discloses a phase-controlled reactor turn-to-turn fault identification method based on third harmonic and active loss. A special triangular wiring mode of a phase-controlled reactor is utilized, characteristics such as significant or drastic increase of the active loss of a single side phase, destroy of the symmetry of the third harmonic current in the angle, remarkable increase of the third harmonic current outside the angle and remarkable amplification of the third harmonic outside the angle by a fifth filter and a seventh filter are monitored, bus grounding signals generated after a turn-to-turn fault of the phase-controlled reactor can be used as auxiliary identification and judgment signals, so that the turn-to-turn fault of the dry type hollow phase-controlled reactor can be rapidly and reliably identified. According to the method, the turn-to-turn short circuit fault is sensitively discovered by utilizing various different judgment conditions which can be independent of one another or combined with one another, accurate identification and fault phase determination can be carried out at the initial stage of the turn-to-turn fault, alarm can be timely carried out, a power supply can be timely cut off, the phase-controlled reactor is prevented from firing and burning, and expansion accidents such as bus short circuit are avoided.

Description

technical field [0001] The invention belongs to the field of on-line fault monitoring and protection of electrical equipment in a power system, and in particular relates to a phase-controlled reactor turn-to-turn fault identification method based on third-order harmonics and active power loss. Background technique [0002] In static var compensation system (SVC), in order to obtain smooth and adjustable inductive reactive power (inductive current) output, thyristor valve-controlled reactors or phase-controlled Wave inductive reactive capacity output. Due to the large number of 3rd, 5th, 7th and 11th harmonics in the current of the reactor controlled by the thyristor valve triggered by the phase angle, the current large-capacity TCR outdoor layout usually adopts 6 three-phase groups stacked up and down or placed horizontally The typical faults of dry-type air-core reactors are the same as other dry-type air-core parallel reactors or series reactors, mainly including inter-st...

AI Technical Summary

Problems solved by technology

This kind of fault current is the internal short-circuit circulation between coil winding turns. Even if the inter-turn short-circuit fault continues to develop and expand until the inductance completely disappears, due to the special wiring form of TCR and the adjustment and control characteristics of the thyristor valve switch, the corner inside and outside corner The current of the circuit will not increase sharply. Conventional differential and overcurrent protection and other existing protection methods cannot detect the existence of faults, nor can they achieve timely, reliable, rapid detection and protection.

[0004] At present, there is no effective protection method suitable for dry-type air-core TCR inter-turn short circuit faults. Other shunt reactors or series reactors such as dry-type air-core have invented mature and available monitoring and protection methods.

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