Sequence component longitudinal direction protection method of six-phase power transmission line

Abstract

The invention belongs to the technical field of relay protection, and relates to a sequence component longitudinal direction protection method of a six-phase power transmission line. The method comprises the following steps of: collecting six-phase current and voltage data through protecting a current transformer and a voltage transformer at the mounting part; respectively converting into six sequence voltage components and six sequence current components; calculating a reverse sequence fault component and a positive sequence fault component; determining movement criteria of T1, F0 and F1 fault components, and if more than one of the three criteria is determined to be a positive direction fault, protecting the generation of the determined positive direction short circuit of the side; protecting a determined reverse direction generation circuit of the side, if the three criteria are all of reverse directions; protecting tripping operation of movements if the side and the opposite side are both determined to be the positive direction short circuit; and protecting failure to actuate if one side of the two sides are determined to be the reverse direction short circuit or two sides are both determined to be reverse direction short circuits. According to the invention, the criteria are simple, the protection method is easy to realize and can reflect all faults of a six-phase system, and the method is an ideal main protection scheme.

Description

technical field [0001] The invention belongs to the technical field of six-phase power transmission in electric power systems, and in particular relates to a longitudinal relay protection scheme for ultra-high voltage, ultra-high voltage and high-voltage six-phase power transmission lines. Background technique [0002] Six-phase power transmission is a kind of multi-phase power transmission. The typical schematic wiring is shown in Figure 1, which consists of four transformers and six-phase transmission lines. The parallel three-phase system is converted into a six-phase system through two transformers, and the six-phase system is converted into a three-phase system through two transformers at the other end. The wiring modes of the four transformers are: D, y11, Y, d1, D, y1, Y, d11. The six phases of the six-phase transmission line are A, B, C, D, E and F, and are generally arranged in a regular hexagon. The phase angle difference between two adjacent phases (such as A and...

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Problems solved by technology

Literature [1] proposed a longitudinal protection criterion based on half-positive, half-negative, and half-zero-sequence components. The shortcoming is that it cannot judge six-phase faults, and it needs to switch to other criteria when six-phase faults occur; literature [1] 2] A phase differential protection criterion based on half-positive, half-negative, and half-zero-sequence components is proposed, but the operating characteristics are affected by the length of the line. When the length of the line reaches a certain value, cameras on both sides need to trip

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