Anti-disturbance tripping method for unbalance protection of high-voltage capacitor with inner fuse

Abstract

The invention discloses an anti-disturbance tripping method for unbalance protection of a high-voltage capacitor with an inner fuse. The anti-disturbance tripping method for unbalance protection of the high-voltage capacitor with the inner fuse comprises the following steps: 1, obtaining an unbalance variation constant value delta 3 of unbalance protection of the high-voltage capacitor with the inner fuse; 2, determining protection delay time T according to fusing time of the inner fuse when a short-circuit fault occurs in a capacitor element; 3, when a protection device detects that the unbalance variation of the high-voltage capacitor satisfies the unbalance variation constant value delta 3 and a duration satisfies the protection delay time T, carrying out an operation of adding 1 on accumulators; 4, determining a protection action strategy for unbalance protection of the direct-current filter high-voltage capacitor with the inner fuse according to values after the operation on accumulators c1 and c2 in step 3. The anti-disturbance tripping method for unbalance protection of the high-voltage capacitor with the inner fuse has the advantages that the influence caused by disturbance to the unbalance protection of the direct-current filter high-voltage capacitor with the fuse can be limited, the protection accumulators add 1 when disturbance occurs, a protection alarm is given but tripping is not conducted, and the high-voltage side isolator of the direct-current filter or the direct-current system is prevented from being pulled open for ESOF (Emergency Switch Off).

Description

technical field [0001] The invention relates to the technical field of DC transmission control and protection, in particular to a method for unbalanced protection of a high-voltage capacitor of a DC filter with an internal fuse to prevent protection tripping due to disturbance. Background technique [0002] In DC projects, three-tuned DC filters or double-tuned DC filters are often used, such as figure 1 and 2 shown. in, figure 1 A three-tuned DC filter is shown, which includes a first tuning unit composed of a high-voltage capacitor C1 and an inductor L1 connected in series, a second tuning unit composed of a capacitor C2 connected in parallel with an inductor L2, and a second tuning unit composed of a capacitor C3 connected in parallel with an inductor L3 The third tuning unit, the first tuning unit, the second tuning unit, and the third tuning unit are connected in series in sequence, after the series connection, the first tuning unit is connected to the high-voltage b...

AI Technical Summary

Problems solved by technology

Depend on Figure 4 and Figure 5 It can be seen that the structure of the existing DC filter high-voltage capacitor is complex, and it is composed of a large number of capacitive elements connected in series and parallel.

The unbalance protection setting value setting is sensitive and the reliability is not high. Unbalance protection misoperation under non-fault conditions often occurs, that is, unbalance protection misoperation caused by disturbance, DC filter out of operation or DC outage, resulting in unnecessary Loss

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