A fault current limiter for double circuit

Abstract

The invention provides a fault current limiter for a double-circuit line, which includes a coupling winding whose end of the same name is reversely connected; the winding I of the coupling winding is connected to the I-circuit line of the double-circuit line, and the winding II is connected to the I-circuit line of the double-circuit line. II circuit; the transformation ratio of winding I and winding II is 1:1, which is used to balance the power flow of the double circuit to ensure the same current in the I circuit and II circuit; the transformation ratio of winding I and winding II is not 1 : 1, used for power flow regulation on the double-circuit line, so that the currents in the I-circuit line and the II-circuit line are different, so as to make full use of the transmission capacity of the double-circuit line. Compared with the prior art, the present invention provides a fault current limiter for double-circuit lines, which can reliably limit the short-circuit current to within within the pre-set range.

Description

technical field [0001] The invention relates to a short-circuit protection device for a power system, in particular to a fault current limiter for a double circuit line. Background technique [0002] With the rapid development of the power grid, the successive investment of large power sources in load centers, and the interconnection between large regional power grids, the excessive short-circuit current has gradually become a prominent problem in the field of stable operation of power systems. Fundamentally speaking, a reasonable grid network structure is the most effective and basic method to reduce the level of short-circuit current. At present, without changing the existing grid structure and replacing a large number of original equipment, it is possible to install a short circuit current limiter (Short Circuit Current Limiter, SCCL) or a fault current limiter (Fault Current limiter, FCL), so that the short-circuit current of the power system is limited within the allow...

AI Technical Summary

Problems solved by technology

[0004] ①: System-level measures mainly include two measures to reduce the short-circuit current level of the system, namely grid disintegration operation and busbar separate operation, but these two measures are passive current limiting measures, which reduce the stability and reliability of power system operation and flexibility, the negative impact on system operation often cannot be ignored

However, when a lightning strike occurs, it may cause simultaneous tripping of the double-circuit lines on the same tower, thereby causing a relatively large impact on the power system; therefore, a self-triggering active fault current limiter suitable for double-circuit lines on the same tower is provided to ensure the same It is particularly important for the double-circuit line of the tower to work normally

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