Permanent-magnet bias fault current limiter

Abstract

The invention discloses a permanent-magnet bias fault current limiter. The invention applies permanent-magnet bias saturation technology in limiting the short circuit current of an electric line and drives electric equipment in the electric line to be safely operated. Compared with the conventional current limiting technology, the permanent-magnet bias fault current limiter has a simple structure, does not need to add any additional power supply and control device, has quick response time and self-recovery function, and has the development cost which is lower than that of other types of fault current limiters. The permanent-magnet bias fault current limiter structurally comprises a pair of mutually matched iron cores, wherein a permanent magnet is arranged at both ends of the iron cores respectively; and copper wire windings are arranged on the two iron cores respectively.

Description

technical field [0001] The invention relates to a short-circuit current limiting technology mainly used in the protection of power transmission and distribution equipment, in particular to a permanent magnet bias fault current limiter. Background technique [0002] With the rapid growth of power demand, the scale and capacity of the power grid continue to expand, resulting in an increasing level of short-circuit current in the power system, and the short-circuit current of some substations has exceeded the rated breaking capacity of existing switchgear. Excessive short-circuit current will not only cause the voltage and frequency instability of the power system, but also produce strong thermal effects and electrodynamic shocks, which will damage electrical equipment and its insulation. Furthermore, problems such as step voltage and electromagnetic interference to communication systems are also becoming more and more serious. In order to ensure the safe, reliable and stable ...

AI Technical Summary

Problems solved by technology

[0004] However, the cost of transforming the grid structure is very high; changing the operation mode will lead to a reduction in the reliability of the power system; the use of high-impedance transformers and series reactors will significantly increase network losses and reduce grid operation stability

Although the above measures can solve the short-circuit current suppression problem of the power grid to a certain extent, they will have different degrees of negative impact on the flexibility, reliability and economy of power grid operation.

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