Novel self-energy type liquid metal current limiter and method

Abstract

The invention provides a novel self-energy type liquid metal current limiter and a current limiting method. The novel self-energy type liquid metal current limiter is characterized in that liquid metal carries out self-constriction arcing under the fault current condition and is gasified under the effect of electric arcs, generated powerful metal steam is continuously accumulated and finally pushes a movable insulation draw plate arranged between insulation baffles to upwards slide, the electric arcs between the insulation baffles and the draw plate are rapidly extruded into a slit and are further lengthened, then the voltage of the electric arcs is rapidly increased, and the fault current is further limited. The novel self-energy type liquid metal current limiter is simple in structure and particularly suitable for limiting the fault current of alternating-direct current systems in the medium-low voltage field, and burdens of various electrical devices such as breakers can be assisted to be relieved.

Description

technical field [0001] The invention relates to electrical switchgear, which is suitable for limiting the fault current of AC and DC systems in the field of medium and low voltages, and in particular relates to a novel self-energy liquid metal current limiter and its method. Background technique [0002] With the increase of power system capacity year by year, the short-circuit capacity and short-circuit current level of the power grid are also increasing, which has become an important problem restricting the operation and development of the power grid. Therefore, research on effective short-circuit current limiting devices to limit the short-circuit capacity of the power system and improve the reliability of the power system has become an urgent issue for the safe and stable operation of the power system and the construction and development of power systems in my country. So far, the technologies applied to short-circuit current limiting mainly include: series current-limit...

AI Technical Summary

Problems solved by technology

However, the application technology of superconducting materials for high-power applications is still immature and the reliability is poor. At the same time, it takes a long time for superconductors to return to the superconducting state, so it is generally difficult to meet the requirements of automatic reclosing and other aspects, and liquid nitrogen is also required for recovery. And other auxiliary refrigerants and refrigeration equipment, the additional loss is large, etc.

[0006] The current-limiting fuse is currently the only commercialized fault current limiter. The short-circuit current can be forcibly limited before reaching the first peak value by using the rapidity of the fuse. For example, the patent number is 200410025999.1, and the patent name is 'Large capacity short The patented current-limiting fuse of the current breaker completes the breaking of large overload current and short-circuit current, but the fuse is a single action, which reduces the automation level of the system operation. For grids with complex structures, the selectivity of protection is sacrificed

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