A power electronic type short-circuit fault current limiter

Abstract

The invention is a power-electronic short-circuit trouble current limiter, composed by using a variable impedance to replace bypass inductance and transformer in the existing short-circuit trouble current limiter. As compared with existing techniques, it not only omits the bypass inductance but also need not design according to working conditions of common transformer because the variable impedance transformer allows the magnetic circuit to enter saturation as short-circuiting, number of turns, iron core section area of the variable impedance transformer, etc, can largely be reduced, the weight, bulk and cost are remarkably reduced, and simultaneously because of the saturation of the transformer iron core and the increase of leakage impedance, the inductance quantity of current limiting impedance can be reduced, making the overcurrent level remarkably reduced. The invention can implement the industrialized wide application of the shor-circuit current limiter to single-phase and three-phase power systems.

Description

technical field

[0001] The invention relates to a short-circuit fault current limiter for a power system. Background technique

[0002] With the increasing grid-connected capacity of the power system, the requirements for the short-circuit capacity control of the line increase accordingly. Since the current mechanical switches are not capable of high-capacity, repetitive fast circuit breaking or current limiting, various short-circuit current limiters have been proposed. A large number of short-circuit current limiter circuits are still in the experimental and experimental stage. Due to factors such as performance and cost, no short-circuit current limiter has reached the stage of industrial application.

[0003] Relatively speaking, in many short-circuit current limiter circuits, the solution using power electronic devices has the advantages of taking into account reliability, rapidity, and low cost.

[0004] The single-phase short-circuit fault current limiter disclosed ...

Examples

Embodiment Construction

[0017] Referring to Fig. 3, the single-phase power electronic short-circuit fault current limiter of the present invention includes a single-phase rectifier bridge composed of thyristors S1, S2 and diodes D1, D2, and the single-phase rectifier bridge may also be completely composed of thyristors, connected to the single-phase rectifier bridge. The reactance L2 of the DC output terminal of the phase rectification bridge and the variable impedance transformer TR2, the primary side of the variable impedance transformer TR2 is connected in series between the power grid Vs and the load R L In between, the secondary side is connected to the AC side of the single-phase rectifier bridge. When the variable impedance transformer is short-circuited, the magnetic circuit enters a saturated state.

[0018] As shown in Fig. 4, it is the example that the single-phase power electronic type short-circuit fault current limiter of the present invention is used in a three-phase power system, and t...

technical field

[0001] The invention relates to a short-circuit fault current limiter for a power system. Background technique

[0002] With the increasing grid-connected capacity of the power system, the requirements for the short-circuit capacity control of the line increase accordingly. Since the current mechanical switches are not capable of high-capacity, repetitive fast circuit breaking or current limiting, various short-circuit current limiters have been proposed. A large number of short-circuit current limiter circuits are still in the experimental and experimental stage. Due to factors such as performance and cost, no short-circuit current limiter has reached the stage of industrial application.

[0003] Relatively speaking, in many short-circuit current limiter circuits, the solution using power electronic devices has the advantages of taking into account reliability, rapidity, and low cost.

[0004] The single-phase short-circuit fault current limiter disclosed ...

Examples

Embodiment Construction

[0017] Referring to Fig. 3, the single-phase power electronic short-circuit fault current limiter of the present invention includes a single-phase rectifier bridge composed of thyristors S1, S2 and diodes D1, D2, and the single-phase rectifier bridge may also be completely composed of thyristors, connected to the single-phase rectifier bridge. The reactance L2 of the DC output terminal of the phase rectification bridge and the variable impedance transformer TR2, the primary side of the variable impedance transformer TR2 is connected in series between the power grid Vs and the load R L In between, the secondary side is connected to the AC side of the single-phase rectifier bridge. When the variable impedance transformer is short-circuited, the magnetic circuit enters a saturated state.

[0018] As shown in Fig. 4, it is the example that the single-phase power electronic type short-circuit fault current limiter of the present invention is used in a three-phase power system, and t...

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