Energy quick transfer-based hybrid direct current super-conductive current limiter

Abstract

The invention discloses an energy quick transfer-based hybrid direct current super-conductive current limiter, and belongs to the technical field of electrical engineering. The energy quick transfer-based hybrid direct current super-conductive current limiter comprises two inductive coils, a direct current quick switch, a bypass resistor, a fixed value resistor, and metal oxide lightning arresters, wherein the two inductive coils are connected in parallel; the two inductive coils are wound by super-conductive wires with the same number of turns and consistent structures, and the magnetic fluxes of the coils are coupled forwardly; the direct current quick switch is connected with the super-conductive inductive coils in series as a whole to form a series branch; the bypass resistor is connected with the two ends of the series branch in parallel; the fixed value resistor is connected with the two ends of the quick switch in parallel; and the two metal oxide lightning arresters are connected at the two ends of the two inductive coils in parallel respectively. The current limiter disclosed by the invention can provide a super-conductive-state and resistance-loss-free smoothening electric reactance for a power transmission line at a normal state of a direct current system, can rapidly and effectively suppress peak of a short circuit current when the direct current system suffers from a monopole grounding fault or a two-stage short-circuit fault, and also can protect safe and stable operation of the super-conductive inductive coils.

Description

technical field [0001] The invention belongs to the technical field of electric engineering, and more precisely, the invention relates to a fault current limiter suitable for short-circuit protection of power systems. Background technique [0002] To build the Energy Internet, one of the important methods that can be selected for future transmission network construction is voltage source high-voltage direct current transmission (VSCHVDC). The problem of rapid disconnection of DC short-circuit fault current is one of the key technical issues to be solved urgently for VSC-HVDC power grids. [0003] At present, although high-voltage DC circuit breakers are considered to be one of the effective ways to solve the problem of short-circuit faults in DC power grids, with the continuous development of power grids and the continuous increase of transmission capacity, the level of short-circuit current continues to increase. When the short-circuit current exceeds When the interrupting ...

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Problems solved by technology

[0008] In the DC system, the resistive current limiter uses the quench characteristics of superconducting materials to realize automatic triggering, automatic current limiting, and rapid response when a fault occurs. Weak, it is difficult to control the quench process, which reduces the reliability of the equipment, and the self-recovery time is long; in the DC system, the inductive current limiter automatically limits the current when it fails, responds quickly, and can well limit the peak value of the short-circuit current. The disadvantage is the lack of resistive components, the short-circuit current tends to be stable before the fault is removed, and the inductance of the current limiter cannot suppress the steady-state short-circuit current

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