Direct current limiter and application thereof

Abstract

The invention discloses a direct current limiter and an application thereof. The direct current limiter comprises a current limiting unit, an energy absorption unit and a direct-current circuit breaker unit, wherein the current limiting unit is composed of a three-phase coupling reactor, a pre-charging capacitor, a smoothing reactor, a small direct-current circuit breaker and a line, and when a short-circuit fault occurs, the coupling reactor is equivalent to a large inductor to be connected into a main loop in series, and a voltage opposite to the power supply voltage is generated on the inductor to limit the fault current and reduce energy absorption of a lightning arrester; the energy absorption unit is formed by connecting a diode and a resistor in series and can inhibit stored energyof an inductive element in the line from being transmitted to the lightning arrester; the direct-current circuit breaker unit comprises a direct-current circuit breaker and a lightning arrester, the circuit breaker cuts off the fault current, and the lightning arrester absorbs energy stored by the inductor. The hybrid direct current limiter provided by the invention realizes control of the fault current, energy absorption limitation of the lightning arrester and parallel connection of capacitors to reduce the capacity, and is low in manufacturing cost.

Description

technical field [0001] The present invention relates to the field of DC current limiters, more specifically, to a DC current limiter and its application. Background technique [0002] DC transmission is an effective measure for distributed green energy to connect to the grid, and DC transmission also has the advantages of long transmission distance, small loss, and large transmission capacity, which has important research significance. [0003] With the development of DC transmission, the voltage level of the DC grid continues to increase, which increases the transmission efficiency of the grid and the reliability of the grid, but also makes the short-circuit current continue to increase, increasing the DC circuit breaker (DCCB) Breaking pressure makes it difficult to shut down the DC side circuit breaker. If the DC side fails to remove the fault in time, the AC side circuit breaker on the converter side needs to perform related actions to block the converter valve group to ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the defects of the prior art, the purpose of the present invention is to solve the technical problem that the existing DC circuit breaker is difficult to break the large fault current and the high energy absorption of the arrester is caused by breaking the large fault current

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