High-voltage DC current limiter based on coupled reactors

Abstract

The invention provides a high-voltage DC current limiter based on coupled reactors, comprising a current limiting module, an energy absorbing module and a DC circuit breaker module. The current limiting module is composed of coupled reactors, a smoothing reactor, a pre-charged capacitor and a thyristor. The coupled reactors are reversely coupled and have high coupling coefficient. Under normal operation, the currents on the two sides are the same, the coupled reactors have small magnetic flux and small equivalent inductance, and the influence on the system is small. When a fault occurs, the thyristor is triggered to be turned on, the pre-charged capacitor and the coupled reactor L2 oscillate to produce a reverse current to make the currents on the two sides of the coupled reactors unequal,and the coupled reactors have large equivalent inductance which limits the current together with the smoothing reactor. The energy absorbing module can restrain the transfer of the energy of the coupled reactors and the smoothing reactor to an arrester. The DC circuit breaker module includes a circuit breaker and an arrester, the circuit breaker breaks the fault current, and the arrester absorbsthe energy stored by inductance. Fault current limitation and arrester energy absorption limitation are realized.

Description

technical field [0001] The invention belongs to the field of high-voltage direct-current current limiters, and more specifically relates to a high-voltage direct-current current limiter based on coupling reactors. Background technique [0002] Since the distributed energy access to the DC grid has little impact on the DC of the system, DC transmission is an effective measure to solve the problem of connecting green renewable energy to the grid. Compared with AC transmission, DC transmission has the advantages of long transmission distance and large transmission capacity. , many countries around the world have carried out related construction. The flexible DC transmission, compared with the traditional DC transmission at both ends, because of its long transmission distance, small loss, independent control of reactive power / active power, no need for filtering and reactive power compensation equipment, it can supply power to passive loads, and the voltage is extremely high when...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the defects or improvement needs of the prior art, the present invention provides a high-voltage DC current limiter based on a coupling reactor, aiming at solving the difficulty in breaking a large fault current in the prior art and the arrester absorption caused by breaking a large fault current. high technical issues

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