Hybrid direct-current current-limiting breaker

Abstract

A hybrid direct-current current-limiting breaker comprises a rapid mechanical switch B, an IGBT module G, a thyristor module T1, a thyristor module T2, a current limiter FCL, an inductor L1, a capacitor C1 and a lightning arrester MOV. The rapid mechanical switch B is connected between a connecting point 1 and a connecting point 5, the IGBT module G is connected between a connecting point 2 and the connecting point 5, the rapid mechanical switch B is connected with the IGBT module G in series, the thyristor module T2 is connected between the connecting point 1 and the connecting point 2, both the thyristor module T1 and the current limiter FCL are connected between the connecting point 2 and a connecting point 3, and the thyristor module T1 is connected with the current limiter FCL in parallel; and the capacitor C1 is connected between the connecting point 1 and a connecting point 4, the inductor L1 is connected between the connecting point 3 and a connecting point 4, the capacitor and the inductor are connected in series, and the lightning arrester MOV is connected between the connecting point 1 and the connecting point 3. During stable operation of a power grid, the breaker presents low impedance, and influence on the power grid is small; and when a fault occurs in a direct current transmission line, fault current limiting and cutoff of the faulty line can be rapidly realized.

Description

technical field [0001] The invention relates to a hybrid DC current-limiting circuit breaker topology, in particular to a high-voltage DC current-limiting circuit breaker topology for a flexible DC grid. Background technique [0002] DC circuit breaker is one of the key equipment to ensure the stable, safe and reliable operation of DC power transmission and distribution system and DC grid system. The difference from the AC system is that the current of the DC system does not have a natural zero-crossing point, so the natural zero-crossing point of the current cannot be used in the DC system to shut down like the AC system, so the breaking of the DC fault current has always been a problem worth studying. subject. [0003] In order to quickly and effectively isolate DC faults, ensure the safe and stable operation of DC grid-related equipment, and minimize the impact of faults on the operation of AC and DC systems, it is necessary to use high-voltage DC circuit breaker technol...

AI Technical Summary

Problems solved by technology

The difference from the AC system is that the current of the DC system does not have a natural zero-crossing point, so the natural zero-crossing point of the current cannot be used in the DC system to shut down like the AC system, so the breaking of the DC fault current has always been a problem worth studying. subject

The on-state loss of traditional mechanical DC circuit breakers is low, but affected by the time required for oscillation and the breaking speed of conventional mechanical switches, it is difficult to meet the requirements of DC systems for quickly breaking fault currents; solid-state DC circuit breakers need to use more devices in series, making them Large on-state loss and high cost

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