Current transfer device and method suitable for hybrid DC breaker

Abstract

The invention discloses a current transfer device and method suitable for a hybrid DC breaker. The device comprises a precharging capacitor, a rapid-conduction switch, a primary-side coil and a secondary-side coil; and the precharging capacitor and the primary-side coil form an electric circuit through the rapid-conduction switch, and two ends of the secondary-side coil are taken as leading-out terminals as the device and then are connected to the hybrid DC breaker. When the hybrid DC breaker enables a current to be provided or be cut off, the current transfer device and method provided by the invention can guarantee a branch current of a mechanical switch to be reliably transferred to a branch of a solid DC breaker, and, finally, the current is provided or cut off by the solid DC breaker. Compared with the prior art, the current transfer device and method has the advantages of simple implementation and low cost, and can reduce operation loss of the hybrid DC breaker when normal operation is performed.

Description

technical field [0001] The invention relates to the technical field of electric power equipment, in particular to a current transfer device and method suitable for a hybrid DC circuit breaker. Background technique [0002] The rapid development of multi-terminal DC transmission systems based on voltage source converter stations urgently requires DC circuit breakers to quickly isolate faulty lines on the DC side to ensure reliable power supply from each converter station to normal lines. At present, there are mainly two realization methods of DC circuit breakers: manual zero-crossing type and hybrid type DC circuit breaker. Among them, the hybrid DC circuit breaker has attracted widespread attention due to its high controllability. [0003] The hybrid DC circuit breaker mainly includes fast mechanical switch branch and solid state DC circuit breaker branch. When the line is normal, the current is conducted by the mechanical switch branch; once a line fault is detected, the ...

AI Technical Summary

Problems solved by technology

In this scheme, the auxiliary electronic switch conducts current for a long time, which leads to an increase in the operating loss of the hybrid DC circuit breaker, and a heat dissipation device needs to be installed for it; the auxiliary electronic switch needs to be composed of multiple fully-controlled devices connected in series and parallel. It has the ability to turn on and off the bidirectional current, and its cost is relatively high; the turn-off of the auxiliary electronic switch and the turn-on of the solid-state DC circuit breaker need to be reasonably coordinated, so that the transient recovery voltage rise rate and The rate of current rise while the solid-state DC circuit breaker is conducting is also limited to a reasonable level

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