A novel cascaded full-bridge high voltage DC circuit breaker and its control method

Abstract

The invention provides a novel cascaded full-bridge high-voltage direct current circuit breaker and its control method, which include a main flow branch, a transfer current branch and an energy absorption branch connected in parallel; the main flow branch and the transfer current The full-bridge module in the branch circuit includes the first resistor, the first capacitor, the first switch and four fully-controlled power electronic devices; the four fully-controlled power electronic devices and the first capacitor form a power module with a full-bridge structure, and the first A resistor is connected in series with the first switch and then connected in parallel with the first capacitor. Compared with the prior art, the present invention provides a novel cascaded full-bridge high-voltage DC circuit breaker and its control method, through which the first switch can quickly discharge the first capacitor through the first resistor, and after the discharge of the first capacitor is completed, It can quickly restore the blocking state, so that the capacitor voltage of each low-voltage capacitor is zero when the high-voltage DC circuit breaker is reclosed, and will not discharge the fully-controlled power electronic devices and damage the high-voltage DC circuit breaker.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a novel cascaded full-bridge high-voltage direct current circuit breaker and a control method thereof. Background technique [0002] The hybrid high-voltage DC circuit breaker composed of mechanical switches and fully-controlled power electronic devices can effectively break the DC of the multi-terminal flexible DC grid due to its low loss characteristics of mechanical switches and fast breaking characteristics of power electronic devices. . However, the breaking capacity of the current hybrid DC circuit breaker is limited by the breaking capacity of a single power electronic device, and its breaking current is less than 10kA, which is difficult to meet the actual breaking current demand of the flexible branch circuit breaking system. At the same time, it is difficult for the hybrid DC circuit breaker to quickly release the capacitor voltage inside the power electronic...

AI Technical Summary

Problems solved by technology

However, the breaking capacity of the current hybrid DC circuit breaker is limited by the breaking capacity of a single power electronic device, and its breaking current is less than 10kA, which is difficult to meet the actual breaking current demand of the flexible branch circuit breaking system

At the same time, it is difficult for the hybrid DC circuit breaker to quickly release the capacitor voltage inside the power electronic device unit after the breaking is completed, resulting in damage due to DC short circuit during rapid reclosing

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