Integration of DC circuit breaker and fault current limiter based on zero‐voltage resonant switching approach

Abstract

It is known that most of the renewable energy resources are the DC type. However, DC microgrids do not have zero crossing in current and voltage. This results in serious concerns about the circuit breaking and fault current limiting in the power system. Conventional thyristor-based DC fault current limiters (FCLs) may provide possible solutions for this problem. Unfortunately, a permanent interruption would arise on the system in case of a temporary fault. For this reason, this proposal aims to develop an integration system of the circuit breaker and FCL using a feedback-controlled zero-voltage switching method. In this proposed model, a load current is detected and an appropriate switch signal is thus generated by the controller based on the feedback-control strategy. Once the load current is beyond the predefined value, the switch will be opened to reduce the current immediately for a period of time set by the timer in advance. Then, the switch will be closed again to raise the current continuously until the overload threshold is reached. The switching transition duration is located at the resonant zero voltage, so that no switching power is required. Both simulation and practical performance results confirm that an expected constant load current can be well controlled over an expected range.

HVDC Circuit Breakers: A Comprehensive Review

“…An artificial current zero crossing DC CB based on superconducting fault current limiter without the need for an external charging device is pretended in [165]. Due to the fact that conventional thyristor-based DC fault current limiters are not capable of interrupting a permanent fault, in [166], the integration of DC CB and the fault current limiter based on zero-voltage resonant switching technique is investigated.…”

Achievement of Automatic Copper Wire Elongation System

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