A Novel Liquid Metal Fault Current Limiter Based on Active Trigger Method

A novel liquid metal fault current limiter (LMFCL) is introduced to enhance the fault responding performance while increasing the rated current-carrying capacity. The proposed limiter utilizes an active trigger method to ignite the arc, achieving a much shorter pre-arcing time than the previous one, namely the self-pinch LMFCL. Firstly, the arcing phenomenon of liquid metal under a continuous current is studied, which results in a restriction of the rated current for a limiter. Then, the structure and working principle of the active triggered LMFCL are presen- ted. Experimental investigations are conducted to learn the whole arcing process. Furthermore, the current limiting performances based on the novel and conventional methods are compared, and the critical conditions of arc ignition under different parameters are studied. In addition, a continuous current-carrying test is implemented on an improved limiter. The results show that the proposed method is able to shorten the fault responding time significantly, while it allows the LMFCL to carry a considerable rated current.