Mathematical model of the short circuiting process in the electrical power network with the current-limiting device based on liquid metal self-healing fuse

The paper claims that fast response and current-limiting properties of the liquid metal self-healing fuse are of  interest  regarding their using in power supply systems. However, the level of researches, both in our country and abroad, does not allow us to proceed with the development of production prototypes of liquid metal self-healing fuse. Further research is necessary.

To investigate the short-circuiting process in the alternating current mains, a mathematical model is proposed, which, compared to the known one, allows to investigate the current-limiting properties of liquid metal self-healing fuse more carefully  for removing short-circuiting current, alike a current-limiting reactor. The model includes resistance of the electric arc during the switching process. The period of arcing can be divided into infinitesimal sections, the arc resistance at each one is assumed to be linear.

The results of the calculation are presented in the form of oscillograph records. The analysis of calculated oscillograph records allows us to state that the nature of current changes in the electric circuit with the liquid metal self-healing fuse is in full accordance with the main provisions of electric circuit theory, and the mathematical model adequately shows a clear picture of the short-circuiting process.

The comparison of calculation results with the oscillogram  received from the experiment shows their complete identity, which confirms the adequacy of the proposed mathematical model to physical processes in the short circuit with the liquid metal self-healing fuse. It is recommended to use the model to determine the requirements for protection device parameters based on the liquid metal self-healing fuse during their development, design and operation.