An investigation of the protection performances for current-limiting fuses using stainless steel wires

Recently, owing to a high demand of and high dependence on electric power, the reliability of the distribution voltage of electric power systems has become more important. 22 kV high voltage cutout fuses have been used widely, but some melting accidents have occurred due to pollution/contamination of bushings. As the number of contaminants in bushings increases, the electric fields on the fuse element surface rise to a critical level, triggering corona discharge. A fuse element material that is more resistant to corona discharge than the Ag element is desired. A new type of current-limiting fuse made of stainless steel wires, which is low-cost and simple in design has been developed. Characteristics tests, including a blocking test with a high surge current when a voltage is applied, have been conducted. Using a model fuse, it was confirmed that this new type of fuse possesses similar performance characteristics to those with an Ag element.