Design and Parameter Characteristics of a New Fault Current Limiter Based on Self-driving Rheostat

Installing fault current limiters (FCLs) can effectively and expeditiously limit the short-circuit fault current, and ensure the reliable interruption of the vacuum circuit breakers (VCBs). However, the current FCLs exhibit certain drawbacks, such as intricate design, reliance on detection apparatus, and high expenditure. Thus, this paper proposes a new FCL based on self-driving rheostat (SD-FCL). In the event of a short-circuit fault, it can leverage the short-circuit energy to confine the fault current, devoid of any current sensing equipment or auxiliary machinery. The study investigates the impact of structural parameters and material properties of the device on magnetic flux density and current density. Various widths, heights, and conductivity parameters are examined using finite element simulation to determine their interaction with magnetic flux density and current density. A prototype is developed, and the parameters are experimentally verified under optimal characteristics. The findings demonstrate that the SD-FCL successfully limits the first peak fault current of 15.5 kA to 13.3 kA at 4.2 ms. The SD-FCL serves as references for the VCB breaking and engineering applications.