Metaheuristic Algorithms for Optimal Design of VSC-HVDC Fault Current Limiters

Off-shore wind energy worldwide is considered an under-utilized renewable energy source (RES). One of the major hurdles in this regard is the utilization of modern transmission line technologies. The voltage source converter (VSC) based high voltage direct current (HVDC) is the most trusted option to stimulate the maximum off-shore wind energy. The VSC-HVDC technology has several advantages and limitations. The network of VSC-HVDC lines can be exposed to massive short circuit faults, which can result in substantial losses for the converter station. Conventional hybrid DC circuit breakers (HCBs), to some level, can handle fault current, yet with the increased capacity of VSC-HVDC lines, these breakers also suffer because of power handling issues. Breakers are typically used with fault current limiters (FCLs) to overcome capacity-related challenges. For applying FCLs to enhance the performance of the DCCBs, the sizing of the current limiting components remains an essential factor. The increased size of these components can result in increased inertia of the breaker, reduced overall system efficiency, and increased cost. This paper explores the possibilities of using metaheuristic techniques to optimize the values for FCLs. In this regard, one FCL based HCB is taken as an example; its mathematical model is analyzed, and objective functions are developed to optimize the component size. Performance analysis is conducted in PSCAD/EMTDC and MATLAB-based simulations and programming. The significance of the genetic algorithm is established to optimize the size of current limiting components in FCL based HCBs.