The application of superconducting Fault Current Limiters in Manitoba Hydro HVDC system

As a result of the development of a third Bipole and additional generation in Manitoba Hydro NCS system, many of the existing station breaker ratings are exceeded. In addition, the ac faults at a single station affect all three Bipoles due to tight coupling between converter stations, which results in a large HVdc power loss. The application of a superconducting Fault Current Limiter (SFCL) in this multi-bipole HVdc system is introduced. The preliminary locations and parameters of the SFCLs were determined based on station short circuit levels and HVdc system responses. The PSS/E and PSCAD/EMTDC studies reveal that SFCLs applied in the single integrated HVdc collector system could effectively reduce the fault currents and also effectively mitigate the influence of a converter station fault on the rest of the converter stations. The impact of the SFCL´s recovery time as an important parameter on system performance is discussed in the paper.