With more power electronics deployed in power system, the propagation of cascading failure become more complex and it is necessary to investigate the mechanism of cascading failure in the novel power system. This paper reveals a new cascading failure mode in multi-infeed high voltage direct current (HVDC) systems. Firstly, the mechanism of multi-timescale cascading failure is proposed. Then the simulation results of multi-infeed HVDC systems which is carried out in Power system department-Bonneville power administration (PSD-BPA) indicate that the dominant cascading failure modes in different timescales are different and they are coupling with each other. Finally, several dominant factors of different timescale cascading failure modes are pointed out.

multi-timescale cascading failure;cascading commutation failure;cascading outages of lines;multi-infeed HVDC systems