A Novel Busbar Protection for LCC-VSC Hybrid MTDC Transmission System Based on Wavelet Packet Energy

The busbar is a crucial component of hybrid multiterminal direct current (MTDC) transmission systems, playing a vital role in energy collection and distribution. Any fault that occurs in the busbar can severely impact the system's stability. This article examines the magnitude–frequency traits of transient fault currents identified at the busbar, constructs a new start-up criterion for busbar protection based on high-order difference, develops a fault identification criterion based on wavelet packet energy, and proposes a novel busbar protection method. A hybrid MTDC system is established on real-time digital simulator (RTDS). Multiple experimental findings demonstrate the efficacy of the proposed safeguarding technique in accurately detecting busbar faults, tolerates high transition resistance, exhibits strong antiinterference ability, and possesses excellent sensitivity and reliability.