基于HPFC特征电压主动注入的线路三相自适应重合闸方案

The hybrid power flow controller based on cascade H-bridge (HPFC) technology represents a versatile and cost-effective solution for power flow control. This device capitalizes on the strengths of phase-shifting transformers and power electronic devices, offering benefits for power grid optimization, renewable energy transmission, and flexible interconnection of regions. However, in the event of a permanent fault on the line with HPFC, conventional three-phase reclosing can lead to increased secondary short-circuit currents, posing significant risks to the power grid. The operational characteristics of HPFC render passive fault location methods less effective, thereby affecting fault localization accuracy. This paper presents a three-phase adaptive reclosing scheme for the line based on active injection of characteristic voltage by HPFC. By leveraging the unique features of HPFC, the scheme proposes a novel method for generating and injecting characteristic voltage. Considering factors such as current transformer measurements and transition resistance, the scheme introduces a fault nature criterion using staged characteristic voltage injection. This approach enhances the success rate of three-phase reclosing and ensures fault recovery capability. The feasibility of the proposed scheme is validated through a PSCAD/EMTDC simulation model of the line with HPFC.