A Static Voltage Stability Index Evaluation Method Considering Distribution Network Resilience

With the high penetration of renewable energy, distribution networks are evolving into multi-source interconnected networks, posing significant challenges to static voltage stability and resilience. To mitigate instability risks from inappropriate distributed generation (DG) placement and sizing, this paper presents a resilience-aware static voltage stability evaluation method using the Lu-index. Selected for its excellent linearity and real-time performance, this index overcomes the limitations of traditional indices in dynamic scenarios and high R/X ratio networks. Numerical simulations on the IEEE 33-node system quantify the impacts of DG placement, capacity, power factor, and load growth. Results reveal a non-monotonic "U-shaped" voltage stability trend with increasing DG capacity and demonstrate superior stability for mid-feeder DG integration compared to feeder head or feeder end placement. Reverse power flow under light-load conditions is identified as a key terminal integration instability risk. These findings provide theoretical and quantitative support for the scientific planning of DGs in modern distribution networks.