Spatial Equity Assessment and Bi-Level Optimization of Distribution NetworkEV Charging Infrastructure Access under Source-Grid-Load-Storage Coordination

The source-grid-load-storage (SGLS) framework integrates PV, distribution networks, EV charging, and storage. However, existing approaches neglect spatial equity in capacity allocation, leading to "charging deserts" in low-income communities. This paper introduces Gini coefficient and Theil index to construct spatial equity constraints, proposing a bi-level optimization model evaluated across 10 typical regional categories. The model reduces Gini to 0.28 at 8%-12% additional cost. PV and EV charging distributions are strongly positively coupled. Spatial equity indicators should be embedded into SGLS planning guidelines.