  The renewable energy proliferation calls upon the grid operators and planners
to systematically evaluate the potential impacts of distributed energy
resources (DERs). Considering the significant differences between various
inverter-based resources (IBRs), especially the different capabilities between
grid-forming inverters and grid-following inverters, it is crucial to develop
an efficient and effective assessment procedure besides available co-simulation
framework with high computation burdens. This paper presents a streamlined
graph-based topology assessment for the integrated power system transmission
and distribution networks. Graph analyses were performed based on the
integrated graph of modified miniWECC grid model and IEEE 8500-node test feeder
model, high performance computing platform with 40 nodes and total 2400 CPUs
has been utilized to process this integrated graph, which has 100,000+ nodes
and 10,000+ IBRs. The node ranking results not only verified the applicability
of the proposed method, but also revealed the potential of distributed grid
forming (GFM) and grid following (GFL) inverters interacting with the
centralized power plants.
