EV Feeder Capacity & Transformer Stress Simulator
Investigate the engineering bottleneck that remains after widespread EV adoption: localized distribution substation and service transformer overloads caused by coincident evening Level 2 charging spikes.
1. The Last-Mile Paradox
A country's high-voltage bulk transmission grid can often accommodate national EV power averages. The real bottleneck is the low-voltage distribution network: localized pole-top transformers and street-level feeder cables that were sized in the 1970s for 2–3 kW per house, not multiple concurrent 7.2 kW or 11 kW EV chargers.
2. Coincidence Factor Surge
In traditional grid planning, a diversity factor assumes neighbors do not run all stoves or dryers at the same second. But when commuters arrive home at 6 PM, unmanaged EV chargers turn on simultaneously, skyrocketing coincidence factors from 0.2 to over 0.75 and causing massive voltage sags.
3. Multi-Unit & Curbside Inequity
While suburban owners with single-family garages charge overnight at off-peak rates, multi-family apartment dwellers without dedicated parking rely on public DC fast chargers (50–350 kW). These introduce extreme multi-megawatt spikes on commercial urban substations without predictable overnight smoothing.