The coincidence factor (CF) in EV charging, defined as the ratio of simultaneous charging power to total installed charging capacity, is influenced by driving patterns primarily through their effect on plug-in behavior and temporal distribution of charging events, though studies indicate this influence is less significant than other factors. Here’s the breakdown:
Driving Pattern Impacts
- Plug-in timing: Driving patterns determine when EVs return home or reach charging points, affecting the clustering of charging starts. However, the CF decreases substantially (to <25% for >50 EVs at 11 kW) as fleet size grows, suggesting random arrivals from varied driving schedules help offset synchronization.
- Daily mileage: While driving distances influence energy demand, battery size variations (which correlate with driving needs) have a minor effect on CF compared to fleet size and charging power.
- Activity-based charging: Charging coinciding with workplace, hotel, or home arrivals increases local CF, but the aggregate CF across large fleets remains low due to geographical dispersion and heterogeneous schedules.
Dominant Factors Overriding Driving Patterns
- Fleet size: CF declines nonlinearly with increasing EV numbers, stabilizing below 25% for >50 EVs.
- Charging power: Higher-rated chargers (e.g., 11 kW vs. 3.7 kW) increase per-vehicle demand but reduce simultaneity due to shorter charging durations.
- Ambient temperature: Cold temperatures increase charging frequency and duration, raising CF.
Key Findings from Studies
- Home charging: Synchronized plug-in times (e.g., midnight) create sharper peaks, but CF remains manageable for large fleets.
- Workplace/hotel charging: Higher CF occurs due to clustered arrivals, but absolute values stay low at scale.
- Monte Carlo modeling: Driving and plug-in behaviors contribute less to CF variance than fleet size and charger ratings.
In summary, driving patterns affect CF by shaping plug-in timing and location preferences, but their influence diminishes as EV adoption scales, making fleet size and charging infrastructure design the primary levers for managing grid impacts.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-driving-patterns-affect-the-coincidence-factor-in-ev-charging/
