Multi-Objective Optimization Framework for Equitable Charging Infrastructure Deployment
Urban electric vehicle (EV) infrastructure faces a critical "last mile" problem: charging stations cluster in affluent city centers while peripheral residential districts become "charging deserts." In Berlin, this spatial inequality leaves 45% of residents with inadequate access to charging infrastructure.
Districts like Mitte benefit from over-supply (18 BEVs per charging point), while Treptow-Köpenick faces severe congestion ratios exceeding 32:1—nearly double the sustainable threshold of 28 BEVs per point.
This technical brief presents a validated geospatial optimization methodology that achieves a 13.2% reduction in spatial inequality while maintaining network profitability. The framework combines NSGA-II genetic algorithms with fuzzy-robust logic to solve for optimal placement of 500 new charging stations across Berlin's 11 administrative districts.
The Non-dominated Sorting Genetic Algorithm II (NSGA-II) is a multi-objective evolutionary optimizer that explores thousands of deployment configurations to identify the Pareto optimal front—the set of solutions where no objective can be improved without degrading another.
Objective 1 (Maximize Utility):
f₁(x) = Σ (Pᵢ × Cᵢ) / Σ Pᵢ
Where Pᵢ is population density and Cᵢ is charging coverage
in district i.
Objective 2 (Minimize Inequality):
f₂(x) = (1 / 2n²μ) × ΣΣ |rᵢ - rⱼ|
Where rᵢ is the BEV-to-charger ratio in district i (Gini
coefficient).
To account for uncertainty in EV adoption forecasts, we employ fuzzy logic control that accommodates demand variations up to ±20%. This ensures the infrastructure remains effective even if adoption accelerates or stalls relative to projections.
The model integrates multiple geospatial layers:
| District | Chargers | BEVs | Ratio | Status |
|---|---|---|---|---|
| Mitte | 495 | 8,900 | 18.0 | ✓ Healthy |
| Friedrichshain-Kr. | 370 | 7,500 | 20.3 | ✓ Healthy |
| Pankow | 345 | 10,500 | 30.4 | ✗ Critical |
| Treptow-Köpenick | 172 | 5,500 | 32.0 | ✗ Critical |
Full district data available in the complete IEEE paper. Critical threshold: 28 BEVs per point.
The equity-centric strategy prioritizes peripheral districts (Pankow, Treptow-Köpenick, Marzahn-Hellersdorf) to achieve maximum fairness gain with minimal profitability trade-off.
Run parallel simulations with different governance priorities:
All charging infrastructure must comply with VDE-AR-N 4110 technical connection rules for low-voltage networks in Germany.
| Parameter | VDE Requirement | Model Constraint |
|---|---|---|
| Power Factor | ≥ 0.95 @ full load | Enforced |
| Voltage Deviation | ± 10% (Un) | Monitored |
| Harmonic Distortion | THDi < 8% | Grid impact analyzed |
| Load Management | Dynamic curtailment capable | Required for all stations |
Current model operates at district level. Next iteration will refine to 100m × 100m grid cells for street-level precision.
Incorporate bidirectional energy flow constraints to optimize grid stability during peak demand.
Add household income layers to further refine equity metrics and subsidize installations in low-income areas.
This technical brief summarizes the peer-reviewed methodology published in the 2025 IEEE International Conference on Emerging Trends in Engineering and Computing (ETECOM).
DOI: 10.1109/ETECOM66111.2025.11318989
Citation: C. O. Ondieki and T. Lu, "Enabling Equitable EV Charger Deployment in Berlin with
Multi-Objective Geospatial Optimization," 2025 IEEE ETECOM, Best Paper Award (Intelligent Transportation
Track).