UNITED INSTITUTE OF TECHNOLOGY, PRAYAGRAJ
ELECTIC VEHICLE (MNEV401)
UNIT-5 (Battery Charging Infrastructure)
Introduction to Battery Charging Infrastructure
Battery charging infrastructure forms the backbone of the electric vehicle (EV) ecosystem. It
enables EV users to conveniently recharge their vehicles, thereby encouraging the shift from
internal combustion engine (ICE) vehicles to environmentally friendly alternatives. With the
increasing adoption of EVs in both public and private sectors, the development of a robust,
reliable, and accessible charging network is critical. This infrastructure includes various
types of chargers, power electronics, grid connections, and user interfaces to manage the
charging process efficiently.
Types of Charging Stations
Charging stations are generally categorized based on charging speed, power level, and
location:
• AC Charging Stations (Level 1 & Level 2): These stations use alternating current to
charge the EV. Level 1 (up to 3.3 kW) is typically used for home charging with a
standard socket. Level 2 (up to 22 kW) is used in residential complexes and public
parking.
• DC Fast Charging (Level 3): These stations offer high-speed charging (typically 50
kW to 150 kW and beyond), directly supplying DC power to the EV’s battery. They
are suitable for highways and commercial charging hubs.
• Ultra-Fast and HPC (High Power Charging): These are high-end stations (up to 350
kW or more), capable of charging an EV in under 30 minutes. They are increasingly
used for long-range EVs and commercial fleets.
• Battery Swapping Stations: Instead of charging, the depleted battery is swapped with
a fully charged one. It is ideal for two-wheelers, three-wheelers, and fleets for quick
turnaround.
Selection and Sizing of Charging Stations
The selection and sizing of a charging station depend on several factors:
• Type of EVs served (two-wheelers, cars, buses, commercial fleets).
• Charging demand, which includes expected number of users, daily energy
consumption, and peak hour loads.
• Power availability and grid capacity in the area.
• Charging time expectations (slow, moderate, or fast).
• Future scalability and integration with renewable energy sources.
The sizing includes deciding the number of charging points, total installed capacity
(kW or MW), and required transformer or backup power system. Accurate load
forecasting and demand profiling are essential for ensuring optimal utilization and
avoiding over-sizing.
Components of a Charging Station
A typical EV charging station consists of the following main components:
• Electric Vehicle Supply Equipment (EVSE): Includes the charger hardware and user
interface (display, RFID/payment system).
• Power Distribution Panel: Manages electricity distribution, circuit protection, and
metering.
• Charging Controller: Controls the charging process, monitors the battery state, and
ensures safety protocols.
• Communication Modules: For integration with mobile apps, billing systems, and
remote monitoring (using OCPP protocols).
• Transformers & Switchgear: Step down utility voltage and protect against electrical
faults.
• Energy Meter and Billing Unit: Tracks energy usage for each user.
• Auxiliary Power Supply: Powers lighting, cooling, and internal systems of the
charging station.
• Cooling Systems (optional): For high-power DC stations to prevent overheating.
Modern stations may also integrate solar panels, battery energy storage systems
(BESS), and vehicle-to-grid (V2G) technology.
Single Line Diagram (SLD) of a Charging Station
A Single Line Diagram (SLD) is a simplified schematic that represents the electrical layout
of a charging station. Key elements typically shown in the SLD include:
• Incoming Power Line from the utility grid or solar/BESS source.
• Transformer to step down high-voltage supply to EV charging voltage (e.g., 415V
AC).
• Main Distribution Board with circuit breakers.
• Individual Charger Connections branching out from the panel.
• Monitoring, metering, and control units.
• Protective relays and surge protection devices.
SLDs are critical for electrical engineers during installation, maintenance, and
troubleshooting.
Charging Station Placement for Electric Vehicles
Strategic placement of charging stations ensures accessibility, minimal range anxiety, and
grid balance. Factors influencing placement include:
• Traffic density and user demand: Stations should be located in high-demand areas
like highways, malls, offices, and residential complexes.
• Proximity to power sources and substations: Reduces installation cost and
transmission losses.
• Land availability and ease of access: Preferably roadside or parking-lot based.
• Integration with public transport: Especially important for e-buses and fleet-based
mobility solutions.
• Safety and security: Stations must be well-lit, monitored, and safe for 24x7 operation.
• Scalability: Future expansion should be considered, including space for additional
chargers or battery swapping units.
Urban planners and DISCOMs (Distribution Companies) often collaborate to ensure optimal
placement aligned with urban mobility plans and smart grid development.
Case Study: EV Charging Infrastructure in Delhi, India
Delhi has emerged as a leading city in India for EV adoption, backed by proactive
government policies under the Delhi EV Policy 2020. The Delhi government, in partnership
with DISCOMs and private players, has successfully initiated the installation and
commissioning of public charging stations across the city.
• Objective: To install 500+ public charging stations and over 100 battery swapping
points.
• Approach: Used the single-window clearance system, reduced license fees, and
subsidized installation costs for private stakeholders.
• Components: Charging points are equipped with fast and slow chargers, integrated
billing systems, and real-time app-based status updates.
• Placement: Strategically placed at metro stations, parking lots, public buildings, and
petrol stations.
• Outcomes: Enabled faster EV adoption (especially two and three-wheelers), reduced
air pollution, and demonstrated a replicable model for other Indian cities.
The Delhi model highlights the importance of policy, planning, and public-private
partnerships in accelerating EV infrastructure.
