As electric vehicle (EV) adoption accelerates, charging stations are becoming essential infrastructure. Transformers serve as the backbone of these systems, converting high-voltage grid power into safe, low-voltage electricity suitable for EV charging.

The Role of Transformers in EV Charging Stations

1. Voltage Conversion

Grid electricity is typically transmitted at high voltages (e.g., 10kV, 35kV), while EV charging piles require much lower voltages (220V or 380V). Transformers efficiently convert this electricity through electromagnetic induction to deliver the appropriate voltage level for charging operations.

2. Electrical Isolation

The insulated design of transformers provides electrical isolation between the grid and charging equipment, preventing faults or interference from damaging EVs or charging infrastructure.

3. Power Distribution and Load Regulation

Transformers in charging stations adapt output power based on fluctuating load demands across different charging piles and time periods, balancing load distribution and avoiding overloads to enhance energy efficiency and stability.

Common Transformer Types in Charging Stations

Dry-Type Transformers

Advantages:

Oil-free design ensures fire and environmental safety

Low maintenance and quiet operation

Suitable for indoor and environmentally sensitive locations

Disadvantages:

Weaker heat dissipation compared to oil-immersed types

Larger size and higher cost

Ideal for: Indoor charging stations in malls, offices, residential garages, and locations with strict environmental and noise requirements.

Oil-Immersed Transformers

Advantages:

Superior cooling and overload capacity

Smaller footprint and lower cost for high-capacity needs

Disadvantages:

Risk of oil leakage and fire hazards

Requires regular oil maintenance

Higher noise levels

Ideal for: Outdoor, high-demand locations such as highways, logistics hubs, and service areas.

Application Scenarios for Transformers in Charging Stations

Urban Public Charging Stations

Located in commercial zones and transportation hubs, these stations require compact, low-noise, and safe transformers to handle peak loads in limited spaces. Dry-type transformers are preferred due to their fireproof and low-maintenance design.

Highway Service Area Charging Stations

These stations handle high power loads during peak travel periods. Oil-immersed transformers are ideal thanks to their excellent cooling and large-capacity performance, suited for fast-charging demands in harsh environments.

Residential Charging Stations

These stations require low-noise, reliable, and safe power for nighttime charging without disturbing residents. Dry-type transformers are most suitable due to their quiet, eco-friendly operation.

Dedicated Charging Stations (e.g., Logistics or Bus Depots)

With consistent high-power requirements, large-capacity oil-immersed transformers are used for centralized charging of fleet vehicles. These systems prioritize reliability and efficiency in managing multiple fast-charging piles simultaneously.

Conclusion: Choosing the Right Transformer for Charging Infrastructure

Transformers are critical components in the successful operation of EV charging stations. From voltage conversion and power distribution to safety assurance and system efficiency, their role cannot be overstated. When building or upgrading charging stations, it is essential to choose the right type and size of transformer based on specific site and operational needs.

As the industry advances, the use of smart, compact, and environmentally friendly transformers will become a major trend, improving the efficiency and safety of EV infrastructure and supporting the global shift toward clean energy transportation.

Related to our products: Explore our range of charging station transformers