Dry-type + Isolation + Three-Phase: Why This Transformer Has Become the Standard for New Energy Charging Stations

In the field of electric vehicle charging infrastructure, the transformer is a critical component that converts high grid voltage into the lower voltage required to charge batteries. With the rapid rise of EV adoption, demand for charging stations has increased dramatically. A closer look at large-scale public fast-charging stations shows that they are almost always equipped with dry-type isolation three-phase transformers. This is not a coincidence but the result of their outstanding performance in safety, efficiency, and reliability.

Core Characteristics of Dry-Type, Isolation, and Three-Phase Transformers

Dry-type transformer: Unlike oil-immersed transformers, dry-type units use epoxy resin insulation. They eliminate oil leakage risks, offer high fire resistance, are environmentally friendly, and require minimal maintenance.

Isolation transformer: Provides electrical separation between the grid and the charging station, preventing direct interference from surges and voltage spikes. This ensures safe and stable charging operations.

Three-phase transformer: A high-efficiency power solution capable of delivering large-scale energy, meeting the needs of modern DC fast charging (DCFC). It surpasses single-phase power systems in stability and efficiency.

Why the Combination is Standard in EV Charging Stations

1. Ultimate Safety

Isolation transformers block grid-side surges and noise, reducing electric shock risks. Dry-type transformers eliminate flammable oil, preventing fire or explosion hazards. This allows installation in indoor spaces, underground parking garages, or next to charging piles, reducing site restrictions and costs.

2. High-Power Fast Charging Support

With EV fast charging evolving from 60kW to 240kW and beyond, three-phase transformers efficiently handle high-power output with reduced line losses. They balance loads across phases, enhance power quality, and ensure stable performance even during peak charging hours.

3. Environmental Adaptability and Low Maintenance

Dry-type epoxy-cast transformers resist humidity, corrosion, and salt spray, making them suitable for coastal or harsh environments. They are virtually maintenance-free, reducing operational costs and supporting unmanned charging stations. The absence of oil prevents soil or water contamination, aligning with green energy standards.

4. Improved Power Quality

By suppressing harmonics and electromagnetic interference, isolation transformers create a stable power environment. This protects sensitive electronic components such as IGBTs in charging piles, reducing failure rates and extending service life.

In modern EV charging stations, where safety, efficiency, reliability, and environmental sustainability are critical, the dry-type isolation three-phase transformer has become the proven industry standard. Its ability to ensure safe operations, deliver high-power output, adapt to harsh environments, and maintain power quality makes it the optimal choice for the future of new energy infrastructure.