An Earthing Transformer is a critical component in power systems, ensuring safety and stability by providing a neutral point for grounding.
Key Functions: –
🔹Safety First – During a fault condition, it allows a controlled amount of current to return to the source, preventing excessive damage.
🔹Neutral Point Creation – Essential for ungrounded systems, it offers a return path for unbalanced loads in delta-connected networks.
🔹Fault Current Limitation – Helps regulate fault currents and protect equipment from damage.
🔹Voltage Stability – Maintains steady system operation during transients and fault conditions.
Common Types:-
✅ Zig-Zag Transformer – Provides low impedance to zero-sequence currents while blocking normal phase currents, making it ideal for ground fault detection.
✅ Delta-Wye Transformer – The delta winding helps dissipate unbalanced loads efficiently while the wye connection provides the neutral point.
Key Components: –
⚙️ Core & Windings – Magnetic core with specially arranged windings to manage fault currents effectively.
⚙️ Neutral Grounding Resistor (Optional) – Limits fault current magnitude to protect equipment and improve system stability.
⚙️ Bushings & Terminals – For high-voltage connection and insulation from the tank and surroundings.
Used extensively in substations and industrial networks, earthing transformers play a vital role in system protection and grounding reliability.
In general, we can say that an earthing transformer is used with delta-configured transformers or generators, where no neutral point is available.
It provides a neutral point for grounding, enabling protection systems to detect and clear ground faults, thereby safeguarding the system from fault conditions and stabilizing voltages.