What is the earthing transformer?

Earthing transformers are often used to provide an artificial loadable neutral point for the systems without a neutral point. The neutral point can be directly grounded, or it can be grounded through an electrical reactor, a resistor or an arc suppression coil; the earthing transformer can also be fixed additionally with a continuously running secondary winding (low-voltage winding) as the power supply for the substation.

Earthing transformers serve a crucial function in electrical systems by connecting the neutral point to the earth. This connection is pivotal for several reasons:

Electrical Safety

System Stability

Fault Detection

The Advantages of Earthing Transformers

Earthing transformers of advantages that contribute to the overall safety and reliability of electrical power systems:

• Low zero-sequence impedance
• Low loss level, low noise
• Long service life
• High magnetizing impedance

The earthing transformer creates a neutral point for a network. ZN connection is usually applied. Z connection provides linear and specified zero sequence impedance. YN+d can also be applied.

Earthing transformersTechnical Specification：

Conclusion

oil immersed earthing transformer (neutral coupler) is a three-phase transformer connected to the power system to provide a neutral connection for earthing, either directly or via impedance. The earthing transformers may, in addition, supply a local auxiliary load.