Earthing Transformers
Neutral Earthing transformers
Earth-transforming generally exists in a three-phase system without neutral and earth fault protection. Neutral earthing transformers are often provided with a Zigzag (interstar) winding which is used in neutral earthing transformers to obtain the needed zero phase impedance. To address the need for an auxiliary power source, an additional auxiliary winding might be offered using the traditional pressed steel radiators, ONAN/ONAF cooling. The range is according to the needs of the location and includes up to 33 KV systems.
A transformer designed specifically for earthing includes zigzag or "interconnected star" winding connections, with each output being the vector sum of two phases offset by 120. It can be used to supply 3-phase power as an autotransformer (acting as the primary and secondary without isolated circuits), to create a missing neutral connection from an un-grounded, 3-phase system so that the neutral can be grounded to an earth reference point, to supply non-standard phase-shifted 3-phase power, and to reduce harmonic currents because it can suppress triplet harmonic currents (3rd, 9th, 15th, and so on).
Three primary and six identical secondary windings, which are employed in zigzag winding connections as shown, are frequently seen in nine-winding three-phase transformers. A normal stand-alone transformer with only six windings on three cores can be utilised in zigzag winding connection, much like the traditional three-phase transformer with a delta or wye winding design. This type of transformer is also often referred to as a zigzag bank. The first coil on each zigzag winding core is always linked in the opposite direction to the second coil on the core after it, whether there are six or nine windings. The phases are then linked to the primary coils, and the second coils are all hooked together to generate the neutral. As a result, each phase interacts with the other phases, cancelling the voltages. As a result, the neutral point, which may be connected to ground, would experience very little current.
Three primary and six identical secondary windings, which are employed in zigzag winding connections as shown, are frequently seen in nine-winding three-phase transformers. A normal stand-alone transformer with only six windings on three cores can be utilised in zigzag winding connection, much like the traditional three-phase transformer with a delta or wye winding design. This type of transformer is also often referred to as a zigzag bank. The first coil on each zigzag winding core is always linked in the opposite direction to the second coil on the core after it, whether there are six or nine windings. The phases are then linked to the primary coils, and the second coils are all hooked together to generate the neutral. As a result, each phase interacts with the other phases, cancelling the voltages. As a result, the neutral point, which may be connected to ground, would experience very little current.
Product Range
Power up to 10 MVA -33 kV.
Distribution up to 5 MVA – 33 kV, Furnace up to 5 MVA – 33 kV,
Rectifier up to 10 KA DC – 33 kV, Reactor up to 2 MVA – 33 kV ,
Earthing up to 2 MVA – 33 kV, Converter Duty up to 5 MVA – 33 kV,
Dry (VPI) up to 2 MVA – 11 kV. – with OLTC also.