Z-Type Grounding Transformer
Product Introduction
This transformer adopts a Z-type, or zigzag, winding connection. Unlike a conventional transformer, each phase winding is divided into two sections and wound in opposite directions on different core limbs.
This connection allows zero-sequence magnetic flux to circulate through the core limbs. In a conventional transformer, zero-sequence flux mainly flows through the leakage magnetic circuit.
As a result, the zero-sequence impedance of a Z-type grounding transformer is very low, generally around 10 Ω, while the zero-sequence impedance of an ordinary transformer is much higher.
According to the relevant requirements, when a conventional transformer is used together with an arc-suppression coil, the capacity of the arc-suppression coil should not exceed 20% of the transformer capacity.
A Z-type grounding transformer can support an arc-suppression coil with a capacity equal to approximately 90% to 100% of the transformer capacity.
In addition to connecting an arc-suppression coil, the grounding transformer can also supply a secondary load. It can therefore replace a station service transformer and help reduce project investment costs.
