Zero-point earthing transformers serve as a critical mechanism in power systems engineering to generate an artificial neutral reference within ungrounded or delta-connected networks. From an analytical perspective, isolated medium-voltage networks suffer from severe phase-voltage displacement and dangerous transient overvoltages during single line-to-ground faults. By introducing a low-impedance path for zero-sequence currents, these specialized units stabilize healthy phase potentials. They also facilitate precise fault-current detection for protective relaying schemes.

Zero Point transformers

Makitel has mastered the precise physics governing these phenomena, engineering ultra-reliable grounding systems that satisfy the most stringent international grid standards.
The optimal design paradigm relies on a zigzag (Zn) winding configuration, which possesses unique electromagnetic properties. Under symmetrical, steady-state grid conditions, the interconnected windings on each core limb generate counteracting magnetomotive forces. This yields an exceptionally high positive-sequence impedance and negligible excitation currents.

However, during an asymmetrical earth fault, the zero-sequence currents flow co-directionally through the split windings. This induces a highly effective magnetic flux cancellation that results in an extremely low zero-sequence impedance. Consequently, the transformer safely channels severe thermal and electrodynamic stresses without exceeding magnetic saturation limits.

Makitel's advanced technological framework addresses these rigorous engineering demands through superior production methodologies at their state-of-the-art facility near Ohrid. Our team designs and manufactures highly sophisticated zero-point earthing transformers engineered to provide artificial neutral points for ungrounded networks while integrating multiple sub-systems into a single, compact solution. To optimize substation footprint and efficiency, Makitel offers these units with or without an auxiliary transformer built-in, providing reliable low-voltage power supply for nearby villages and local utilities.

To ensure complete monitoring and protection, the design can feature integrated Current Transformers (CT) and Potential Transformers (PT) directly embedded within the system. Furthermore, Makitel utilizes specialized open and closed delta stabilization windings to effectively suppress third-harmonic voltages and balance zero-sequence impedances during transient faults. For ultimate grid protection, these grounding units can be manufactured with or without an adjustable Petersen coil (Arc Suppression Coil) integrated inside the very same tank, creating a fully unified, cost-effective, and high-performance grid protection hub.