1. Multi-Tap and Multi-Voltage HV Systems: Flexible Grid Adaptation

Modern transmission and distribution networks often require a single substation node to interface with varying regional overhead line voltages or adapt to ongoing grid modernizations. MAKITEL addresses this complexity by engineering transformers equipped with specialized off-circuit or on-load tap changers linked to multiple primary taps.

Dual/Multi-Voltage Flexibility: These systems are designed with split or multi-tap high-voltage (HV) windings that allow the transformer to switch between different high-voltage levels (e.g., shifting between 10 kV, 20 kV, or 35 kV systems). This ensures that a single unit can be seamlessly redeployed or adjusted as the surrounding grid infrastructure evolves.

2. Stabilizing Windings: Open and Closed Delta Configurations

In transformers where both the primary and secondary windings are connected in a star configuration with an accessible neutral point (Yn-Yn), grid operators face challenges related to triplen harmonics and unbalanced loads. MAKITEL engineers integrate a third (tertiary) stabilizing winding into the core design, operating in two modes:
Closed Delta (Δ): This auxiliary winding provides a closed path for third-harmonic (3rd harmonic) currents to circulate freely.

This eliminates harmonic distortion within the magnetic flux, ensuring a clean sinusoidal voltage wave and drastically reducing supplementary core losses. It also acts as a balancer during severe phase-to-phase load unbalances.

Open Delta (for Protection): This configuration is utilized to connect voltage-monitoring and relay protection equipment. Under normal, balanced grid conditions, the sum of the three phase voltages in the open delta is zero. However, when a phase-to-ground fault (earth fault) occurs in the grid, the symmetry is disrupted. A residual voltage (zero-sequence component) appears across the open terminals, instantly triggering the relay protection to isolate the fault.

3. Rectifier Solutions for Heavy Industry (Multi-Phase Systems)

Industrial plants, metallurgical operations (such as furnace transformers, which are part of MAKITEL’s specialized product lineup), and high-power DC systems require clean power with minimal harmonic distortion. The company builds rectifier transformers featuring specific vector groups:
12-Pulse Rectifier Transformers: These units feature a single primary winding and two independent secondary windings wound on the same core leg. One secondary winding is connected in Star (Y), while the other is connected in Delta (Δ).

Harmonic Cancellation via Phase Shifting: The inherent difference between the Y and Δ connections introduces a natural 30° phase shift between the two secondary voltages. When these two systems are connected to bridge rectifiers, the highly disruptive 5th and 7th harmonics cancel each other out on the primary side. For more advanced 24-pulse or 48-pulse industrial systems, MAKITEL implements additional Zig-zag (Z) windings to achieve ultra-precise, custom phase-shifting angles.

4. Specialized Transformers for Battery Energy Storage Systems (BESS)

The rapid expansion of renewable energy sources and large-scale battery storage units for grid stabilization has driven demand for split-winding transformers. MAKITEL provides cutting-edge solutions featuring multiple independent windings on the low-voltage (LV) side:
Multi-Secondary Construction: A single transformer tank houses two, three, or four isolated LV windings wrapped around the same core leg. Each winding connects to a dedicated inverter from the battery storage array (BESS) or a localized solar PV field.

Galvanic and Magnetic Isolation: The windings are structurally and axially separated inside the tank. This strict decoupling prevents the formation of circulating (loop) currents between parallel-operating inverters. Furthermore, the high short-circuit impedance between the individual secondaries ensures that if a fault occurs in one battery block, it remains isolated, preventing a total system shutdown.

5. Multi-Purpose Transformers with Varying Secondary Capacities
For modern Smart Grids, where a single substation node must simultaneously manage diverse consumers and producers (prosumers), MAKITEL custom-projects transformers with windings featuring entirely different nominal capacities (Sn=Sn1+Sn2+,,,+Sn(n)) and different secondary voltage levels.