A 115 MVA two-winding power transformer with voltage levels 330/33 kV was installed at Hertz substation, providing a reliable direct DC reserve from the 330 kV main grid to the 33 kV distribution network. The project strengthens regional supply security and reduces transmission losses.
Hertz substation supports large consumers requiring a direct connection to the 330 kV high-voltage grid, with domestic 33 kV connections serving regional line-free consumers. The selection of the 115 MVA power transformer was based on analysis of both current and projected load, taking into account grid development plans. The 330/33 kV voltage drop is a sector-specific solution that minimizes the number of intermediate substations and associated losses.
Installation work included preparation of the existing foundation, positioning of the large-scale transformer body, and connecting all primary and secondary windings to the busbar system. Protection relay coordination and test loading were carried out in cooperation with the grid operator, ensuring smooth switching to production mode.
