Modernization and Reconstruction of the 220 kV Yuksak Substation (Tashkent)

Our design institute successfully completed the development of the comprehensive design and cost-estimation documentation for the Detailed Design stage within the large-scale program ‘Modernization and Reconstruction of Main Grid Substations’ (Phase I). Construction and installation works have also been completed, and the facility has been successfully commissioned.

Project Client: JSC National Electric Networks of Uzbekistan (Tashkent Main Electric Networks Branch).

Project Description and Significance

The 220/110/35/10/6 kV Yuksak Substation is located in the Yakkasaray District of Tashkent. It is one of the key elements of the capital’s power infrastructure and is intended for the reception, transformation, and distribution of electrical energy, ensuring an uninterrupted power supply to Category I and Category II consumers.

The key feature of the upgraded Yuksak Substation is that it is the first highly reliable compact energy facility in Uzbekistan built entirely on the basis of advanced and environmentally safe enclosed-type technologies.

Key Technical and Engineering Solutions:

During the modernization process, the transition was made from outdoor switchgear (OSG) to modern indoor gas-insulated switchgear (GIS) using SF₆ insulation. To achieve this, a complex of new buildings and structures was designed and constructed within the constraints of the existing dense development area:

• • GIS complexes: Separate buildings were constructed for the 220 kV GIS and 110 kV GIS. The 35 kV GIS equipment was installed in the three-story integrated Central Control Building (CCB).
• • Capacity increase: Two autotransformers were replaced with new higher-capacity 250 MVA units (220/110/10 kV), and transformer T-1 was replaced with a new 63 MVA transformer (110/35/6 kV).
• • 6–10 kV switchgear: Two separate buildings housing indoor switchgear (6 kV and 10 kV) of cabinet design were constructed.
• • Relay protection and automation: Network control and protection systems were upgraded to a modern microprocessor-based platform. The Central Control Building incorporates special shielding of walls, floors, and ceilings using metal mesh to protect personnel from electromagnetic radiation.

• • Safety and automation: A three-level Automated Information and Metering System for Commercial and Technical Electricity Accounting (AIIS KUE) was implemented. Safety within the GIS halls is ensured through continuous automatic monitoring of the gas environment (SF₆ leak detection) integrated with the emergency ventilation system.
• • Engineering infrastructure: Semi-underground and above-ground cable ducts, 100 m³ and 200 m³ oil collection reservoirs, and an automatic fire-extinguishing system with a pumping station and two 400 m³ water storage tanks were designed and constructed.

The successful implementation of the Yuksak Substation project confirms the high qualifications of our institute’s engineers in designing modern, high-tech, and compact power facilities in accordance with international reliability and environmental safety standards.

Thermal Power Engineering CA-2026: Central Asian Energy on the Threshold of Major Changes — Exclusive Interview with Hasan Alimov.

A special report was broadcast about the energy facility — the SF₆ gas-insulated switchgear (GIS) of the 220/110/35/10/6 kV Yuksak Substation, which is the first compact substation in Uzbekistan equipped with a comprehensive set of modern technologies.