Increasing NPS reliability degree by upgrading Iernut 400/220/110 kV substation

Short description:

Iernut 400/220/110 kV substation is an important power node of NPS, in Transylvania zone, ensuring the power transfer from power excessive areas to the Northern Transylvania zone of power shortage and the discharge of power from Iernut TPP, respectively.

The project object refers to the connecting operation of the TPP Iernut 100 MW units, G1 and G2, to 220 kV voltage, G3 and G4 to 110 kV voltage respectively, to the upgraded 400/220/110 kV Iernut substation.
G5 and G6 -200 MW units connecting to the substation (220 kV voltage) represented the object of a different design contract, concluded by ISPE, in the year 2006 for the same end-user.

The existing TG unit transformers T201 and T202, afferent to G1 and G2 units respectively, were connected to the substation 220 kV bay, using one general connecting circuit, partially cable-inlet and partially overhead performed. These connecting circuits were equipped with:

single-phase, 220 kV, XLPE-insulated cable and outdoor, dry-type sealing ends.
220 kV switchgear, measuring transformers, surge arresters, re-used from the own, existing bays.
aluminum-steel flexible conductors, supported to the new metallic frames (beams and pillars) by rod-type double insulator strings, of composite materials.

Each existing TG transformer T103 and T104, afferent to the units G3 and G4 respectively, was connected to its own 110 kV bay, through one 110 kV connecting circuit, partially overhead and partially cable-inlet performed, equipped with:

single-phase, 110 kV, XLPE-insulated cable and outdoor, dry-type sealing ends.
110 kV switchgear, measuring transformers, surge arresters, re-used from the own, existing bays.
aluminum-steel flexible conductors, supported by rod-type double insulator strings, of composite materials.

For the power supply of Iernut TPP auxiliary services, there were provided new, 6 kV cable-inlet connections between the upgraded 110 kV substation and the existing 6 kV substation of the power plant.

Supplied services:

Detail design for: 220 kV and 110 kV primary circuits, 6 kV and 1 kV cable networks, civil works, outdoor electrical lighting installations, land arrangements and roads;
Technical assistance.

Estimated technical performances:

By the upgrading operation of Iernut 400/220/110 kV substation, the bays afferent to Iernut TPP units were provided with state-of-the art equipment, placed in a new site which demanded the performance of new connecting circuits for discharging the TPP-generated power.

The use of combined connecting solutions, overhead and cable-inlet connecting circuits, allowed the connections performance all over the limited existing area, simultaneously with the upgrading works for the power discharge substation and with the re-use of the existing high voltage equipment, in compliance with the end-user request.

Estimated economic efficiency:

TPP generated power supply, with the specified and regulated quality indicators and parameters, for the power system, under reliability and continuity conditions.
Having in view the future upgrading operation of the existing units, using modern combined-cycle generating units, the power supplied for the system will be generated at higher rates, reducing the environmental negative impact to the regulated standards.

Country and location:

Romania, Iernut locality, Mures district

Client:

Energomontaj SA – IEA Bucharest Subsidiary

Start / Completion date (commissioning):

02.2007 – 06.2007

enlarge image

ISPE