110 kV and 220 kV bays overhaul and upgrading – 220/110/20/6 kV FAI substation

The 220/110 kV FAI substation is an important power node, having in view its multiple functions, such as the power injection ensurance from the zonal power transmission grid to the power distribution grid of Iasi city, ensuring the power distribution to the consumers of power, discharged from the transmission system and from local power supplies and representing, along with the 220/110 kV Munteni substation, the only power supplies for the geographical area between Iasi, Birlad and Pascani.

The 110 kV and 220 kV substations rehabilitation operation consists of capital repair works and upgrading works, aiming to bring this connection and transformer substation to an appropriate technical level, in terms of the substation power importance.

The works, pertaining to the substation upgrading, are related to the new 110 kV and 220 kV bays or to those with a new location, due to the upgrading operation.

The rehabilitation works will be performed by stages, using the “step by step” method, maintaining the actual constructive arrangement, simultaneously with the upgrading works for the control – supervisory-protection system.

Assuming the importance of 220/110 kV FAI substation for NPS, the end-user requested the ensurance of a raised degree of reliability in supplying the power consumers of the zone, throughout the performance of the rehabilitation works.

The Project provided, in this respect, the following:

• provisional works in the primary and secondary circuits of the 110 kV substation
• provisional works on 110 kV OHLS
• by the Project-adopted works staging program, the reducing to minimum of the number and duration of decommissioning operations for the existing circuits and the feature of making redundant some power supply ways.

The Project is meant to achieve a new, outdoor-type substation, provided with modern, reliable and performing equipment, including all arrangements and auxiliary installations.

The new 220/110 kV substation will be outdoor-type, air-insulated and it will be performed, at both voltages, with a double bus-bar system, under a flexible variant.

In the 110 kV substation, the circuit-breakers will be arranged on 2 rows, each side of the bus-bar spans and in the 220 kV substation, the circuit-breakers will be arranged on one row. The overhead, flexible connections will be made of aluminum-steel, flexible conductors, supported to frames by double insulator strings, of composite material.

The primary equipment location was established in such a way that it shall allow the access to equipment, requiring more frequent maintenance works, in compliance with the electrical insulation and protection clearances, according to the norm requirements and without de-energizing some parts of the substation. In this respect, the existing roads, under-crossing the 110 kV bus-bar system 1, will be dismantled and it will be built up two new road segments, within the CR works, between the circuit-breakers row and that of the current transformers, placed each side of the bus-bar spans.

There were also built new road segments for accessing the voltage transformers and surge arresters, installed on the 110 kV and 220 kV lines, as well as on the storage platform.

The connection of the existing 200 MVA-220/110 kV auto-transformers of the substation to the pertaining 110 kV bays, was performed via:

• one cable-inlet connection, with single-phase, 110 kV, XLPE-insulated cable and provided with outdoor, dry-type sealing ends, for AT1
• one overhead connection, made of flexible conductors supported by centrifuged reinforced concrete frames, for AT2.

Supplied services:

• basic design and tender documents for civil and mounting works performance, for 220 kV and 110 kV primary circuits, 1 kV cable network, civil works, outdoor electrical lighting and sewage installations, land arrangements and roads
• detail design
• technical assistance.

Estimated technical performances:

• bringing the 220/110 kV FAI substation to a technical level appropriate to the zone and the project energy importance, using the worlds state-of-the art technique
• ensurance of a increased degree of safety and reliability in supplying the zonal power consumers throughout the period of upgrading works performance and the equipment lifetime as well.

Estimated economic efficiency:

• ensurance of power transfer and supply for the power system, with the specified and regulated indicators and parameters and under safety and continuity conditions
• reducing of maintenance costs.

Country and location:

Romania, Iasi city, Iasi district

Client:

Energomontaj SA – IEA Bucharest Subsidiary

Start / Completion date (commissioning):

09.08.2007 – under progress