As a contractor, Eltel Networks was tasked with expanding and modernizing the 400/220 kV Krajnik substation and converting the 400 kV and 220 kV line sections that entered the premises of the station. The project was highly demanding, both technically and organizationally, as is best demonstrated by several dozen temporary station configurations, which were necessary to carry out our task without interrupting energy transmission.
Jarosław Błażyński
Project Director
Eltel Networks Energetyka SA
FACTS
Investor: Polskie Sieci Elektroenergetyczne SA
Location: Krajnik and Nowe Czarnowo, Gryfino Municipality (Gryfino poviat, Zachodniopomorskie Voivodship)
Investment cost: PLN 185 million
Completion: 2014 - 2021
SUBSTATION DETAILS
- modernization of 400 kV 3/2W switchgear bays – 9 branches
- modernization of 220 kV switchgear bays – 23 bays
- two 400 kV cable lines on the premises of R400 kV
- surface area of the substation of approx. 20.2 ha
CHALLENGE
The biggest challenge during the modernization works was the need to maintain the continuous operation of the substation. As an electric power infrastructure node, this station allows power to be output from the Dolna Odra Power Plant and provides the connection to the German electricity system (Vierraden station).
During the expansion and modernization of the Krajnik substation, the entire station equipment was replaced. The new 400 and 220 kV power equipment and the modern technical building from which the entire substation is operated were constructed. The works carried out by Eltel Networks for the investor covered the following:
- performance of formal and legal works together with obtaining transmission easements and the final decision on building permit
- preparation of construction and working designs, and as-built documentation
- preparation of temporary station configurations necessary for the performance of the works
- preparation and implementation of the Public Communication Program
- reconstruction/modernization of 400 kV 3/2W switchgear bays – 9 branches
- reconstruction/modernization of 220 kV switchgear bays – 23 bays
- construction of two 400 kV cable lines on the premises of R400 kV
- construction of the technical building, including systems including internal and external systems
- construction station auxiliaries building, auxiliary building, pumping station building and exciting valves
- modernization of the AT2 autotransformer station
- construction of the sprinkler system at the AT2 station and conversion of the sprinkler system at the AT3 station
- installation of secondary circuits (power system protection, control and monitoring system, automatic transfer switch, synchronization system, power measurement system, auxiliary systems)
- construction of auxiliary switchgear along with the installation of 220 VDC and 48 VDC batteries
- installation of MV cables (30 kV, 15 kV and 6 kV) for supplying auxiliaries, including the installation of MV switchgears and MV/LV transformers
- installation of data communication systems
- installation of technical protection systems for the substation (technical protection system, fire protection system, fixed fire-fighting equipment)
- access roads, internal roads and sidewalks, land levelling, site lighting, cable ducts, site drainage and fencing of the substation
- construction of lightning protection for the substation, including installation of the earth mesh
- line entries for 400 kV and 220 kV lines, including the conversion of the 220 kV line intersection
- commissioning and acceptance tests
- putting the substation into service
EFFECT
The 400/220 kV substation expanded by Eltel Networks is the largest and most important facility of this type in north-west Poland. This substation makes it possible to output power from the Dolna Odra Power Plant. The Krajnik substation also acts as an inter-system station, which means that it allows international exchange of electricity between the Polish and German power systems. The expansion and modernization of the 400/220 kV Krajnik substation has improved the network operation security and reliability of electricity supply in north-west Poland, in particular in the area of the Szczecin agglomeration.
