Rehabilitation of the dispatching transmission system of Transelectrica
Short description:
During 2000-2002, ISPE, as a general designer, performed the technical-economic documentation for the fibre optical telecommunications network of the National Power System. The total length of the telecommunications network is 3600 km.
At present, ISPE Bucharest is working-out the last stage of TRANSELECTRICA telecommunications network design (900 km) so that at the end, the National Power Dispatcher and the main locations in the territory should be interconnected (territorial dispatchers, transformation substations, hydroelectric power plants, etc). The design includes the interconnection between the NPS and the Hungarian power system. The solution adopted for carrying out the telecommunications network, according to the provisions of the European Commission, by rehabilitating the NPS with modern telecommunication systems is able to provide the same services as the other public operators. Thus, the 220 and 400 kV lines were used as support for installing optical fibre ground wire (OPGW).
The aim of the new telecommunications network is to ensure the transmission of data, voices and images for the following systems and functions:
- The EMS/SCADA, Metering and MIS/GIS systems;
- The control of the electric transmission system loading frequencies;
- The active and reactive voltage control;
- Supervising and control of the substations and protective diagrams;
- Metering the power transmitted to the interior and trans-boundary;
- Intercommunicating with the similar power systems entities in neighbouring countries;
- Providing the National Power Dispatcher with all input/output data necessary for the power system operation;
- Providing all the data necessary for the other technical and economic operation entities in the system. The optical fibre telecommunications network provided the opportunity of performing OHTL rehabilitation works:
- Replacing the protection steel conductors under an advanced state of corrosion;
- Replacing the porcelain rod insulation;
- Replacing the insulation in areas hard to be accessed with composite insulation.
Supplied services:
ISPE as the engineering company performed:
- Feasibility Study.
- Basic end Detail Engineering.
- Bid Documents.
- Approval and authorizations documentation.
- Documentation of getting out of the agricultural and forest circuit of the land necessary to perform the works.
Main technical characteristics:
Basically, the link between the two substations of the system has been done overhead through OPGW conductor instead of the OPUG (optical fibre underground cable) between the OHTL end towers and the control rooms in the end substations.
At the special line segments other types of optical fibre conductors were used, namely:
in the case of the OHTL without a conductor due to special weather conditions all dielectric self supporting (ADSS) cable was used, mounted on wooden or concrete towers on the OHTL neighbouring lines;
in the case of the great crossings (the River Danube) the optical attached cable (OPAC) cable was used, mounted on the existing protection conductor.
Performances:
The optical fibre type used was single-mode (non-zero dispersion shifted single mode) and the number of optical fibres in a cable was 36 or 72 optical fibres protected in a stainless steel or aluminium tube. This type of fibre allows conveying digital optical flows at initial capacities of 2.5 Gbps, in dense ware length division multiplexing technology (DWDM), on distances reaching 145 km.
The use of optical fibre telecommunications system has the following advantages:
Optical fibres are characterized by a very low damping of the signal (< 0.25 dB/km), which allows long transmission distances;
The special transmission capacity of the optical fibres ensures high transfer speeds (2.56 Gbps) and a high number of data.
Country/ location:
Romania /Location: the entire territory of Romania
Client:
CN TRANSELECTRICA SA (National Company for Electricity Transmission Systems)
Start date commissioning:
2000 - 2004
Associated companies:
FICHTNER ROMELECTRO ENGINEERING; ISCE; TRAPEC;RADIOPROIECT
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