Measurement and development division

During 2008 the Division of measurement and development was engaged on working duties compliant with the domain of its obligation and activities arising from the current operation in the transmission department.
1. Analyses, systematic arrangement of data, implementation of projects: - review and systemic arrangement of data in relation to events on 400 kV, 220 kV and 110 kV transmission network with observation for wider time period as a background to prepare the annual working plans of measurement;
- analysis and checking of possibility to apply composite polymer insulators in the electricity transmission in the process of transmission line construction from aspect of advantages and disadvantages compared with the conventional types of insulators
- implementation of rehabilitation of earthwire systems projects – construction of an additional earthwire on:
220 kV OHTL no.255 SS Skopje 1 – HPP Vrutok ;
110 kV OHTL no.121/1, 121/2, 121/3 SS Ohrid 2 – SS Resen – SS Bitola 4;
110 kV OHTL no.107/1, 107/2 SS Kicevo – SS Sopotnica – SS Bitola 1;
110 kV OHTL no.106/2 TPP Oslomej – SS Kicevo

2. Activities related to experts supervision over:
reconstruction of 220 kV and 110 kV OHTL crossing over the main road “North surrounding ring of the city of Skopje”.
Activities have been undertaken to: 220 kV OHTL no.255 SS Skopje 1 –HPP Vrutok
110 kV OHTL no.104/103/3 SS Skopje 1 – SS Jegunovce
110 kV OHTL no.125 SS Skopje 1 – Miladinovci 1
110 kV OHTL no.126 SS Skopje 1 – Miladinovci 2
Laboratory tests have been conducted within these activities to materials built in the transmission lines and control tests of pressing with constructor’s press;

3. Test certificate documentation and technical solutions:
- Test certificate documentation has been produced with respect to transmission line towers for which measurement of earthwire in 2008 was done:

400 kV OHTL no. 422 SS Dubrovo – Greek border
400 kV OHTL no. 421 SS Skopje 4 – SS Dubrovo
110 kV OHTL no. 171 SS Kocani – SS Makedonska kamenica
110 kV OHTL no. 116 SS Stip – SS Probistip
110 kV OHTL no. 164 А,B SS Bitola 2 – SS Bitola 3
110 kV OHTL no. 136 А,B SS Bitola 1 – SS Bitola 2
110 kV OHTL no. 120/2 SS Struga – SS Ohrid 1
110 kV OHTL no. 181 SS Bitola 2 – TPP Bitola 3
110kV OHTL no. 151 SS Bitola 2 – TPP Bitola 1
110 kV OHTL no.152 SS Bitola 2 – TPP Bitola 1
110 kV OHTL no. 153 SS Bitola 2 – TPP Bitola 2

- With regard to the locations based on reports of measurement in the earlier years prepared with the actual technical solutions to improving the earthening by additional earthing in the form of discharges, mutual rings on four feet were prepared or probes placed. The choice of the type of additional earthing was made according to the conditions on site and soil composition including the category of access.

145 Technical solutions have been made in total and treated the following transmission lines:
- 400 kV OHTL no. 420/1 SS Skopje 5 – Kosovo B, 110 kV OHTL no. 117/1 SS Kavadarci – SS Dubrovo, 110 kV OHTL no. 108/3 SS Skopje 1 – SS G. Petrov, 110 kV OHTL no. 105/1 SS Veles – SS Ovce Pole, 110 kV OHTL no. 104/103/3 SS Skopje 1 – SS Tetovo, 110 kV OHTL no. 111 HPP Vrutok – HPP Spile, 110 kV OHTL no. 113/1А, 113/1B, 113/2, 114 SS Veles – SS Veles 2 – SS Zgropolci – SS Kavadarci – HPP Tikves, 110kV OHTL no.119/1 SS Skopje 1 – SS Kumanovo, 110 kV OHTL no.122 SS Kavadarci – SS Prilep 1, 110 kV OHTL no.125 SS Skopje 1 – Miladinovci, 110 kV OHTL no.131/1, 131/2, 132/1 SS Stip 1 – SS Stip 2 – SS Bucim – SS Radovis, 110 kV OHTL no.183 SS Ohrid 1 – SS Ohrid 2.

4. Tender Documentation
- Tender documentation on rehabilitation – construction of additional earthing of 145 tower locations was prepared for the above specified transmission lines, under the technical solutions adopted.

The Tender Documentation prepared related to construction of additional earthing to transmission line towers covers all possible combinations of technical solutions from aspect of type of earthings, type of material used, digging in different composition of soils and method of digging, materials for beneficiation of environment where the earthing is placed, different possibilities to access for off-road vehicle and the location where the activities will be performed (easily or with difficult) etc.

5. Promotion and presentations
Within the framework of its activities the Unit organizes presentation of the firm Trefinasa from Spain, a manufacturer from the ITRAC – Belgium group in relation to the new types of conductors with bigger permissible power of the thermal resistant aluminum alloys conductors type, STACIR and TAL which can be applicable in the transmission network (considerations from technical and economic aspect);

The measuring instrument that the Unit uses is microprocessing controlled universal meter of earthing resistance fully automized measuring frequency of SATURN GEO G upgrading with additional device – external current transformer.

According to the legal obligation related to periodical inspection and/or calibration of the metering instrument by means of which resistance measurement is carried out to earthing (Rules on determining the types of metering instruments which require an obligatory testing of the type, inspection, and periods in which periodical inspection of standards and metering instruments is made, an Official Gazette of R. Macedonia no. 19/96). The Division has undertaken activities in conducting the calibration of measuring instrument (and of current transformer which is used within the scope of the measuring instrument) in the Bureau of Metrology, Ministry of Economy.

Transmission lines on which measurements of earthing resistance and visual inspection are made of the visible part of the earthing system are as follows:

400 kV OHTL no. 422 SS Dubrovo – Greek border
400 kV OHTL no. 421 SS Skopje 4 – SS Dubrovo
110 kV OHTL no. 171 SS Kocani – SS Makedonska Kamenica
110 kV OHTL no. 116 SS Stip – SS Probistip
110 kV OHTL no. 164 А,B SS Bitola 2 – SS Bitola 3
110 kV OHTL no. 136 А,B SS Bitola 1 – SS Bitola 2
110 kV OHTL no. 120/2 SS Struga – SS Ohrid 1
110 kV OHTL no. 181 SS Bitola 2 – ТPP Bitola 3
110 kV OHTL no. 151 SS Bitola 2 – ТPP Bitola 1
110 kV OHTL no. 152 SS Bitola 2 – ТPP Bitola 1

In metering the resistance of earthing to tower locations for the specified transmission lines, also the safety height , the distance of conductors from trees and the eventually new constructed facilitieshave been checked.

Metering of safety height to other transmission lines where need is estimated for checking the crossing over of the lines with other infrastructure has also been made.