Технические науки/5. Энергетика

Vladyslav Kolotylo

National Technical University of Ukraine “KPI”

Faculty of Electric Power Engineering and Automatics

The issue of necessity of modernisation and technical re-equipment of Kyiv generation centre

Introduction. Ukraine faces several important challenges in modernizing the electric grid. The first one is to make the system of electric supply reliable, adaptable, efficient and being able to withstand power outages, maintain high quality electric service, recover from severe weather events, and save energy. Another challenge is to finance electric grid modernization at the time of limited budget for infrastructure development and state utility companies which are more interested in increased consumption rather than efficiency.

As seen from the last decade’s accidents statistics of the world’s Power Association, operating conditions of current electrical equipment of Kyiv generation centre require modernization and technical re-equipment since accidents, which occur as a result of damages, refuses and maintenance errors, can cause considerable economic losses. Therefore, on the basis of the scientific researches considered in, we will deal with the issue of necessity of modernization and technical re-equipment in view of the following possible post-fault conditions of Kyiv generation centre:

· disconnection of one circuit of the 330 kV line in the area of “Trypils’ka” thermal power plant – “Novokyivs’ka” substation;

· disconnection of one main autotransformer of “Novokyivs’ka” substation;

· disconnection of the 110 kV line in the area of “Darnytsia” CHP – CHP-5;

· disconnection of a power generating unit at CHP- 5.

Research materials. The continuous service of overhead power lines, including 330 kV overhead lines, without technical re-equipment rather often lead to accidents. It is important to note that some equipment of the backbone and distribution networks of Kyiv generation centre is exposed to physical depreciation.

The total length of 330 kV overhead lines of the Kyiv circuitry is 223.4 km. Among them there are lines which have been in use

· for more than 30 years (199.6 km);

· for over 40 years and even more (130.6 km);

· and the 330 kV overhead line between “Novokyivs’ka” substation – “Zhovtneva” substation (34.1 km long), which has been in operation for 47 years.

In 2007 the total length of 110 kV lines of Kyiv generation centre, which include the 110kV lines of AEK «Кyivenergo» and JSC «А.E.S. Kyivoblenergo», was 199 and 2,106 km respectively. About 15-20% of the total length must be reconstructed and replaced according to the action plan adopted by the Cabinet of Ministers of Ukraine.

One should not ignore the problem of autotransformers service life. About 45% of transformer equipment has been in use for 25 years and about 30% – for more than 30 years. As a rule, the extension of the useful life of transformer equipment to 30-40 years is possible only when effective control, diagnostics and before-the-fact prevention of defects is done. Therefore, the service life of 45-50 years should be regarded as critical.

Four 330kV autotransformers of Kyiv generation centre installed at the substations of the central power system have been in use for more than 25 years, and two of them (АТ- 2 at "Pivnichna" substation and АТ-1 at "Brovary" substation) have been in operation for more than 30 years, which indicates that they are obsolescent and worn-out.

At present 92.1 % power generating units at thermal power plants of the United Energy System of Ukraine have already used up their design life (100 thousand hours), and 63.8 % power generating units have gone beyond the world’s power practice limits of maximum useful life and physical wear of 170 thousand and 200 thousand hours respectively and, thus, must be updated or replaced [1].

Conclusion. The result of closing Chornobyl nuclear power plant was the central power system of Ukraine suffering from power shortages. Due to the low level of generation at Kyiv CHP-5 and CHP-6, constantly increasing prices for fuel [2] and working rules of the wholesale market of electric energy the performance of Kyiv generation centre has become rather unstable and any disconnections of electric network elements [3] could cause a serious accident. For this reason, putting additional generating power sources into operation and modernisation of considerable part of power asset of Kyiv generation centre seems to be of practical importance, especially taking into account the rapidly increasing demand for electric power in Kyiv and Kyiv region.

References

1. Паливно-енергетичний комплекс України в контексті глобальних енергетичних перетворень./ Під. заг. ред. А.К. Шидловського. – Київ: УЕЗ, 2004. – 468 с.

2. Knos, I.; Landsberg, M ; Valtin, J. (2014). The challenges for fossil fuel power system associated with integration of large scale renewable generation. Pattaya: IEEE. p. 1-8.

3. Zio, E.; Golea L.R. (2011). Analyzing the topological, electrical and reliability characteristics of a power transmission system for identifying its critical elements. Paris: Reliability Engineering & System Safety. p. 68-74.