Abstract
Content
- Introduction
- 1. The relevance of energy saving in the energy sector of Ukraine
- 2. Measures to reduce the consumption of electricity in power grids
- 3. Methods for calculating the components of the technical losses of electricity
- References
Introduction
The government at the EU-Ukraine summit, which took place in February 2013, reported that "the results and plans for the future implementation of complex political, social and economic reforms aimed at achieving European standards in all areas without exception". Separately, the summit discussed the topic for reducing energy consumption and increasing the share of renewable energy sources. For Ukraine, the issue is as relevant as ever.
Transmission and distribution of electricity in power grids is necessarily accompanied by loss of power. Reduction of energy losses is one of the main issues electricity.
The purpose of the master's work is the analysis of existing measures to reduce the power losses in electric networks and the development of a mathematical model of energy losses in the regression analysis.
1. The relevance of energy saving in the energy sector of Ukraine
Ukraine belongs to energy deficient states meet their fuel and energy needs through its own production by less than 50% [1]. Due to the constant increase in the world price for carbon energy policy of the government of Ukraine is aimed at reducing energy use, purchased abroad at the expense of foreign exchange earnings. Therefore, due to this reduction, a significant proportion of the energy industry to ensure vested in the energy industry.
Energy indicators, electricity consumption Electricity Consumption (TWh) and electricity consumption per capita Electricity Consumption / Population (kWh / capita) are seeing an increase in electricity consumption in Ukraine and in the countries with developed economies. Consumption and production of electricity in 2010 in some countries are shown in Fig. 1 (compiled from [2]).
Figure 1 – Consumption and production of electricity
(animation: 11 frames, 5 cycles of repetition, 124 kbps)
According to the analysis of power consumption in Ukraine since 1990. to 2008. can be divided into two major periods: from 1990. by 2001, from 2001 to 2008, where, in 1990 – the year of the highest electricity consumption, which is taken as the base, in 2001 – the year of the lowest power consumption.
In the period from 1990 to 2001, there is a tendency to reduce the annual energy consumption compared to the previous year. Electricity consumption for the period decreased from 227.2 billion kW · h in 1990 to 122.5 billion kW · h in 2001, ie by 104.7 billion kW · h, or by 46.1%.
In the period from 2001 to 2008, the positive trend of annual increase of electricity consumption compared to the previous year except for the last financial year (2008), which recorded a slight decrease in power consumption – by 0.4%. Increase in power for 8 years named was 25.4 billion kWh · h or 20.7% [3].
The last few years have seen a trend towards the resumption of intensive development of major regional centers of Ukraine such as Kiev, Donetsk, Kharkov, Dnepropetrovsk. So, Kiev is not only achieved in 2008, the level of power consumption baseline year of 1990, but also exceeded it by 17.9%. In a significant investment restrictions energy conservation is the most rational way of energy supply as a social production and private consumption.
At the same time, the electric power industry is characterized by the crisis of the technical equipment. The degree of wear and tear in the power of the country exceeds 50%. Therefore the question of the introduction of energy-saving technologies is extremely relevant. Due to the high level of wear and tear increases the level of energy losses. Energy conservation can be a source of additional funds for the installed power industry.
Energy is the subject of research in real time. The problems of energy conservation in Russia and Ukraine are involved in such scholars as E.P.Ostrovsky, M.V. Samoilov, Y. Zhelezko, S.M. Safyants other.
2. Measures to reduce the consumption of electricity in power grids
Transmission and distribution of electricity in power grids is necessarily accompanied by loss of power. Actual losses in electricity (ALE) contain two components:
- technological power losses (ТPL);
- commercial losses of electricity (CLE).
Technological losses of electricity, in turn, are divided into optimal technological losses (under optimal network) actual loss of power – additional process losses – at a deviation from the optimal mode. Furthermore, there is the proportion technological losses caused power quality parameters and deviations of quality from their normal values [4]. Such a classification shows that the proportion of power losses is not necessary and their decline is economically feasible.
Quantitative analysis of power losses made in the presentation of them depending on the main influencing factors. These include [5]:
- loading EPT;
- exchange power flow;
- the degree of compensation of reactive power flows;
- the degree of approximation to the optimal mode;
- the level of automation of the network mode;
- level-load losses of electrical equipment.
Reduction of energy losses by means of appropriate measures. Measures to reduce the cost of technology in electrical networks, depending on the volume of capital investments are divided into organizational and technical. Technical activities related to capital investments, organizational – virtually none.
The organizational measures are:
- Optimization places opening lines of 6-35 kV with two-way power..
- Optimization of management modes of the main electrical supply, transformation coefficients and reactive power.
- Shifting generators of power in the synchronous compensator.
- Alignment of load electricity consumers.
- Optimization of load distribution between the main power grid substations of 110 kV and above its switching scheme.
- Optimization places open circuit electrical networks with different nominal voltages.
- Optimization of operating voltages in the power centers of radial electric networks.
The technical measures include:
- Installation and putting into operation of devices for reactive power compensation in electrical networks energy entities.
- Replacing the wires on the congested lines.
- Replacing branches from 0.38 kV overhead line to the buildings.
- Replacement of the power transformers.
- Installation and commissioning of new power transformers at existing substations.
- Replacing the underused power transformers.
- nstallation and commissioning work on transformers with load tap changer devices for automatic control of the transformation ratio.
- Installation and putting into operation of devices for automatic power control of capacitor banks.
- Automation of management modes of electrical networks.
- Shifting of electrical networks on higher rated voltage.
- Promote the establishment and administration of the work of compensating devices in consumers consuming more than 5000 kvar · h.
- Installation for the fore-aft adjustment of power flow in heterogeneous closed electric networks [6].
3. Methods for calculating the components of the technical losses of electricity
Depending on the completeness of the information about the load power supply and the type of measures to reduce energy losses to determine the load losses of electricity is recommended to use the following methods:
- element by element calculations;
- characteristic modes;
- typical day;
- modeling of the factor loadings;
- dominant harmonics;
- medium loads;
- the maximum number of hours of power losses;
- depending on the regression.
For different types of electrical networks we recommend the following methods of calculation.
The method of element analysis is recommended primarily for individual lines and transformers (especially with the use of telemetry), the loss of electricity which essentially depend on the transit flows.
The method of characteristic modes is recommended for the calculation of energy losses in the transit network with an electric telecommunication data about the loads of nodes periodically to the subject of energy.
Method typical day is recommended as the best for the calculation of losses in closed electric networks of 110 kV and above, which do not participate in the exchange of power. Permitted to use the method of maximum number of hours of power losses.
Modeling method of factor loadings, the dominant harmonics are recommended as the best for long-term calculations in any electrical networks with characteristic energy losses. The accuracy of calculations increases with the use of telemetry. Effectively combined application of these methods.
Method medium loads recommended as the best for open-loop power grids 6 - 150 kV in the presence of data on electricity, which is transmitted through the main portion of the grid for the period. Allowed the use of the maximum number of hours of power losses. Statistical methods are recommended to determine the losses in electric networks 0,38 kV and detection of power losses based on the main factors affecting in networks of all voltage classes.
For the calculation of the estimated losses in open-loop power grids 0.38 - 6 - 20 kV is allowed as an exception to the use of regression methods for the determination of equivalent resistance lines from the generalized scheme parameters (total length and number of line segments, crossing the main plot, etc.).
As indicated above, opened electric circuits 6 - 150 kV medium loads recommended method. Determination of load power losses ΔW н in megawatt-hours methods medium loads and maximum number of hours of power losses τ performed by the formulas:
where ΔРL.mean і ΔРL.маx – load power loss determined from the average and maximum loads, respectively, MW;
Кf – shape factor graph, r.u.;
Т – the duration of the period for which are determined by the loss of electricity, h.
Average load of nodes is determined by the meter readings of electricity. Value Кf2 and τ directly determine the total load on the schedule grid, which is fixed in the dispatch particulars, or formulas:
where Кfil – filling factor graph, r.u.;
Тмаx – utilization hours of maximum load.
For electrical circuits with the likes of load power loss calculation can be performed on two stationary modes, one of which corresponds to the expected value, and the other – the dispersion of these graphs [6].
This master's work is not completed yet. Final completion: December 2013. The full text of the work and materials on the topic can be obtained from the author or his head after this date.
References
- Півняк Г. «Енергозбереження в промисловому секторі економіки». Энергосбережение № 8, 2007.
- Key World Energy STATISTICS 2012 [Электронный ресурс]. – Режим доступа: http://www.iea.org....
- Чернышев В.М., Плачинда В.Д., Комарова В.А. Анализ динамики потребления электрической энергии в Украине за период с 1990 г. по 2008 г. и структуры потребления электрической энергии //Электрические сети и системы. - 2009. - № 6. С 6-10.
- Воротницкий М.Э., Железко Ю.С., Казанцев В.Н. и др., под ред. В.Н. Казанцева. Потери электроэнергии в электрических сетях энергосистем – М.: Энергоатомиздат, 1983. – 368 с.
- Амельницкая Е.В. Совершенствование управления локальными электрическими сетями как субъектами хозяйствования // Наукові праці Донецького національного технічного університету. – Донецьк, ДонНТУ, 2005. – с.101-115.
- Методичні вказівки з аналізу технологічних витрат електроенергії та вибору їх зниження. – Київ, ОЕП "ГРІФРЕ", 2004. – 159 с.
- Компенсация реактивной мощности у потребителей [Электронный ресурс]. – Режим доступа: http://www.energosovet.ru....
- Державних будівельних нормах України. ДБН В.2.5-23:2010. [Электронный ресурс]. – Режим доступа: http://dbn.at.ua....