RUS UKR DonNTU Masters Portal



Molybog Viacheslav

Viacheslav Molybog  

Electrotechnical Faculty

Department of Electrical Systems

Speciality «Electrical Systems and Networks»

Develop recommendations for the calculation and reduction of power losses in electric networks

Scientific adviser: Ph.D. Larina Inna  



Resume Biography


Abstract


Introduction. Aims and objectives
Valuation losses
Structure of losses
Classification of activities reduced in their realization structural components of energy losses
A review of research
References:



Introduction

      Electrical energy is the only type of product, which is transported from places of production to places of consumption, not using other resources. To this end, spent most of the transmitted power, so its loss is inevitable, the challenge is in determining their economic levels.
      Power losses in electrical networks — is an indicator of efficiency of their work, a clear indicator of the state accounting system power, efficiency, power sales of power supply companies. This indicator shows the problems that require urgent solutions in development, reconstruction and technical re-equipment of electrical networks, improvement of methods and means of their operation and management, to improve the accuracy of metering of electricity, the efficiency of collecting money for a customer-supplied electricity, etc.
      The growth of energy losses in electric networks defined action is the objective laws of development of all energy in general. The main ones are: the trend towards concentration of production of electricity in large power plants, the continuous growth of loads of electrical networks associated with the natural growth of consumer loads and lag the growth rate of network bandwidth on the rate of growth of electricity consumption and generating capacity.
      In connection with the development of market relations in the country the significance of the problem of loss of electricity has increased substantially. Development of calculation methods, analysis of energy losses and the choice of cost-based measures to reduce them is more than 30 years. Due to the complexity of calculating the losses and the presence of significant errors in the recent emphasis on developing methods rationing of electricity losses.
      Methodology for determining the standards of losses has not been established yet. Haven't defined even the principles of valuation. Opinions on the approach to rationing are in a wide range — from the desire to have established a solid standard in the form of a percentage loss to control the "normal" losses by continuously held settlement schemes networks using appropriate software. On the received norms of electricity losses are set electricity tariffs. Regulation of tariffs imposed by NERC of Ukraine. The energy-supplying organization must justify the level of electricity losses, which they consider appropriate to include in the tariff and the energy commission - to analyze these studies and to adopt or revise them.

Valuation losses

      Analysis of international experience shows that the growth of electricity losses in networks — is an objective process for countries with economies in crisis and reforming power, a sign of a discrepancy between the purchasing power of consumers and electricity tariffs, the rate of under-investment in network infrastructure and electricity metering systems, lack of full-scale automated information systems for collecting and disseminating data on the productive supply of electricity, the structure of the flow of electricity at voltage steps, the balance of power in electrical networks [3].
      In countries where these factors are location, power losses in electrical networks, tend to be high and tend to increase. Dynamics of the losses in domestic electrical networks over the past 10-12 years shows that our country is in this sense is no exception.
      Cost of losses — is part of the cost of transmission and distribution of electric networks. The greater the loss, the higher these costs and therefore electricity prices for end consumers. It is known that part of the loss is a technological power consumption required to overcome the resistance of the network and delivery to consumers of electricity generated by power plants. This technologically necessary power consumption must be paid by the consumer. He, in essence, is the norm loss.
      Losses due to suboptimal modes of electric networks, electricity metering system errors, deficiencies in energy sales activities are the direct loss of power supply organizations and, of course, must fall.

Structure of losses

      The basis of normative losses are technical losses of electricity in power grids due to the physical processes of transmission and distribution, determined by calculation and including the "variables" and the quasi-permanent loss, as well as a normative power consumption for its own needs substations [2].


Figure 1. Structure of losses

      As of losses should be included:


Figure 2. Structure of losses

Classification of activities reduced in their realization structural components of energy losses



Figure 3.Classification of activities

      All activities can be roughly divided into five groups:
      May be noted that this division is conditional, but it has a right to exist. For the network companies with substantial stakes networks 10-0,38 kV and a large number of subscribers of the categories of "public" and "non-industrial consumers," the greatest effect brings the realization of some activities of group 3, as well as all the activities of groups 4 and 5. For companies with a predominant share of networks of 35 kV and above should be considered the most relevant activities of groups 1 and 2, and partly of 5. For the network of organizations with extensive networks of enclosed high-voltage carrying significant transit of electricity, particular importance is the activity of 1 [2].

Stages of the program

      In any case, the first stage of developing a comprehensive multi-year program to reduce energy losses should begin with a detailed analysis of the full list of events and choose the most effective and acceptable to the specifics of the organization in question.
       The next thing is the need to define the so-called relative effects of the implementation of activities. The fact is that when planning events and calculating the effect of routine forms, the absolute effect in kWh But as almost any (or at least large) network organization implement activities to reduce losses in the previous reporting period, when determining the cumulative effect over the next few years should be considered and the relative effect, and preferably also for each structural component of the actual loss of electricity. This can be done using the formula:

(1)


       where i — the structural component of the energy losses (1 — technical, 2 — or 3 commercial — losses due to allowable errors of meters — see Fig. 1);
       j — the year in which planned to implement measures to reduce energy losses; Weffi is the relative effect of the implementation of measures to reduce losses in the year j relative to the previous year on the i-th structural component of the losses.
      Then the overall relative effect on all three structural components of the loss can be defined as:

(3)


A review of research

      The problem of calculating the losses of electricity excites power already very long. However, currently available are very few books on the subject, unnecessarily, little has changed in fundamental device networks. But it produced quite a number of articles where clarification is made of old data and proposing new solutions to the problems associated with the calculation, valuation and reducing power losses.
      Article Vorotnitskogo VE, Zaslonova SV and Kalinkin MA "Program for calculating technical losses of power and electricity distribution networks in 6 — 10 kV is described in detail a program to calculate the technical losses of electricity RTP 3.1 Its main advantage is the ease of use and convenient for analysis to conclude the final results, which significantly reduces staff time to carry out the calculation.
      Article Vorotnitskogo VE, Zagorski YA.T. and Apryatkina VN "The calculation, regulation and reduction of electricity losses in urban electric networks" devoted to improving the existing methods of calculating energy losses, the valuation losses in the current conditions, as well as new methods of reducing losses.
       One of the recent books published on the subject is the book Zhelezko YS "Simulation, analysis and valuation of energy losses in electrical networks." In her most fully represents the structure of energy losses, methods of analysis of losses and the choice of measures to reduce them. Substantiated methods of valuation losses. Described in detail the software that implements the methods of calculating the losses.
      In the article Alexander Mogilenko "Reduction of power losses. Approach to planning and assessment activities "[1] developed a group of activities to reduce power losses. Activities are ranked according to the degree of efficiency and sustainability.
      Investigation of power loss and ways to reduce actively carried out in countries where they are large. These countries are Ukraine, Russia and practically all the countries of the former Soviet Union. A large number of articles on the subject translated and published in the international electrical engineering journals, published papers for conferences.
      International studies also reduce to refine the data to find new ways to minimize losses and improve existing ones.       As part of the study DonNTU minimize losses are held regularly in the diploma works of students of the university. Having data on existing networks or parts of the networks used for calculations of losses and their analysis. Selected methods to minimize the losses applicable to the particular enterprise, a specific network, carried out economic evaluation of interventions and their effectiveness.


References:

Resume     Biography