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Abstract

Contents

Introduction

The quality of electrical energy has now become a familiar and clear concept in the field of supplying consumers of electrical energy. The economic damage from the reduction in power quality resulting from the effects of current and voltage unbalance is caused by deterioration of energy performance and reduction in the service life of electrical equipment, a general decrease in the reliability of electrical networks, an increase in active power losses and the consumption of active and reactive power.

Losses and power quality

Energy losses in power supply systems are largely related to power quality, which in turn is an integral part of electromagnetic compatibility.

It is possible to identify the main indicators of the quality of electrical energy, the deterioration of which leads to an increase in electric power losses:

  • steady state voltage deviation;
  • sinusoidal distortion coefficient of the voltage curve;
  • coefficient of the nth harmonic component;
  • stress unbalance coefficients by reverse and zero sequences.

When the voltage distortion coefficient of the voltage is less than 5%, the additional measurement errors are negligibly small. In turn, the neglect of electricity and the constant deterioration of its quality leads to additional losses of electricity and money of energy supplying organizations. This is due to the fact that indicators of the quality of electricity deteriorated by its consumers are not constantly monitored, which leads to an increase in technical losses of electricity.

The high level of electricity losses in distribution networks of power systems is mainly due to the following factors:

  • technical parameters of network elements;
  • non–optimal operation modes;
  • lack of regulatory funds;
  • high unevenness of the graphs of electrical loads; inefficiency of electricity metering systems;
  • an increase in the installed power of non–linear and asymmetrical loads.

Separation of losses into components can be carried out according to different criteria: the nature of losses (fixed, variable), voltage classes, element groups, production units, etc. For the purpose of analyzing and rationing losses, it is advisable to use an integrated structure of energy losses, in which the losses are divided into components based on their physical nature and specificity of methods for determining their quantitative values.

Based on this approach, the actual losses can be divided into four components:

1) technical losses of electricity due to physical processes occurring during the transmission of electricity through electrical networks and expressed in the conversion of a part of electricity into heat in the network elements.

2) power consumption for substations of substations, necessary to ensure the operation of technological equipment of substations and the life of the staff. This expense is recorded by meters installed on transformers of CH substations.

3) electric power losses due to errors in its measurement (electric power metering, metrological losses). These losses are obtained by calculation on the basis of data on the metrological characteristics and modes of operation of instruments used to measure energy (current transformers, voltage transformers and electricity meters themselves).

4) commercial losses caused by the theft of electricity, inconsistency of meter readings for electricity paid by household consumers and other reasons in the field of energy consumption control.

Load losses include losses:

  • in wires of transmission lines;
  • power transformers and autotransformers;
  • current–limiting reactors;
  • barriers of high–frequency communication;
  • current transformers;
  • connecting wires and buses of switchgears of substations.

Conclusion

Currently, the loss of electrical energy is included in the technical losses of the energy supplying organization, although the quality of electrical energy is most often impaired by its consumers.

The electrical energy transmitted through electrical networks consumes part of itself for its movement. Part of the generated electricity is consumed in electrical networks to create electric and magnetic fields and is a necessary technological expense for its transmission. To identify the foci of maximum losses, as well as the necessary measures to reduce them, it is necessary to analyze the structural components of the power losses. Technical losses are currently of the greatest importance, since they are the basis for calculating the planned standards for electric power losses. Depending on the completeness of information on the load of network elements, various methods can be used to calculate electric power losses. The process of calculating electricity losses is quite time-consuming. To facilitate such calculations, there are various programs that have a simple and convenient interface and allow you to make the necessary calculations much faster.

References

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