Opportunities to reduce losses in electrical networks. The structure of electricity losses in electrical networks. Technical power losses What types of power losses exist

Introduction

Literature review

1.2 Load power losses

1.3 No-load losses

1.4 Climate losses of electricity

2. Methods for calculating electricity losses

2.1 Methods for calculating electricity losses for various networks

2.2 Methods for calculating electricity losses in distribution networks 0.38-6-10 kV

3. Programs for calculating electricity losses in distribution networks

3.1 The need to calculate the technical losses of electricity

3.2 Application of software for calculating electricity losses in distribution networks 0.38 - 6 - 10 kV

4. Regulation of electricity losses

4.1 The concept of the loss standard. Methods for setting standards in practice

4.2 Loss specifications

4.3 The procedure for calculating the standards for electricity losses in distribution networks 0.38 - 6 - 10 kV

5. An example of calculating electricity losses in distribution networks 10 kV

Conclusion

Bibliography

Introduction

Electrical energy is the only type of product that does not use other resources to move it from the places of production to the places of consumption. For this, part of the transmitted electricity itself is consumed, so its losses are inevitable, the task is to determine their economically justified level. Reducing electricity losses in electrical networks to this level is one of the important areas of energy saving.

During the entire period from 1991 to 2003, the total losses in the energy systems of Russia grew both in absolute terms and as a percentage of electricity supplied to the grid.

The growth of energy losses in electrical networks is determined by the action of quite objective laws in the development of the entire energy sector as a whole. The main ones are: the trend towards the concentration of electricity generation at large power plants; continuous growth of loads of electric networks, associated with a natural increase in loads of consumers and a lag in the growth rate of network throughput from the growth rate of electricity consumption and generating capacities.

In connection with the development of market relations in the country, the importance of the problem of electricity losses has increased significantly. The development of methods for calculating, analyzing power losses and choosing economically feasible measures to reduce them has been carried out at VNIIE for more than 30 years. To calculate all components of electricity losses in the networks of all voltage classes of AO-energos and in the equipment of networks and substations and their regulatory characteristics, a software package has been developed that has a certificate of conformity approved by the CDU of the UES of Russia, the Glavgosenergonadzor of Russia and the Department of Electrical Grids of RAO "UES of Russia".

Due to the complexity of calculating losses and the presence of significant errors, special attention has recently been paid to the development of methods for normalizing power losses.

The methodology for determining loss standards has not yet been established. Even the principles of rationing have not been defined. Opinions on the approach to rationing range widely - from the desire to have an established fixed standard in the form of a percentage of losses to control over "normal" losses with the help of ongoing calculations according to network diagrams using appropriate software.

According to the received norms of electricity losses, tariffs for electricity are set. Tariff regulation is entrusted to the state regulatory bodies FEK and REC (federal and regional energy commissions). Energy supply organizations must justify the level of electricity losses that they consider appropriate to include in the tariff, and energy commissions should analyze these justifications and accept or correct them.

This paper considers the problem of calculation, analysis and regulation of electricity losses from modern positions; the theoretical provisions of the calculations are presented, a description of the software that implements these provisions is given, and the experience of practical calculations is presented.

Literature review

The problem of calculating electricity losses has been worrying power engineers for a very long time. In this regard, very few books on this topic are currently being published, because little has changed in the fundamental structure of networks. But at the same time, a fairly large number of articles are published where old data are clarified and new solutions are proposed for problems related to the calculation, regulation and reduction of electricity losses.

One of the latest books published on this topic is Zhelezko Yu.S. "Calculation, analysis and regulation of electricity losses in electrical networks" . It most fully presents the structure of electricity losses, loss analysis methods and the choice of measures to reduce them. The methods of normalization of losses are substantiated. The software that implements the loss calculation methods is described in detail.

Earlier, the same author published the book "Selection of Measures to Reduce Electricity Losses in Electric Networks: A Guide for Practical Calculations". Here, the greatest attention was paid to methods for calculating electricity losses in various networks and the use of one or another method depending on the type of network, as well as measures to reduce electricity losses, was justified.

In the book Budzko I.A. and Levina M.S. "Power supply of agricultural enterprises and settlements" the authors examined in detail the problems of power supply in general, focusing on distribution networks that feed agricultural enterprises and settlements. The book also provides recommendations on organizing control over electricity consumption and improving accounting systems.

Authors Vorotnitsky V.E., Zhelezko Yu.S. and Kazantsev V.N. in the book "Electricity Losses in Electric Networks of Energy Systems" discussed in detail the general issues related to reducing electricity losses in networks: methods for calculating and predicting losses in networks, analyzing the structure of losses and calculating their technical and economic efficiency, planning losses and measures to reduce them.

In the article by Vorotnitsky V.E., Zaslonov S.V. and Kalinkini M.A. "The program for calculating the technical losses of power and electricity in distribution networks 6 - 10 kV" describes in detail the program for calculating the technical losses of electricity RTP 3.1 Its main advantage is ease of use and easy-to-analyze conclusion of the final results, which significantly reduces personnel labor costs for calculation.

Article Zhelezko Yu.S. "Principles of regulation of electricity losses in electrical networks and calculation software" is devoted to the actual problem of regulation of electricity losses. The author focuses on the purposeful reduction of losses to an economically justified level, which is not ensured by the existing practice of rationing. The article also makes a proposal to use the normative characteristics of losses developed on the basis of detailed circuit calculations of networks of all voltage classes. In this case, the calculation can be made using the software.

The purpose of another article by the same author entitled "Estimation of electricity losses due to instrumental measurement errors" is not to clarify the methodology for determining the errors of specific measuring instruments based on checking their parameters. The author in the article assessed the resulting errors in the system for accounting for the receipt and release of electricity from the network of an energy supply organization, which includes hundreds and thousands of devices. Particular attention is paid to the systematic error, which is now an essential component of the loss structure.

In the article Galanova V.P., Galanova V.V. "Influence of the quality of electricity on the level of its losses in the networks" attention is paid to the actual problem of the quality of electricity, which has a significant impact on the losses of electricity in the networks.

Article by Vorotnitsky V.E., Zagorsky Ya.T. and Apryatkin V.N. "Calculation, regulation and reduction of electricity losses in urban electrical networks" is devoted to clarifying existing methods for calculating electricity losses, normalizing losses in modern conditions, as well as new methods for reducing losses.

The article by A. Ovchinnikov "Electricity losses in distribution networks 0.38 - 6 (10) kV" focuses on obtaining reliable information about the operation parameters of network elements, and above all about the load of power transformers. This information, according to the author, will help to significantly reduce the loss of electricity in networks of 0.38 - 6 - 10 kV.

1. Structure of electricity losses in electrical networks. Technical losses of electricity

1.1 Structure of electricity losses in electrical networks

During the transmission of electrical energy, losses occur in each element of the electrical network. To study the components of losses in various elements of the network and assess the need for a particular measure aimed at reducing losses, an analysis of the structure of electricity losses is performed.

Actual (reported) electricity losses Δ W Rep is defined as the difference between the electricity supplied to the network and the electricity released from the network to consumers. These losses include components of a different nature: losses in network elements that are purely physical in nature, the consumption of electricity for the operation of equipment installed at substations and ensuring the transmission of electricity, errors in recording electricity by metering devices and, finally, theft of electricity, non-payment or incomplete payment meter readings, etc.

Currently, there is an increase in actual (reported) losses of electricity in electric networks. Over 10 years, the total electricity losses in networks of all voltage classes increased from 78 to 107.5 billion kWh (from 10.1 to almost 13%). Technical losses exceed 74%, commercial - respectively - 26%. In some grid companies, the actual power losses exceed 30% with justified technical losses of 5–12%. In networks with a voltage of 220 kV and below, power losses account for 78% of the total losses, of which:

In 110-220 kV networks - 28%,

In 35 kV networks - 16%

In networks 10 - 0.4 kV - 34%.

Electricity losses that do not depend on the load (“conditionally constant”) make up 24.7%, “load losses” (depending on the amount of power transmitted through the network) - 75.3% of the total losses.

As part of the load losses:

86% - losses in power lines,

14% - in transformers.

In semi-permanent losses:

67% - no-load losses of transformers,

11% - losses in own needs of substations,

22% - other losses.

An analysis of the dynamics of absolute and relative losses of electricity in Russian networks, their modes of operation and load shows that there are practically no significant reasons for the growth of technical losses due to the physical processes of transmission and distribution of electricity. The main reason for the losses is the increase in the commercial component.

The main factors behind the growth of technical losses are:

Deterioration of electrical equipment;

Use of obsolete types of electrical equipment;

Non-compliance of the electrical equipment used with the existing loads;

Non-optimal steady-state modes in RSC networks in terms of voltage and reactive power levels;

Influence of the wholesale electricity market on grid modes.

The main factors behind the growth of commercial losses are:

Unacceptable errors in electricity measurements (non-compliance of metering devices with accuracy classes, current transformers with existing loads, violation of verification deadlines and malfunctions of metering devices);

Use of imperfect methods for calculating the amount of electricity supplied in the absence of metering devices;

Imperfection of methods for taking readings from metering devices and issuing receipts directly by subscribers in the domestic sector;

Growth of non-contractual and unaccounted for electricity consumption (theft);

Distortion of volumes of electricity supply to consumers.

The structure of commercial losses of electricity in distribution networks.

Actual losses, i.e. The difference between the electricity supplied to the grid and paid for electricity, in aggregate, has four components:

1) technical losses, due to physical processes occurring during the transmission of electricity through electric networks and expressed in the conversion of part of the electricity into heat in the elements of networks;

2) electricity consumption for own needs of substations and ice melting necessary to ensure the operation of the technological equipment of substations, power lines and the life of the maintenance personnel;

3) electricity losses due to instrumental errors in its measurement(instrumental loss);

4) commercial losses due to theft of electricity, inconsistency of payment for electricity by household consumers with meter readings, delayed payments, non-payment of bills and other reasons in the field of organizing control over energy consumption. Commercial losses do not have an independent mathematical description and, as a result, cannot be calculated autonomously. Their value is determined as the difference between the actual (reported) losses and the sum of the first three components, which are technological losses.

Commercial power losses are a manifestation of the “human factor”. They have organizational, economic, psychological and legal roots. Available statistics show an almost universal increase in electricity losses. In some regions, they have reached 15–20% of the useful supply of electricity, and in municipal city and district electric networks, their share is 25–50%. Losses from commercial losses at the present stage are estimated at about 30 billion rubles a year. Tax arrears to the budgets of all levels exceed 7 billion rubles a year.

An analysis of the dynamics and structure of electricity losses indicates an increase in losses in those energy systems where the share of domestic and small motor loads is significant. If we take into account that commercial losses are concentrated mainly in 0.4–10 kV networks and, for objective reasons, the load on 0.4 kV electrical networks will increase due to the outpacing growth in household electricity consumption, the share of losses in distribution networks in the coming years will also will grow. Undoubtedly, ensuring accurate instrumental accounting of supplied and consumed electricity is an important issue that many experts pay attention to when talking about the need to reduce electricity losses in electrical networks. However, this does not eliminate the problem of commercial losses in general, but only allows energy supply companies to establish more accurate instrumental accounting of electricity supplied to consumers, and due to this, receive additional financial resources from them.

In the general case, the components of commercial electricity losses are proposed to be grouped into three groups:

Caused by measurement errors of electricity supplied to the network and usefully supplied to consumers;

Caused by an underestimation of useful supply due to shortcomings in energy sales activities and theft of electricity;

Caused by arrears in payment for consumed electricity.

In addition to the above components of commercial losses related to the last two groups, we single out four additional components.

1) losses caused by intentional understatement of payments by consumers. The occurrence of such losses is most likely where the meter is located on the territory of the owner - an individual, and access to it for the supervisory personnel of the power supply company is difficult for legal reasons.

2) losses associated with the costs of the energy supply company for the implementation of measures to collect debts and identify the facts of theft of electricity(legal, travel expenses, etc.).

3) losses caused by the actions of dispatching personnel power grid company (wholesale electricity supplier) and related to the introduction of a power consumption limitation regime for an energy supply company (capacity limitation when there is a threat of loss of stability of the energy system due to a shortage of generating capacity or when a large debt arises from an energy supply company to a wholesale electricity supplier).

4)losses due to violation of power quality and the legal refusal of the consumer to fully pay for low-quality electricity or additional costs to the energy supply organization to eliminate the consequences of a violation of the quality of electricity (repair of electrical equipment, taking measures to localize and eliminate the causes of a violation of the quality of electricity, etc.).

The generalized structure of commercial electricity losses in distribution networks is shown in fig. 2.3. (

An urgent issue in the modern electric power industry is the loss of electricity, which is closely intertwined with the financial component. This is a kind of reserve for obtaining additional benefits, increasing the profitability of the production process. We will try to deal with all the facets of this issue and give a clear idea of the intricacies of electricity losses in networks.

What is electrical energy loss?

In a broad sense, electricity losses should be understood as the difference between receipts in the network and actual consumption (useful supply). The calculation of losses involves the determination of two quantities, which is carried out through accounting for electrical energy. Some stand directly at the substation, others at the consumers.

Losses can be calculated in relative and absolute values. In the first case, the calculation is performed as a percentage, in the second - in kilowatt-hours. The structure is divided into two main categories by reason of occurrence. General losses are called actual and are the basis of the efficiency of the unit.

Where is the calculation done?

The calculation of electricity losses in electrical networks is carried out in the following areas:

For enterprises generating energy and giving it to the grid. The level depends on the production technology, the correctness of determining their own needs, the availability of technical and commercial accounting. Generation losses are borne by commercial organizations (included in the cost) or are added to the standards and actual values for districts or electric grid enterprises.
For high voltage network. Long-distance transmission is accompanied by a high level of electricity losses in the lines and power equipment of 220/110/35/10 kV substations. It is calculated by determining the standard, and in more advanced systems through electronic metering devices and automated systems.
Distribution networks, where losses are divided into commercial and technical. It is in this area that it is difficult to predict the level of magnitude due to the complexity factor of tying subscribers with modern accounting systems. Losses in the transmission of electricity are calculated according to the principle received minus the payment for the consumed electrical energy. The definition of the technical and commercial part is carried out through the standard.

Technical losses: physical causes and where they occur

The essence of technical losses lies in the imperfection of technology and conductors used in the modern electric power industry. In the process of generation, transmission and transformation of electricity, physical phenomena arise, which create the conditions for current leakage, heating of conductors or other moments. Technical losses can occur in the following elements:

Transformers. Each power transformer has two or three windings, in the middle of which there is a core. In the process of transforming electricity from more to less, heating occurs in this element, which implies the appearance of losses.
Power lines. When energy is transported over distances, current leaks to the corona for overhead lines, heating the conductors. The following technical parameters affect the calculation of losses in the line: length, cross section, specific density of the conductor (copper or aluminum), power loss factors, in particular, load distribution factor, shape factor of the graph.
Optional equipment. This category should include technical elements that are involved in the generation, transportation, accounting and consumption of electricity. The values for this category are mostly constant or counted through counters.

For each type of electrical network elements for which technical losses are calculated, there is a division into no-load losses and load losses. The former are considered a constant value, the latter depend on the pass level and are determined for the analyzed period, often for a month.

Commercial losses: the main direction of increasing efficiency in the electric power industry

Commercial losses of electricity are considered to be difficult to predict, as they depend on consumers, on their desire to deceive the enterprise or the state. The basis of these problems are:

seasonal component. The presented concept includes the underpayment of individuals for the actually supplied electric energy. For example, in the Republic of Belarus, there are 2 reasons for the appearance of the "season" - this is the availability of tariff benefits and payment not on the 1st, but on the 25th.
Imperfection of metering devices and their incorrect operation. Modern technical means for determining the consumed energy have greatly simplified the task of the subscriber service. But electronics or an improperly adjusted accounting system can fail, which causes an increase in commercial losses.
Theft, underestimation of meter readings by commercial organizations. This is a separate topic for conversation, which involves various tricks of individuals and legal entities to reduce the cost of electricity. All this affects the growth of losses.

Actual losses: total

To calculate the actual losses, it is necessary to add the commercial and technical components. However, the actual calculation of this indicator is carried out differently, the formula for energy losses is as follows:

Loss value = (Receipts to the network - Useful supply - Flows to other energy systems - Own needs) / (Receipts to the network - Lossless - Flows - Own needs) * 100%

Knowing each element, determine the actual loss as a percentage. To calculate the required parameter in absolute terms, only the numerator must be calculated.

Which consumers are considered lossless and what are overflows?

The above formula uses the concept of "lossless", which is determined by commercial meters in high voltage substations. An enterprise or organization independently bears the cost of electricity losses, which are taken into account by the meter at the point of connection to the grid.

As for the flows, they are also lossless, although the statement is not entirely correct. In a general sense, this is electrical energy that is sent from one power system to another. Accounting is also carried out using instruments.

Own needs and losses of electric energy

Own needs must be attributed to a special category and section of actual losses. For the operation of power grids, costs are required to maintain the functioning of substations, cash settlement centers, administrative and functional buildings of RESs. All these values are fixed and reflected in the presented parameter.

Methods for calculating technical losses at electric power enterprises

Losses of electricity in electrical networks are carried out according to two main methods:

Calculation and compilation of the loss standard, which is implemented through special software, which contains information on the topology of the circuit. According to the latter, standard values are determined.
Compilation of unbalances for each element of electrical networks. This method is based on daily, weekly and monthly balance sheets in high voltage and distribution networks.

Each option has its own characteristics and effectiveness. It must be understood that the choice of option also depends on the financial side of the issue.

Loss rate calculation

The calculation of electricity losses in networks in many countries of the CIS and Europe is carried out using this methodology. As noted above, the process involves the use of specialized software, which contains standard values and the topology of the electrical network diagram.

To obtain information about technical losses from an employee of the organization, it will be necessary to enter the characteristics of the active and reactive energy feeder pass, determine the maximum values for active and reactive power.

It should be noted that the error of such models can reach up to 25% only when calculating power losses in the line. The presented method should be treated as a mathematical, approximate value. This is the imperfection of the methodology for calculating technical losses in electrical networks.

Calculation software used

At the moment, there is a huge amount of software that performs the calculation of the standard of technical losses. The choice of this or that product depends on the cost of service, regionality and other important points. In the Republic of Belarus, DWRES is considered the main program.

The software was developed by a group of scientists and programmers of the Belarusian National Technical University under the guidance of Professor Fursanov N.I. The tool for calculating the loss standard is specific, has a number of systemic advantages and disadvantages.

For the Russian market, the RPT 3 software, which was developed by the specialists of JSC NTC Electric Power Industry, is especially popular. The software is quite good, performs the tasks, but also has a number of negative sides. Nevertheless, the calculation of standard values is carried out in full.

Compilation of unbalance in high-voltage and distribution networks

Technical power losses can be identified through another method. It has already been mentioned above - it is assumed that all high-voltage or distribution networks are tied with metering devices. They help to determine the value as accurately as possible. In addition, this technique provides a real fight against non-payers, theft and misuse of power equipment.

It should be noted that such an approach, despite its effectiveness, is not applicable in modern conditions. This requires serious measures with high costs for the implementation of tying all consumers with electronic metering with data transfer (ASKUE).

How to reduce technical losses: methods and solutions

The following areas help to reduce losses in lines, transformer substations:

Correctly chosen mode of operation of the equipment, capacity loading affects the load losses. That is why the dispatcher is obliged to choose and maintain the most acceptable mode of operation. It is important to refer to the presented direction the choice of normal break points, calculations of the load of transformers, and so on.
Replacing equipment with new equipment that has low idle rates or better handles load losses. For power lines, it is planned to replace wires with a larger cross section, use insulated conductors.
Reduced equipment maintenance time, which leads to a reduction in energy consumption for own needs.

Reducing the commercial component of losses: modern opportunities

Electricity losses in the commercial part involve the use of the following methods:

Installation of metering devices and systems with a smaller error. Currently, options with an accuracy class of 0.5 S are considered optimal.
The use of automated information transmission systems, ASKUE, which are designed to remove seasonal fluctuations. Monitoring readings is a condition for combating theft and underreporting.
Implementation of raids on problematic addresses, which are determined through the system of balances of the distribution network. The latter is relevant when tying subscribers with modern accounting.
Application of new technologies to determine the underestimation of systems with current transformers. Specialized devices recognize the coefficient of displacement of the tangent of the distribution vector of electrical energy.

Losses of electricity in electrical networks is an important indicator that has significant potential for commercial organizations in the energy business. Reducing actual losses leads to an increase in profits, and this affects profitability. In conclusion, it should be noted that the optimal level of losses should be 3-5%, depending on the area.

The transmission of electricity through wires in electrical systems is associated with losses of active and reactive power and energy. Losses of electricity associated with its transmission and distribution are made up of two main components - losses of electricity in power lines, generators, transformers and other elements of the electrical system and the so-called commercial (non-technical) losses caused by imperfect systems for accounting and controlling the use of electricity.

Actual (reported) electricity losses is the difference between the electricity supplied to the network and the electricity released from the network to consumers, determined according to the data of the accounting system for the receipt and useful supply of electricity. These losses include components of a different nature: losses in network elements that are purely physical in nature, the consumption of electricity for the operation of equipment installed at substations and ensuring the transmission of electricity, errors in fixing electricity by metering devices and, finally, theft of electricity by influencing meters, non-payment or incomplete payment of meter readings, etc.

Separation of electricity losses can be carried out according to various categories: by the nature of losses (permanent, variable), voltage classes, groups of elements, production units, etc. For the purposes of normalizing losses, it is advisable to use an enlarged structure of electricity losses, in which they are divided into components from their physical nature and the specifics of methods for determining their quantitative values. Based on this approach, the actual losses can be divided into four components:

technical power losses, due to physical processes in wires and electrical equipment that occur during the transmission of electricity through electric networks and are expressed in the conversion of part of the electricity into heat in the network elements. Technical losses cannot be measured. Their values can only be obtained by calculation based on the known laws of electrical engineering;
electricity consumption for own needs of substations required to ensure the operation of the technological equipment of substations and the life of the maintenance personnel, determined by the readings of the meters installed on auxiliary transformers of substations of 35 kV and above;
electricity losses due to instrumental errors in its measurement (instrumental losses) - underestimation of electricity due to the technical (metrological) characteristics and modes of operation of devices used to measure energy at the facility (current and voltage transformers of the electricity meters themselves). These losses are obtained by calculation; the calculation of metrological losses includes all metering devices for electricity supply from the network, including metering devices for electricity consumption for substation own needs;
commercial losses consist of losses due to theft of electricity, inconsistencies in meter readings with payment for electricity and other reasons in the field of organizing control over energy consumption. Commercial losses do not have an independent mathematical description and, therefore, cannot be calculated autonomously. Their value is defined as the difference between the actual (reported) losses and the sum of the first three components.

Note that it is not science that forces us to determine the structure of losses (for scientific research, all approaches make sense), but economics. Therefore, economic criteria should be applied to analyze reported losses. From the point of view of economics, losses are that part of electricity for which the registered useful supply to consumers turned out to be less than the electricity received by the network from electricity producers. The useful supply of electricity is understood not only as the electricity for which the funds actually arrived at the settlement account of the energy supply organization, but also the one for which the invoices were issued, i.e. when the energy consumption is fixed. Billing is a practice applied to legal entities whose energy consumption is recorded on a monthly basis. In contrast, monthly meter readings that record household energy consumption are usually unknown. The useful supply of electricity to household subscribers is determined by the payment received for the month, therefore, all unpaid energy automatically falls into losses.

The energy balance can be represented as follows:

Where wp- electricity supplied to the network; W no- useful electricity supplied to consumers; A.W. TexH- technical losses of electricity; A.W.CM- part of the energy spent for production and own needs of energy systems; 5 W K0M- commercial power losses.

Technical energy losses are usually divided into load and idle losses. No-load losses include permanent (conditionally permanent) no-load losses of electrical equipment, power line corona, etc. They change slightly when the load of the element changes. The load loss is the part of the loss that depends on the load of the element.

According to data in 2005, the level of losses in electric networks in Russia amounted to 13.15% of supply to the network, in 2011 this figure decreased to 8.7%. This value characterizes the efficiency of functioning and the technical condition of networks, so it is interesting to compare it with the indicators of other countries presented in Fig. 1.1. The lowest losses of 4.1-5.5% are characterized by the Netherlands, Germany, Finland, South Korea, Japan and the United States, which is the result of technical solutions and a targeted policy.

As domestic and foreign experience shows, crisis phenomena in general and in the energy sector in particular negatively affect losses in electrical networks, which in a number of countries (Fig. 1.1) exceed 20%. The low standard of living is a consequence of the low level of economic development and, accordingly, the lack of funds necessary to restore order. There are no funds for the installation of modern metering devices. There are no funds for decent wages for energy sales inspectors, and there is not enough investment in the network infrastructure. There are understandable motives of the population, which is extremely constrained in material resources, to try to save on electricity bills. In Kalmykia, for example, losses exceed 30%; on Sakhalin, losses are more than 30%.

Rice. 1.1.

According to international experts, the relative losses of electricity during its transmission and distribution are considered satisfactory (optimal) if they do not exceed 4-5%. In international practice, it is generally accepted that if the losses of electricity in the main and distribution networks exceed 8-9% in total, then such transmission and distribution of electricity is unprofitable due to the additional consumption of millions of tons of fuel to compensate for electricity losses, increased retail tariffs, increased prices on industrial and agricultural products, as well as due to additional load on the networks, a decrease in the quality of electricity in terms of voltage, etc. . Losses at the level of 10% can be considered the maximum allowable from the point of view of the physics of the process of transmission of electricity through networks for most countries with developed economies.

Actual (reported) electricity losses are defined as the difference between electricity supplied to the electrical network and usefully supplied to consumers. These losses include components of a different nature: losses in network elements that are purely physical in nature, the consumption of electricity for the operation of equipment installed at substations and ensuring the transmission of electricity, errors in recording electricity by metering devices and, finally, theft of electricity, non-payment or incomplete payment meter readings, etc.

The actual loss can be divided into four components:

- technical losses of electricity, are formed during the transmission of electricity through electric networks, due to physical processes in wires, cables and electrical equipment;

- the amount of electricity spent for the own needs of substations , necessary to ensure the operation of the technological equipment of substations and the life of the maintenance personnel, determined by the readings of the meters installed at the TSN;

– power losses due to measurement errors (instrumental losses) ;

- commercial losses due to theft of electricity, interference in the connection scheme, exposure to metering devices with a magnet, inconsistency in meter readings with payment for electricity by household consumers and other reasons in the field of organizing control over energy consumption. Their value is determined as the difference between the actual (reported) losses and the sum of the first three components:

The first three components of the loss structure are due to the technological needs of the process of transmission of electricity through networks and instrumental accounting of its receipt and release. The sum of these components is well described by the term technological losses. The fourth component - commercial losses - is the impact of the "human factor" and includes all its manifestations: deliberate theft of electricity by some subscribers by changing meter readings, non-payment or incomplete payment of meter readings, etc.

Criteria for attributing part of the electricity to losses can be of a physical and economic nature.

The sum of technical losses, consumption of electricity for substations own needs and commercial losses can be called physical losses of electricity. These components are really related to the physics of energy distribution over the network. At the same time, the first two components of physical losses relate to the technology of electricity transmission through networks, and the third - to the technology for controlling the amount of electricity transmitted.

Economics defines losses as the difference between supply to the network and useful supply to consumers. It should be noted that useful supply is not only the part of the electricity that was paid for, but also the part for which the energy sales company was billed. If the subscriber's consumption was not recorded in the current billing period (bypass, payment, AIP, etc.), then the accrual will be made according to the average monthly consumption.

From the point of view of economics, the consumption of electricity for substations' own needs is no different from the consumption in network elements for the transmission of the rest of the electricity to consumers.

The underestimation of the volume of usefully supplied electricity is the same economic loss as the two components described above. The same can be said about the theft of electricity. Thus, all four components of losses described above are the same from an economic point of view.

Technical losses of electricity can be represented by the following structural components:

- no-load losses, including losses in electricity in power transformers, compensating devices (CU), voltage transformers, meters and devices for connecting high-frequency communications, as well as losses in the insulation of cable lines;

– load losses in substation equipment. These include losses in lines and power transformers, as well as losses in measuring complexes of electrical energy,

- climatic losses, which include two types of losses: corona losses and losses due to leakage currents in the insulators of overhead lines and substations. Both types are weather dependent.

Technical losses in electrical networks of power supply organizations (power systems) must be calculated for three voltage ranges:

- in supply networks with voltages of 35 kV and above;

- in distribution networks of medium voltage 6 - 10 kV;

– in distribution networks of low voltage 0.38 kV.

Distribution networks 0.38 - 6 - 10 kV, operated by the area of electrical networks (RES), are characterized by a significant share of electricity losses. This is due to the peculiarities of the length, construction, functioning, organization of operation of this type of networks: a large number of elements, branching of circuits, insufficient provision of metering devices of the corresponding class, etc.

At present, technical losses in networks of 0.38 - 6 - 10 kV for each distribution network of power systems are calculated monthly and summarized for a year. The obtained values of losses are used to calculate the planned standard for electricity losses for the next year.