Electricity losses. Thesis: Electricity losses in electrical distribution networks

Electricity losses in electrical networks
Electricity losses in electrical networks are the most important indicator of the efficiency of their operation, a visual indicator of the state of the electricity metering system, and the efficiency of energy sales activities of energy supply organizations.
This indicator increasingly clearly indicates accumulating problems that require urgent solutions in the development, reconstruction and technical re-equipment of electrical networks, improvement of methods and means of their operation and management, increasing the accuracy of electricity metering, the efficiency of collecting funds for electricity supplied to consumers, etc. .P.
According to international experts, the relative losses of electricity during its transmission and distribution in the electrical networks of most countries can be considered satisfactory if they do not exceed 4-5%. Electricity losses at the level of 10% can be considered the maximum permissible from the point of view of the physics of electricity transmission through networks.
It is becoming more and more obvious that the sharp aggravation of the problem of reducing electricity losses in electrical networks requires an active search for new ways to solve it, new approaches to the selection of appropriate measures, and most importantly, to the organization of work to reduce losses.
Due to a sharp reduction in investments in the development and technical re-equipment of electrical networks, in improving systems for managing their modes and electricity metering, a number of negative trends have emerged that negatively affect the level of losses in networks, such as: outdated equipment, physical and moral wear and tear of electricity metering equipment, non-compliance installed equipment transmitted power.
From the above it follows that against the backdrop of ongoing changes in the economic mechanism in the energy sector and the economic crisis in the country, the problem of reducing electricity losses in electrical networks not only has not lost its relevance, but, on the contrary, has become one of the tasks of ensuring the financial stability of energy supply organizations .
Some definitions:
Absolute power losses--– the difference in electricity supplied to the electrical network and usefully supplied to consumers.
Technical losses of electricity– losses caused by physical processes of transmission, distribution and transformation of electricity are determined by calculation.
Technical losses are divided into conditionally constant and variable (depending on the load).
Commercial losses of electricity are losses defined as the difference between absolute and technical losses.

STRUCTURE OF COMMERCIAL ELECTRICITY LOSSES
Ideally, commercial losses of electricity in the electrical network should be zero. It is obvious, however, that in real conditions, supply to the network, useful supply and technical losses are determined with errors. The differences in these errors are actually the structural components of commercial losses. They should be minimized as much as possible by implementing appropriate measures. If this is not possible, it is necessary to make amendments to the electricity meter readings to compensate for systematic errors in electricity measurements.

Errors in measurements of electricity supplied to the network and usefully supplied to consumers.
The error in electricity measurements can generally be divided into
many components. Let's consider the most significant components of the errors of the measuring complexes (MC), which may include: a current transformer (CT), a voltage transformer (VT), an electricity meter (EM), a line connecting the ESS to the VT.
The main components of measurement errors of electricity supplied to the network and usefully supplied electricity include:

errors in electricity measurements under normal conditions
IR work, determined by the accuracy classes of CT, VT and SE;
additional errors in electricity measurements in real operating conditions of the IC, due to:
power factor lower than the standard
load (additional angular error); .
influence on solar cells of magnetic and electromagnetic fields of various frequencies;
underload and overload of CTs, HP and SE;
asymmetry and level of voltage supplied to the IR;
operation of solar power in unheated rooms with unacceptably low
what temperature, etc.;
insufficient sensitivity of solar cells at low loads,
especially at night;
systematic errors caused by excess service life of the IC.
errors associated with incorrect connection diagrams of electricity meters, CTs and VTs, in particular, phasing violations of meter connections;
errors caused by faulty electricity metering devices;
errors in reading electricity meters due to:
errors or intentional distortions in recordings of testimony;
lack of timeliness or failure to meet deadlines
taking meter readings, violation of meter bypass schedules
chikov;
errors in determining the conversion factors of readings
electricity meters.
It should be noted that with the same signs of the components of the measurement errors of supply to the network and useful supply, commercial losses will decrease, and if they are different, they will increase. This means that from the point of view of reducing commercial losses of electricity, it is necessary to pursue a coordinated technical policy to increase the accuracy of measurements of supply to the network and useful supply. In particular, if we, for example, unilaterally reduce the systematic negative measurement error (modernize the accounting system) without changing the measurement error, commercial losses will increase, which, by the way, occurs in practice.

The more electricity losses network companies have, the higher the price of electricity, the constant increase of which places a heavy burden on the consumer.

General information

The structure of actual electricity losses consists of many components. Previously, they were often combined into two large groups: technical and commercial losses. The first included load, conditionally constant losses and electricity consumption for the own needs of substations. All other losses, including instrumental measurement errors, were attributed to the second group of losses. There are certain conventions in this classification. Electricity consumption for own needs is not inherently a “pure” technical loss, and is taken into account by electric meters. Also, metrological errors, unlike other components of commercial losses, have a different origin. Therefore, “commercial losses” were initially interpreted quite broadly; there is even such a definition as “acceptable level of commercial losses” - the value of commercial losses of electricity due to errors in the electricity metering system (electricity meters, current and voltage transformers) when the metering system complies with the requirements of the Electrical Electricity Regulations.

Currently, when classifying electricity losses, the term “technological losses of electricity” is more often used, the definition of which is established by Order of the Ministry of Energy of the Russian Federation dated December 30, 2008 No. 326 “On organization in the Ministry of Energy Russian Federation work to approve standards for technological losses of electricity during its transmission through electrical networks.” The collective expression “commercial losses of electricity” is currently not enshrined in legislation, but is found in industry regulatory and technical documents. In one of them, commercial losses are understood as the difference between reporting and technical losses, while “technical losses of electricity” are considered to be all “technological consumption of electricity for its transport through electrical networks, determined by calculation.”

Also, in the form of federal statistical observation No. 23-N “Information on production and distribution electrical energy", approved by Order of the Federal State Statistics Service dated 01.10.2012 No. 509, the reporting indicator “commercial losses” is used. Its definition within the framework of form 23-N sounds like “data on the amount of electricity not paid for by subscribers”, without providing a calculation formula In industry reporting documents of network companies, for example, in forms 2-reg, 46-EE (transmission), only actual losses are indicated, and in the layouts of 7-energo a detailed structure of technological losses. Commercial losses, as well as non-technical or non-technological, in these forms are not indicated.

In the tables for justification and examination of technological losses of electricity for a regulated period, filled out by network organizations, the mathematical difference between actual and technological losses of electricity is called “non-technical losses of electricity”, although it is more logical to call them “non-technological”.

To avoid confusion in the terminology used, in the aggregated structure of actual electricity losses it is more correct to designate two groups:

1. Technological losses.

2. Commercial losses.

Technological losses include technical losses in electrical networks caused by physical processes occurring during the transmission of electricity, electricity consumption for the own needs of substations, and losses caused by permissible errors in the electricity metering system.

They are not losses of the enterprise in the fullest sense of the word, since the cost of their standard volume is taken into account in the tariff for electricity transmission. Funds to cover financial costs associated with the purchase of electricity to compensate for technological losses within the established standard are received by the network company as part of the collected revenue for the transmission of electricity.

Technical losses of electricity can be calculated according to the laws of electrical engineering, permissible errors of metering devices - based on their metrological characteristics, and consumption for substations’ own needs can be determined based on the readings of electricity meters.

Commercial losses cannot be measured with instruments and calculated using independent formulas. They are defined mathematically as the difference between actual and technological losses of electricity and are not subject to inclusion in the standard for electricity losses. The costs associated with their payment are not compensated by tariff regulation.

The applied definition of “commercial” (English: “commerce” - “trade”) for this type of loss emphasizes the connection of the loss with the process of turnover of goods, which is electricity. Electricity losses classified as commercial are mostly electricity consumption, which various reasons not documented. Therefore, it is not taken into account as a return from the networks, and is not presented to any consumers for payment.

In accordance with current legislation, network organizations are required to pay for actual losses of electrical energy that occur in their network facilities, and therefore, for commercial losses in their composition. Commercial losses of electricity, unlike technological ones, are a direct financial loss for network companies. Being, on the one hand, the reason for the monetary expenses of the network enterprise, they are at the same time its lost profit from unpaid electricity transmission. Therefore, network organizations, to a greater extent than other participants in the electricity market, are interested in the most accurate accounting of electricity and the correct calculation of its volumes at delivery points at the borders of their balance sheet.

We can talk about the incorrectness of shifting all financial responsibility for commercial losses of electricity to network companies, since the causes of their occurrence, as well as the effectiveness of their identification and elimination, depend not only on the electric network companies. But the fact remains: commercial losses of electricity are a “headache” primarily for network organizations.

At the same time, the imperfection of the legislative and legal framework, the lack of direct contractual relations between network enterprises on energy supply with consumers, insufficient funding and the impossibility of significantly increasing the staff of employees monitoring electricity consumption, limit the ability of network organizations to identify and eliminate the causes of commercial losses of electricity.

Causes of commercial power losses

The amount of commercial electricity losses depends on the values ​​of other structural indicators of the electricity balance. To find out the volume of commercial electricity losses for certain period, you must first draw up a balance of electricity for the section of the electrical network in question, determine the actual losses and calculate all the components of technological losses of electricity. Further analysis of electricity losses helps to localize their areas and identify the causes of their occurrence for the subsequent selection of measures to reduce them.

The main causes of commercial electricity losses can be grouped into the following groups:

1. Instrumental, associated with errors in measuring the amount of electricity.

2. Errors in determining the values ​​of electricity supply to the network and useful supply to consumers.

4. Errors in calculating technological losses of electricity.

1. Work measuring systems electricity is accompanied by an instrumental error, the magnitude of which depends on the actual technical characteristics of metering devices and the actual conditions of their operation. The requirements for measuring instruments established by legislative and regulatory technical documents ultimately affect the maximum permissible amount of under-accounting for electricity, which is included in the standard process losses. Deviation of actual under-metering of electricity from the calculated one permissible value refers to commercial losses.

The main reasons leading to the emergence of commercial “instrumental” losses:

Overload of secondary circuits of current (CT) and voltage (VT) instrument transformers,

Low power factor (cos φ) of the measured load,

The influence of magnetic and electromagnetic fields of various frequencies on the electricity meter,

Asymmetry and significant voltage drop in secondary measuring circuits,

Deviations from the permissible temperature regime work,

Insufficient sensitivity threshold of electricity meters,

Inflated transformation ratio of measuring CTs,

Systematic errors of induction electricity meters.

Also, the measurement results are influenced by the following factors, the presence of which is largely determined by the existing level of monitoring in the network organization of the condition and correct operation of the fleet of metering devices used:

Excessive service life of measuring systems,

Malfunction of metering devices,

Errors in the installation of metering devices, including incorrect connection diagrams, installation of measuring CTs with different transformation ratios in different phases of the same connection, etc.

There are still outdated induction electricity meters of accuracy class 2.5 that have exhausted their service life. Moreover, such metering devices are found not only among consumers - citizens, but also among consumers - legal entities.

According to the law in force until 2007. GOST 6570-96 “Inductive active and reactive energy meters”, the service life of electricity meters with accuracy class 2.5 was limited by the first calibration interval, and from 07/01/97 the production of meters of class 2.5 was discontinued.

Induction meters of accuracy class 2.5 are excluded from the State Register of Measuring Instruments; they are not produced and are not accepted for verification. The verification period for a single-phase induction meter is 16 years, and for a three-phase one – 4 years. Therefore, according to the timing of the verification interval, three-phase induction electricity meters of accuracy class 2.5 should not be used for commercial electricity metering for several years.

The currently valid GOST R 52321-2005 (IEC 62053-11:2003) applies to electromechanical (induction) watt-hour meters of accuracy classes 0.5; 1 and 2. For induction electric meters of class 2.5 there are currently no existing regulatory documents, establishing metrological requirements.

We can conclude that the current use of single-phase induction electricity meters with accuracy class 2.5 as measuring instruments does not comply with the provisions of Federal Law No. 102-FZ of June 26, 2008 “On ensuring the uniformity of measurements.”

2. Errors in determining the values ​​of electricity supply to the network and useful supply to consumers are due to the following factors:

Distortions of data on actual readings of electricity meters at any stage of the operational process. This includes errors in visual meter readings, inaccurate data transfer, incorrect entry of information into electronic databases, etc.

Inconsistency of information about the metering devices used, calculated coefficients, and their actual data. Errors can occur already at the stage of concluding a contract, as well as when information is entered inaccurately into electronic databases, their untimely updating, etc. This should also include cases of replacing metering devices without simultaneously drawing up reports and recording the readings taken and installed meter, transformation ratios of instrument transformers.

Unsettled contractual terms in the field of electricity supply and the provision of electricity transmission services in relation to the composition of delivery points, metering devices and the applied algorithms for calculating losses in electrical equipment when they are installed not at the border of the balance sheet. Such situations can lead not only to errors in calculations, especially when changing the owner of a facility, restructuring of organizations that consume electricity, etc., but also to the actual “non-contractual” power supply of facilities in the absence of official inclusion of specific delivery points in energy supply or service contracts for electricity transmission.

Lack of simultaneity in taking readings from electricity meters, both at consumers and at points of electricity supply to the network (return from the network).

Inconsistency between the calendar periods for identifying and including unaccounted for electricity in the volume of its transmission.

Installation of metering devices not on the balance sheet boundary of the networks, inaccuracies and errors in the applied algorithms for calculating electrical energy losses in network elements from the balance sheet border to the measurement point, or the absence of such algorithms for “additional calculation” of electricity losses.

Determination of the amount of transmitted electricity by calculation methods in the absence of metering devices or its malfunction.

- “Unmetered” power supply, with determination of the amount of electricity consumed by the installed capacity of electrical receivers, as well as with the use of other regulatory and calculation methods. Such cases violate the provisions of Federal Law No. 261 - Federal Law "On energy saving and increasing energy efficiency and on introducing amendments to certain legislative acts of the Russian Federation" dated November 23, 2009, regarding the installation of electrical energy metering devices and their commissioning.

Insufficient equipment of electrical energy metering devices at the boundaries of the balance sheet of electrical networks, incl. with multi-apartment residential buildings.

The presence of ownerless networks, the lack of work to identify their balance holders.

Application of replacement (calculated) information during the period of under-metering of electricity in the event of a malfunction of the meter.

3. Unauthorized power consumption.

This category includes the so-called “theft” of electricity, which includes unauthorized connection to electrical networks, connection of electrical receivers in addition to the electric meter, as well as any interference with the operation of metering devices and other actions with the aim of understating the electricity meter readings. This should also include untimely notification to the energy supply organization about malfunctions of metering devices.

Unauthorized electricity consumption often accounts for the bulk of commercial losses, especially in the 0.4 kV network. In all possible ways Electricity theft is mostly carried out by household consumers, especially in the private residential sector, but there are cases of electricity theft by industrial and commercial enterprises, mostly small ones.

The volume of electricity theft increases during periods low temperature air, which indicates that the bulk of the unaccounted electricity during this period is spent on heating.

4. Errors in calculations of technological losses of electricity:

Since commercial losses are a calculated value obtained mathematically, errors in determining technological energy consumption have a direct impact on the value of commercial losses. Errors in calculations of technological losses are determined by the calculation methodology used, completeness and reliability of information. The accuracy of calculations of load losses of electricity carried out using methods of operational calculations or calculation days is undoubtedly higher than when calculating using the method of average loads or generalized network parameters. In addition, the actual technical parameters of the electrical network elements often have deviations from the reference and passport values ​​used in the calculations, which is associated with the duration of their operation and the actual technical condition electrical equipment. Parameter Information electrical modes network operation, electricity consumption for own needs, also does not have ideal reliability, but contains a certain amount of error. All this determines the total error in calculations of technological losses. The higher their accuracy, the more accurate the calculation of commercial electricity losses will be.

Ways to reduce commercial losses

Measures aimed at reducing commercial electricity losses are determined by the reasons for their occurrence. Many measures to reduce commercial electricity losses are covered in sufficient detail in the scientific and technical literature. The main list of measures aimed at improving electricity metering devices is given in the industry instructions.

Measures to reduce commercial electricity losses can be divided into two groups:

1. Organizational, increasing the accuracy of calculations of electricity balance indicators, incl. useful holiday to consumers.

2. Technical, mainly related to the maintenance and improvement of electricity metering systems.

The main organizational activities include the following:

- Checking the availability of acts of delineation of balance sheet ownership by points of supply of external and internal sections of electricity metering, timely recording of all points of supply of electricity, checking for compliance with contractual terms.

- Formation and timely updating of databases on electricity consumers and metering groups, linking them to specific elements of the electrical network diagram.

- Reconciliation of actual technical characteristics of metering devices and those used in calculations.

- Checking the availability and correctness of algorithms for “additional calculation” of losses when installing metering devices not at the balance sheet boundary.

- Timely reconciliation of meter readings, maximum automation of operational activities for calculating electricity volumes to eliminate the influence of the “human factor”.

- Elimination of the practice of “unmetered” electricity supply.

- Carrying out calculations of technological losses of electricity, increasing the accuracy of their calculations.

- Monitoring actual imbalances of electricity at substations, timely taking measures to eliminate excess deviations.

- Calculations of “feeder” balances of electricity in the network, balances for 10(6)/0.4 kV transformer substations, in 0.4 kV lines, to identify “hot spots” of commercial electricity losses.

- Detection of electricity theft.

- Providing personnel to check metering devices and identify electricity thefts, necessary tool and inventory. Training in methods of detecting electricity theft, increasing motivation with additional material rewards taking into account work efficiency.

The main technical measures aimed at reducing commercial electricity losses include the following:

- Inventory of electric power measuring systems, marking them with visual control signs, sealing of electric meters, measuring transformers, installation and sealing of protective covers of terminal clamps of measuring circuits.

- Timely instrumental testing of metering devices, their verification and calibration.

- Replacement of electricity meters and instrument transformers with metering devices with increased accuracy classes.

- Elimination of underload and overload of current and voltage transformers, unacceptable level of voltage losses in VT measuring circuits.

- Installation of metering devices at the boundaries of the balance sheet, incl. electricity metering points at the boundary of the balance sheet section passing along power lines.

- Improving the calculation and technical accounting of electricity, replacing outdated measuring instruments, as well as metering devices with technical parameters that do not comply with legislative and regulatory-technical requirements.

- Installation of metering devices outside private property.

- Replacement of “bare” aluminum wires of overhead lines - 0.4 kV with SIP, replacement of inputs into buildings made with bare wire with coaxial cables.

- Introduction of automated information and measurement systems for commercial electricity metering (AIIS KUE), both for industrial and household consumers.

The last of these measures is the most effective in reducing commercial electricity losses, since it is comprehensive solution main key tasks, ensuring reliable and remote receipt of information from each measurement point, carrying out constant monitoring of the serviceability of metering devices. In addition, the implementation of unauthorized power consumption is made as difficult as possible, and the identification of “hot spots” of losses in as soon as possible with minimal labor costs. The limiting factor for widespread automation of electricity metering is the high cost of AIMS KUE systems. The implementation of this activity can be carried out in stages, identifying priority nodes of the electrical network for metering automation based on a preliminary energy survey with an assessment of the economic efficiency of the project implementation.

To address issues of reducing commercial electricity losses, it is also necessary to improve the regulatory framework in the field of energy supply and electricity metering. In particular, the application of consumption standards utilities on electricity supply should encourage subscribers to install metering devices as quickly as possible (eliminate their malfunctions), and not to calculate the benefits of their absence. The procedure for admitting representatives of network companies to check the condition of metering devices and take their readings from consumers, primarily individuals, should be as simple as possible, and liability for unauthorized power consumption should be increased.

Conclusion

Commercial losses of electricity are a serious financial loss for network enterprises and divert their funds from solving other pressing problems in the field of electricity supply.

Reducing commercial electricity losses is a complex task, which in its solution requires the development of specific measures based on a preliminary energy survey and determination of the actual structure of electricity losses and their causes.

ANO "Energy Saving Agency UR" carries out all work related to energy inspection of enterprises, monitoring of electricity consumption, calculation and standardization of technological losses of electricity, determination of the structure of electricity losses and development of measures to reduce them.

LITERATURE:

1. RD 34.09.254 “Instructions for reducing the technological consumption of electrical energy for transmission through electrical networks of power systems and energy associations. And 34-70-028-86”, M., SPO Soyuztekhenergo, 1987

2. RD 153-34.0-09.166-00 “Standard program for conducting energy surveys of electrical network divisions of JSC-Energo”, SPO ORGRES, 2000

3. Order of the Ministry of Energy of the Russian Federation dated December 30, 2008 No. 326 “On the organization in the Ministry of Energy of the Russian Federation of work to approve standards for technological losses of electricity during its transmission through electrical networks”

4. Rules for non-discriminatory access to services for the transmission of electrical energy and the provision of these services (approved by Decree of the Government of the Russian Federation of December 27, 2004 No. 861)

5. Vorotnitsky V.E., Kalinkina M.A. Calculation, regulation and reduction of electricity losses in electrical networks (Training and methodological manual) - M.: IUE GUU, VIPKenergo, IPKgossluzhby, 2003

6. Vorotnitsky V.E., Zaslonov S.V., Kalinkina M.A., Parinov I.A., Turkina O.V. Methods and tools for calculating, analyzing and reducing losses of electrical energy during its transmission through electrical networks M.: DialogueElectro, 2006

Losses in electrical networks are considered to be the difference between the transmitted electricity from the manufacturer to the recorded consumed electricity of the consumer. Losses occur on power lines, in power transformers, due to eddy currents when consuming devices with reactive loads, as well as due to poor insulation of conductors and theft of unaccounted for electricity. In this article we will try to talk in detail about the types of electricity losses in electrical networks, and also consider measures to reduce them.

Distance from power plant to supplying organizations

Accounting and payment of all types of losses is regulated by the legislative act: “Resolution of the Government of the Russian Federation of December 27, 2004 N 861 (as amended on February 22, 2016) “On approval of the Rules for non-discriminatory access to services for the transmission of electrical energy and the provision of these services...” clause VI. The procedure for determining losses in electrical networks and paying for these losses. If you want to figure out who should pay for part of the lost energy, we recommend studying this act.

When transmitting electricity over long distances from the manufacturer to the supplier to the consumer, part of the energy is lost for many reasons, one of which is the voltage consumed by ordinary consumers (it is 220 or 380 V). If such voltage is transported directly from power plant generators, then it is necessary to lay electrical networks with a wire diameter that will provide everyone with the necessary current at the specified parameters. The wires will be very thick. It will be impossible to hang them on power lines due to heavy weight, laying it in the ground will also be expensive.

You can find out more about this in our article!

To eliminate this factor, high-voltage power lines are used in distribution networks. A simple calculation formula is: P=I*U. Power is equal to the product of current and voltage.

Power consumption, W	Voltage, V	Current, A
100 000	220	454,55
100 000	10 000	10

By increasing the voltage when transmitting electricity in electrical networks, the current can be significantly reduced, which will make it possible to use wires with a much smaller diameter. Underwater rock of this transformation is that there are losses in transformers that someone has to pay for. Transmitting electricity at such a voltage, it is significantly lost due to poor contact of conductors, which increase their resistance over time. Losses increase with increasing air humidity - the leakage current on the insulators and on the corona increases. Losses in cable lines also increase with a decrease in wire insulation parameters.

The supplier transferred the energy to the supplying organization. That, in turn, must bring the parameters to the required indicators: convert the resulting product to a voltage of 6-10 kV, distribute cable lines point by point, and then convert it again to a voltage of 0.4 kV. Transformation losses occur again when operating 6-10 kV and 0.4 kV transformers. Electricity is delivered to the household consumer at the required voltage - 380 V or 220 V. Any transformer has its own efficiency and is designed for a certain load. If the power consumption is more or less than the calculated power, losses in electrical networks increase regardless of the wishes of the supplier.

The next pitfall is the discrepancy in the power of the transformer that converts 6-10 kV to 220V. If consumers take more energy than the rated capacity of the transformer, it either fails or will not be able to provide required parameters at the exit. As a result of a decrease in network voltage, electrical appliances operate in violation of the specified conditions and, as a result, increase consumption.

Measures to reduce technical losses of electricity in power supply systems are discussed in detail in the video:

Home conditions

The consumer received his 220/380 V at the meter. Now the electrical energy lost after the meter falls on the end user.

It consists of:

1. Losses when the calculated consumption parameters are exceeded.
2. Poor contact in switching devices (switches, starters, switches, lamp sockets, plugs, sockets).
3. Capacitive nature of the load.
4. Inductive nature of the load.
5. Use of outdated lighting systems, refrigerators and other old equipment.

Let's consider measures to reduce electricity losses in houses and apartments.

Item 1 - there is only one way to combat this type of loss: the use of conductors corresponding to the load. In existing networks, it is necessary to monitor the compliance of wire parameters and power consumption. If it is impossible to adjust these parameters and bring them back to normal, you must accept the fact that energy is lost on heating the wires, as a result of which the parameters of their insulation change and the likelihood of a fire in the room increases. We talked about this in the corresponding article.

P.2 - poor contact: in switches - this is used modern designs with good non-oxidizing contacts. Any oxide increases resistance. The same method applies to starters. Switches - the on-off system must use metal that can withstand moisture and elevated temperatures well. Contact must be ensured by good pressing of one pole to the other.

P.3, P.4 - reactive load. All electrical appliances that do not belong to incandescent lamps or old-style electric stoves have a reactive component of electricity consumption. Any inductance, when voltage is applied to it, resists the passage of current through it due to the resulting magnetic induction. Over time, electromagnetic induction, which prevented the passage of current, helps its passage and adds some energy to the network, which is harmful to general networks. So-called eddy currents arise, which distort the true readings of electricity meters and make negative changes in the parameters of the supplied electricity. The same thing happens with a capacitive load. The resulting eddy currents spoil the parameters of the electricity supplied to the consumer. The struggle is the use of special reactive energy compensators, depending on the load parameters.

P.5. Use of outdated lighting systems (incandescent light bulbs). Their efficiency has a maximum value of 3-5%, and maybe less. The remaining 95% goes to heating the filament and, as a result, heating environment and radiation not perceived by the human eye. Therefore, improve this type lighting became impractical. Other types of lighting appeared - fluorescent lamps, which became widely used in Lately. The efficiency of fluorescent lamps reaches 7%, and LED lamps up to 20%. The use of the latter will save energy right now and during operation due to long term service life - up to 50,000 hours (incandescent lamp - 1,000 hours).

Separately, I would like to note that you can reduce electrical energy losses in your home using. In addition, as we have already said, electricity is lost when it is stolen. If you notice that, you need to immediately take appropriate measures. We told you where to call for help in the corresponding article to which we referred!

The methods of reducing power consumption discussed above reduce the load on electrical wiring in the house and, as a result, reduce losses in the electrical network. As you already understand, control methods are most widely disclosed for household consumers because not every owner of an apartment or house knows about possible losses electricity, and supplying organizations employ workers specially trained on this topic who are able to deal with such problems.

In electrical networks there are large actual losses of electricity.

Of the total losses, losses in power transformers of MUP "PES" are approximately 1.7%. Electricity losses in power transmission lines with a voltage of 6-10 kV are about 4.0%. Electricity losses in 0.4 kV networks are 9-10%.

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

The main causes of technical losses are:

Deterioration of electrical equipment;

Use of outdated types of electrical equipment;

Inconsistency of the electrical equipment used with the existing loads;

Non-optimal steady-state conditions in distribution networks by level
voltage and reactive power.

The main causes of commercial losses are:

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

Non-contractual and unaccounted for electricity consumption (theft);

Distortion of the volume of electricity supplied to consumers.

ACTUAL ELECTRICITY LOSSES

IN MUP "PODILSKAYA ELECTRIC GRID"

STRUCTURE OF ACTUAL ELECTRICITY LOSSES

Technological losses of electricity (hereinafter referred to as TEL) during its transmission through TSO electrical networks include technical losses in lines and equipment of electrical networks caused by physical processes occurring during the transmission of electricity in accordance with the technical characteristics and operating modes of lines and equipment, taking into account consumption electricity for the own needs of substations and losses due to permissible errors in the electricity metering system. The volume (quantity) of technological losses of electricity for the purpose of determining the standard for technological losses of electricity during its transmission through electric networks is calculated in accordance with the instructions for organizing in the Ministry of Energy of the Russian Federation work on the calculation and justification of standards for technological losses of electricity during its transmission through electric networks, approved by order No. 000 of 01/01/2001.

Methods for calculating standard losses of electrical energy

Basic Concepts

1. Reception of electrical energy into the network

2. Return of electrical energy from the network

4. Actual (reported) electricity losses in absolute units

6. Technical losses of electricity

9. Standard for technological losses of electricity in absolute units

11. Standard absolute electricity losses

Calculation of losses in electrical network equipment

ü Electricity losses in the overhead line

ü Electricity losses in the cable line

ü Electricity losses in transformers (autotransformers)

ü Electricity losses in current-limiting reactors

Conditionally permanent losses of electricity

Ü losses in steel of power transformers and autotransformers;

Ü losses in steel of shunt reactors;

Ü corona losses in overhead lines 110 kV and above;

Ü losses in capacitor banks (BCB) and static thyristor compensators;

Ü losses in synchronous compensators (SC);

Ü losses in surge suppressors;

Ü electricity losses in direct-connection meters;

Ü losses in current and voltage measuring transformers;

Ü losses in insulation of cable lines;

Ü losses from leakage currents through overhead line insulators;

Ü losses in connecting wires and busbars of substations;

Ü electricity consumption for melting ice;

Ü electricity consumption for the auxiliary needs of substations, taking into account losses in steel and copper of auxiliary transformers if the accounting does not coincide with the balance sheet boundary.

Variable power losses

Ü load losses of electricity in transformers and autotransformers

Ü load losses of electricity in overhead and cable lines

Ü electricity losses in current-limiting reactors

Methods for calculating variable losses

Method of operational calculations of steady-state conditions using data from operational control systems (OIC)

Method for calculating losses based on the data of the design day (using operational data for characteristic days)

Method for calculating losses based on average loads

Method for calculating losses under maximum network load using the number of hours of greatest power losses

Estimated calculation methods

Method of operational calculations

Electricity losses over a time interval in a three-winding transformer

Settlement day method

Electricity losses for the billing period

Graph shape factor

Average load method

The division of losses into components can be carried out according to different criteria: the nature of losses (constant, variable), voltage classes, groups of elements, production departments, etc. For the purposes of analysis and standardization of losses, it is advisable to use an enlarged structure of electricity losses, in which losses are divided into components based on their physical nature and the specific methods for determining their quantitative values.

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

1) technical losses of electricity caused by physical processes occurring during the transmission of electricity through electrical networks and expressed in the conversion of part of the electricity into heat in network elements. Theoretically, technical losses can be measured by installing appropriate instruments that record the supply and release of electricity at the facility in question. In practice, it is impossible to estimate their actual value with acceptable accuracy using measuring instruments. For an individual element, this is explained by the relatively small value of losses, comparable to the error of metering devices. For example, measuring the loss of a line whose actual energy loss is 2% using instruments that have an accuracy of ±0.5% may result in a result of 1.5 to 2.5%. For objects that have a large number of points of receipt and release of electricity (electrical network), installing special devices at all points and ensuring synchronous taking of their readings is practically unrealistic (especially for determining power losses). Electricity meters are already installed at all these points, but we cannot say that the difference in their readings is the actual value of technical losses. This is due to the territorial dispersion of numerous devices and the impossibility of ensuring complete control over the correctness of their readings and the absence of cases of influence on them by other persons. The difference in the readings of these devices represents the actual losses, from which the required component should be isolated. Therefore, it can be argued that it is impossible to measure technical losses at a real network facility. Their value can only be obtained by calculation based on the known laws of electrical engineering;

2) electricity consumption at MV substations necessary to ensure operation technological equipment substations and the life of maintenance personnel. This consumption is recorded by meters installed on the MV transformers of the substations;

3) losses of electricity caused by errors in its measurement (under-metering of electricity, metrological losses). These losses are obtained by calculation based on data on the metrological characteristics and operating modes of instruments used to measure energy (CTs, VTs and the electricity meters themselves). The calculation of metrological losses includes all devices for metering electricity supply from the network, including meters for metering electricity consumption at MV substations;

4) commercial losses caused by theft of electricity, discrepancies between meter readings and electricity payments by household consumers and other reasons in the area 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 actual losses and the sum of the first three components.

The first three components of the enlarged structure of losses are determined by the technological needs of the process of transmitting electricity through networks and instrumental accounting of its receipt and supply. The sum of these components is well described by the term technological losses. The fourth component - commercial losses - represents the impact of the “human factor” and includes all manifestations of such impact: deliberate theft of electricity by some subscribers by changing meter readings, energy consumption other than meters, non-payment or incomplete payment of meter readings, determination of receipt and supply of electricity at some metering points by calculation (if the boundaries of the balance sheet of the networks and the installation locations of metering devices do not coincide), etc.

The structure of losses, in which the enlarged components of losses are grouped according to various criteria, is shown in Fig. 1.1.

Each loss component has its own more detailed structure.

Load losses include losses:

• in transmission line wires;
• power transformers and autotransformers;
• current-limiting reactors;
• high frequency communication barriers;
• current transformers;
• connecting wires and buses of switchgears (RU) of substations.

The last two components, due to the lack of practice in their element-by-element calculations and their insignificant value, are usually determined on the basis of specific losses calculated for average conditions and are included in the composition of conditionally constant losses.

No-load losses include constant (load-independent) losses:

• in power transformers (autotransformers); compensating devices (synchronous and thyristor compensators, capacitor banks and shunt reactors);
• electricity metering system equipment (CT, VT, meters and connecting wires);
• valve arresters and surge suppressors;
• devices for connecting high-frequency communications (HF communications); cable insulation.

Losses due to weather conditions(climate losses) include three components:

• corona losses in overhead power lines (OL) 110 kV and above;
• losses from leakage currents along overhead line insulators;
• energy consumption for melting ice.

Electricity consumption at MV substations is determined by the operating modes of various (up to 23) types of electric power supply. This expense can be broken down into six components:

• for space heating;
• ventilation and lighting of premises;
• substation control systems and auxiliary devices of synchronous compensators;
• cooling and heating of equipment;
• operation of compressors of air switches and pneumatic drives of oil switches;
• current repair of equipment, load voltage regulation devices (OLVs), distillers, indoor ventilation switchgear(closed switchgear), heating and lighting of the entrance (other consumption).

Errors in electricity metering include components caused by errors in measuring transformers, voltage transformers and electric meters. Commercial losses can also be divided into numerous components, differing in the reasons for their occurrence.

All of these components are discussed in detail in subsequent chapters.

The criteria for classifying a portion of electricity as losses can be of a physical or economic nature. Some experts believe that electricity consumption at MV substations should be attributed to the supply of electricity, and the remaining components to losses. The consumption of MV substations in terms of the nature of the use of electricity is really no different from its use by consumers. However, this is not a reason to consider it useful supply, which is understood as electricity supplied to consumers. Electricity consumption at MV substations is the internal consumption of the network facility. In addition, this approach unreasonably assumes that the consumption of part of the energy in network elements to deliver another part of it to consumers (technical losses), in contrast to the consumption of MV substations, is not useful.

Metering devices do not change power flows through the network, they just do not accurately record them. Therefore, some experts believe that it is theoretically incorrect to classify under-accounting of electricity due to instrument errors as losses (after all, the volume of electricity does not change depending on how the instruments record it!).

One can agree with the theoretical correctness of such reasoning, as well as, at the same time, with their practical uselessness. It is not science that forces us to determine the structure of losses (for scientific research all approaches make sense), and economics. Therefore, economic criteria should be applied to analyze reported losses. From an economic point of view, losses are that part of the electricity for which its 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 money was actually received in the current account of the energy supply organization, but also that for which invoices are issued, that is, energy consumption is recorded. Billing is a practice applied to legal entities, whose energy consumption is recorded monthly. In contrast, monthly meter readings that record residential energy consumption are usually unknown. The useful supply of electricity to residential subscribers is determined by the payment received for the month, so all unpaid energy automatically falls into losses.

Electricity consumption at MV substations is not a product paid for by the end consumer, and from an economic point of view is no different from electricity consumption in network elements for transmitting the rest of it to consumers.

Underestimation of the volumes of useful electricity supplied by metering devices (under-metering) has the same economic nature as the two components described above. The same can be said about electricity theft. Therefore, all four components of losses described above are the same from an economic point of view.

Actual losses are a strictly determined value, strictly related to in cash received for sold energy. The task of “correcting” reported losses based on accounting for meter errors is meaningless, since it cannot lead to a change in the amount of money received (and not received).

A lost ruble remains lost no matter for what reason or where it was lost. But in order to accept the most effective measures To reduce losses, you need to know where and for what reasons they occur. In this regard, the main task of calculating and analyzing losses is to determine their detailed structure, identify specific areas of losses and assess the possibilities of reducing them to economically justifiable values. One of the methods for such diagnostics of losses is the analysis of electricity imbalances at facilities (substations, network enterprises) and in network organizations.