Electricity loss B. electrical networks inevitable, so it is important that they do not exceed the cost-based level. Exceeding the norms of technological consumption speaks of the problems arising. To correct the situation, it is necessary to establish the causes of the occurrence of non-target costs and choose how to reduce them. The information collected in the article describes many aspects of this difficult task.

Types and structure of losses

Losses implies the difference between electricity to be released and actually received to them. To normalize the losses and calculations of their actual magnitude, the following classification was adopted:

• Technological factor. It depends on the characteristic physical processes directly, and may vary under the influence of the load component, conditionally constant costs, as well as climatic conditions.
• Expenditures spent on operation of auxiliary equipment and provision required conditions For the operation of the technical staff.
• Commercial component. This category includes errors of accounting devices, as well as other factors causing abroad of electricity.

Below is an average sample loss chart of a typical electrocompany.

As can be seen from the graph, the greatest costs are associated with the transfer of airlines (LPP), it is about 64% of the total number of losses. In second place, the effect of corona (ionization of the air near the wires of VL and, as a result, the emergence of discharge currents between them) - 17%.

Based on the schedule presented, it can be stated that the largest percentage of non-target expenses falls on the technological factor.

The main causes of electricity loss

Having understood with the structure, we turn to the reasons that causes the non-target consumption in each of the categories listed above. Let's start with the components of the technological factor:

1. Load losses, they occur in LAP, equipment and various elements of the power grid. Such expenses are directly dependent on the total load. This component includes:

• Power losses, they are directly related to current power. That is why the transmission of electricity over long distances uses the principle of increasing several times, which contributes to proportional reduction in current, respectively, and costs.
• Consumption in transformers having a magnetic and electrical nature (). As an example, the table below shows the cost of the costs of substation voltage transformers in 10 square meters.

The inappropriate consumption in other elements is not included in this category, due to the difficulties of such calculations and minor costs. This provides for the following component.

1. Category of conditional permanent costs. It includes the costs associated with the staff exploitation of electrical equipment, and include:

• Hosting work of power plants.
• Costs in equipment that ensures the compensation of the reactive load.
• Other types of costs in various deviceswhose characteristics do not depend on the load. As an example, briskly insulation, accounting devices in 0.38 kV networks, current transformers, overvoltage limiters, etc.

Given the last factor, the cost of electricity to melt ice should be taken into account.

Support for Support Support

This category includes the cost of electrical energy on the functioning of auxiliary devices. Such equipment is necessary for the normal operation of the main nodes responsible for the transformation of electricity and its distribution. Cost fixation is carried out by accounting devices. We give a list of basic consumers belonging to this category:

• ventilation and cooling systems of transformer equipment;
• heating and ventilation of the technological room, as well as internal lighting devices;
• lighting the territories adjacent to substations;
• account charger;
• operational chains and control and control systems;
• outdoor heating systems, such as air switches control modules;
• various types of compressor equipment;
• auxiliary mechanisms;
• equipment for repair work, Communication equipment, as well as other devices.

Commercial component

Under these costs, the balance is implied between absolute (actual) and technical losses. Ideally, such a difference should strive for zero, but in practice it is not real. First of all, this is due to the peculiarities of accounting devices for the released electricity and electricity meters installed in the final consumers. We are talking about the error. There are a number of specific activities to reduce the loss of this type.

This component also includes errors in the accounts exhibited by the consumer and theft of electricity. In the first case, such a situation may occur for the following reasons:

• in the contract for the supply of electricity, incomplete or incorrect information about the consumer;
• incorrectly specified tariff;
• lack of monitoring data of accounting devices;
• errors associated with previously revised accounts, etc.

As for theft, this problem takes place in all countries. As a rule, unscrupulous consumer consumers are engaged in such illegal actions. Note that sometimes incidents and enterprises occur, but such cases are quite rare, therefore are not determining. It is characteristic that the peak of the captures falls at the cold season, and in those regions where there are problems with heat supply.

There are three ways of embezzlement (understood the reading of the accounting instrument):

1. Mechanical. Under it implies the appropriate interference with the operation of the device. This may be slowing down the rotation of the disk by direct mechanical exposure, a change in the position of the electric meter, by inclination by 45 ° (for the same purpose). Sometimes a more barbaric method is applied, namely, seals are broken, and the mechanism is delayed. An experienced specialist will instantly detect mechanical intervention.
2. Electric. This can be like an illegal connection to the airline by "sketch", the method of investing the phase of the load current, as well as the use of special devices for its full or partial compensation. In addition, there are options with shunting the current circuit of the accounting device or the phase and zero switching.
3. Magnetic. With this method, a neodymium magnet is brought to the case of an induction instrument of accounting.

Almost all modern instruments for keeping "fooling" in the ways described above will not be able. Moreover, such an intervention attempts can be fixed by the device and are brought into memory, which will lead to sad consequences.

The concept of a loss standard

Under this term implies the installation of economically reasonable criteria for inappropriate expense for a certain period. With the rationing, all components are taken into account. Each of them is carefully analyzed separately. As a result, calculations are made taking into account the actual (absolute) cost level over the past period and analysis of various possibilities that allow the identified reserves to reduce losses. That is, the standards are not static, but are regularly revised.

Under the absolute level of costs in this case, the balance is implied between transmitted electricity and technical (relative) losses. Technological loss standards are determined by appropriate calculations.

Who pays for electricity loss?

It all depends on the determining criteria. If we are talking about technological factors and expenses for supporting the work of related equipment, then the payment of losses is laid in tariffs for consumers.

It is completely different about the business of the commercial component, if the loss is exceeded, the entire economic burden is considered to be the expenses of the company that carries out electricity to consumers.

Ways to reduce losses in electrical networks

It is possible to reduce costs by optimizing the technical and commercial component. In the first case, the following measures should be taken:

• Optimization of the scheme and mode of operation of the power grid.
• Study of static stability and high-power load nodes.
• Reducing the total power due to the reactive component. As a result, the proportion of active power will increase, which is positively affected by the fight against losses.
• Optimization of the load of transformers.
• Modernization of equipment.
• Various load leveling methods. For example, it can be done by entering a multi-tariff payment system, in which the high-load clock is the increased cost of kW / h. This will significantly consume electricity at certain periods of day, as a result, the actual voltage will not "seem" below the permissible norms.

Reduce commercial costs can be as follows:

• regular search for unauthorized connections;
• creation or expansion of control units;
• testing testimony;
• automation of data collection and processing.

Methodology and an example of calculating electricity losses

In practice, the following techniques are used to determine the loss:

• conducting operational calculations;
• daily criterion;
• calculating medium loads;
• analysis of the largest loss of transmitted power in the context of the day-hours;
• appeal to generalized data.

Full information on each of the above methods can be found in regulatory documents.

At the end, we give an example of calculating costs in the TM 630-6-0.4 power transformer. The formula for calculation and its description are shown below, it is suitable for most types of similar devices.

Calculation of losses in the power transformer

To understand the process, it should be familiar with the main characteristics of TM 630-6-0.4.

Now go to the calculation.

When transmitting electrical energy from power plant generators to the consumer, about 12-18% of all generated electricity is lost in air conductor and cable lines, as well as in windings and steel cores of power transformers.

When designing, it is necessary to strive to reduce the losses of electricity at all parts of the power system, since electricity losses lead to an increase in power plants, which in turn affects the cost of electricity.

In networks up to 10KV power loss are mainly due to heat heating from the current operation.

Power loss in line.

The loss of active power (kW) and the loss of reactive power (KVOM) can be found according to the following formulas:

where I.calculation- the estimated current of this section of the line, and;

R.l. - Active line resistance, Ohm.

Power loss in transformers.

Power loss in power transformers consist of losses that do not depend on the load. The loss of active power (kW) in the transformer can be determined by the following formula:

Losses of active power in the transformer

where ? PST - loss of active power in transformer steel at rated voltage. Depend only on the power of the transformer and the voltage transformer applied to the primary winding. ? PST equate ? PC;

? PC- loss of idling transformer;

? Rob - losses in windings at the rated load of the transformer, kW; ? Rob equate ? RK..

? RK.- short circuit loss;

? \u003d S / Sna - the transformer load coefficient is equal to the ratio of the actual load of the transformer to its nominal power;

Losses of the reactive power of the transformer (KVOM) can be determined by the following formula:

where ? QT - loss of reactive power on magnetization, kvar. ? QT equate ? Qx.

? Qx - the magnetizing power of the idle transformer;

? Qras - Losses of the reactive scattering power in the transformer at rated load.

Values ? PCT ( ? Px) and ? Rob ( ? RK) Drive in catalogs of manufacturers of power transformers. Values ? QT ( ? Qx) and ? Qras Defined according to directories from the following expressions:

where IX - idling current transformer,%;

UK - short circuit voltage,%;

Ine - nominal transformer current, and;

Xtra - reactive resistance of the transformer;

Sna - Rated power of the transformer, kVA.

Loss of electricity.

Based on the loss of power, it is possible to calculate the loss of electricity. Here you should be attentive. It is impossible to calculate the loss of electricity multiplying the power loss with any particular load on the number of hours of the line. This should not be done, because during the day or season, the consumed load changes and so we get unreasonably overestimated value.

Maximum loss time ? - The conditional number of hours during which the maximum current flowing in the line creates energy losses equal to the actual energy loss per year.

Time to use maximum load or maximum use time TMA. Called the conditional number of hours during which the line, working with the maximum load, could transfer so much energy for the year for a year as when working on a valid variable graphics. Let be W.(kW * h) - energy transmitted over a certain period of time, RMA.(kW) -Maximal load, then the time of using maximum load:

TMA \u003d W / RMA

Based on statistical data, the following values \u200b\u200bwere obtained for individual groups of electrical receivers. TMA.:

• For internal lighting - 1500-2000 hours;
• Outdoor lighting - 2000-3000 h;
• Industrial enterprise Singlemen - 2000-2500 h;
• Two-chaired - 3000-4500 h;
• Three-chaired - 3000-7000 h;

Loss time ? can be found on schedule, knowing TMA. and power factor.

Energy loss in the transformer:

Energy loss in the transformer

where ? Waater -Theless loss of active energy (kW * h) in the transformer;

? Wtr. -Theless loss of reactive energy (kvar * h) in the transformer.

Losses in the power grids consider the difference between the transmitted electricity from the manufacturer to the consumer consumed consumed electricity. The losses occur on the power transmission, in power transformers, due to the vortex currents during the consumption of instruments with a reactive load, as well as due to poor insulation of the conductors and theft of unaccounted electricity. In this article, we will try to tell in detail about what electricity losses in electrical networks are, as well as consider events to reduce them.

Distance from power station to supplying organizations

Accounting and payment of all types of losses is regulated by the legislation: "Decision of the Government of the Russian Federation of 27.12.2004 N 861 (Ed. Dated February 27, 2004)" On approval of the rules of non-discriminatory access to services for the transmission of electrical energy and providing these services ... "P. VI. The procedure for determining losses in electrical networks and payment of these losses. If you want to deal with those who need to pay part of the lost energy, we recommend to explore this act.

When transmitting electricity over long distances from the manufacturer to a supplier to the consumer, part of the energy is lost for many reasons, one of which is a voltage consumed by ordinary consumers (it is 220 or 380 V). If we carry out the transportation of such a voltage from power plant generators directly, it is necessary to pave a power grid with a wire diameter that will provide all the necessary current at the specified parameters. Wires will be very thick. They cannot be suspended on the power lines, due to the high weight, the gasket in the ground will also cost anything.

To learn more about whether you can in our article!

To exclude this factor in distribution networks high-voltage lines Power transmission. Simple formula Calculation is as follows: p \u003d i * u. Power is equal to the current to the voltage.

Power consumption, W	Voltage, B.	Talk, A.
100 000	220	454,55
100 000	10 000	10

Increased voltage when transmitting electricity in electrical networks, it is possible to significantly reduce the current, which will allow you to do with wires with a much smaller diameter. The underwater stone of this transformation lies in the fact that there are losses that someone should pay. Transmitting electricity with such voltage, it is significantly lost from poor contact of the conductors, which over time increase their resistance. Losses increase with increasing humidity of air - the leakage current on the insulators increases and the crown. Also increase the losses in cable lines while decreasing wire insulation parameters.

Pass the supplier energy into the supply organization. In turn, there should be parameters to the desired indicators: convert the obtained products to a voltage of 6-10 kV, dilute with cable lines on points, after which it is converted to a voltage of 0.4 kV. Again there are losses for transformation when operating transformers 6-10 kV and 0.4 square meters. The household consumer delivers electricity in the desired voltage - 380 V or 220V. Any transformer has its own efficiency and is designed for a certain load. If the power of consumption is greater or less than the calculated power, the losses in electrical networks increase independently of the desire of the supplier.

The next pitfall pops up inconsistency of the transformer power converting 6-10 kV in 220V. If consumers take energy more transformer passport, it or fails, or it will not be able to provide the necessary parameters at the output. As a result of a reduction in the voltage of the network, the electrical appliances work with a violation of the passport mode and, as a result, increase consumption.

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

Home Conditions

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

It consists of:

1. Losses on when the calculated consumption parameters are exceeded.
2. Bad contact in switching devices (switches, starters, switches, cartridges for lamps, forks, sockets).
3. Capacitive load of load.
4. Inductive load.
5. Use of outdated lighting systems, refrigerators and other old equipment.

Consider events to reduce electricity losses in homes and apartments.

Claim 1 - Fighting this type of loss alone: \u200b\u200bApplying conductors of the appropriate load. In existing networks, it is necessary to monitor the compliance of the parameters of the wires and power consumed. If it is impossible to adjust these parameters and enter to normal, it should be put up with the fact that the energy is lost on the heating of the wires, as a result of which the parameters of their insulation change and the likelihood of a fire occurs in the room. We were told in the relevant article.

Clause 2 - Bad Contact: In the Rugs - this is the use of modern designs with good non-oxidizing contacts. Any oxide increases resistance. In the starters - the same way. Switches - the on-shutdown system should use a metal that is well withstanding moisture, elevated temperatures. Contact must be provided with good pressed one pole to another.

Clause 3, p.4 - reactive load. All electrical appliances that do not belong to the incandescent lamps, the electric stoves of the old sample have a reactive component of electricity consumption. Any inductance when the voltage is applied to it resists current over the current due to the emerging magnetic induction. After a while, electromagnetic induction, which prevented the passage of the current, helps its passage and adds part of the energy to the network, which is harmful to common networks. The so-called vortex currents occur, which distort the true testimony of electric meters and make negative changes to the parameters of the supplied electricity. The same happens at capacitive load. Arriving vortex currents spoil the parameters to the electricity supplied consumer. Fighting - the use of special compensators of reactive energy, depending on the load parameters.

P.5. Use of outdated lighting systems (incandescent bulbs). Their efficiency has the maximum value - 3-5%, and maybe less. The remaining 95% go to heat the filament and as a result of heating ambient And the radiation is not perceived by the human eye. Therefore, to improve this type of lighting has become inappropriate. There are other types of lighting - luminescent lamps that have become widely used lately. The efficiency of luminescent lamps reaches 7%, and LED up to 20%. The use of the latter will give energy savings right now and during operation due to a long service life - up to 50,000 hours (incandescent lamp - 1,000 hours).

Separately, I would like to note that it is possible to reduce the loss of electrical energy in the house using. In addition, as we have already said, electricity is lost in its embezzlement. If you notice that, you need to immediately take appropriate measures. Where to call for help, we told in the relevant article on which they refer!

The above methods for reducing the power of consumption give a reduction in the load on wiring in the house and, as a result, reducing losses in the power grid. As you already understood, the methods of struggle are most widely disclosed for household consumers because not every owner of the apartment or at home knows about possible electricity losses, and supplying organizations in their staff are kept specially trained on this topic of workers who are able to deal with such problems.

The magnitude of the constant loss of electricity in the electrical network elements is

W."=(R K +. R in +. R xx) T. On \u003d. R"T. incl, (8.1)

where T. On - the inclusion time or time of the electrical network elements during the year. For air and cable lines and transformers, when performing project calculations is accepted T. On \u003d 8760 h.

The total magnitude of electricity loss in the network is

W.=W."+W.". (8.2)

Consider ways to determine the variables of losses in the electrical network. Suppose for an electrical network element, such as an aerial line having active resistance R., Known annual load schedule. This graph appears in the form of a step schedule for duration D t. I each load R i. (Fig. 8.1, but).

Energy transmitted during the year through the network element in question, will express as

W.= . (8.3)

This energy is an area of \u200b\u200ba figure limited by a load schedule.

In the same graph, we will construct a rectangle with a height of the greatest load R Max, and an area equal to the area of \u200b\u200bvalid load schedule. The basis of this rectangle will be time T. Max. This time is called the duration of the use of the greatest load. During this time, during the operation of the network element with the highest load through it, the same electricity will be transferred as when working on a valid annual load graph. Average values T. Max for various industries are given in.

Power loss in the network element under consideration for each i.-Ho time interval will be

R i \u003d ( S. I / U. number) 2. R.=(P. I / U. NOM COS) 2 R., (8.4)

where COS is the load power factor.

In fig. 8.1, b. A stepped plot of power loss, built by expression (8.4). The area of \u200b\u200bthis graph is equal to annoying loss of electricity in the network element under consideration

a) b)

Fig. 8.1. Load graphics for time definition

T. Max ( but) and the time MAX ( b.)

W."= . (8.5)

By analogy with Fig. 8.1, but Build a rectangle with a height equal to the greatest loss. R MAX, and an area equal to the area of \u200b\u200bthe actual electricity loss schedule. The basis of this rectangle will be time MAX. This time is called time of the highest power loss. During this time, during the operation of the network element with the highest load loss of electricity in it, it will be the same as when working on a valid annual load graph.

Connection between T. Max and Max approximately established empirical addiction

max \u003d (0,124+ T. Max 10 -4) 2 8760. (8.6)

With promising design of electrical networks, the consumer load schedule is usually not known. With a certain degree of reliability, only the highest settlement load is known. R Max.

For characteristic consumers, the reference literature provides values T. Max. In this case, the variables of the annual loss of electricity in the electrical network element are determined by expression

W."=P. Max Max, (8.7)

where MAX is calculated by expression (8.6).

Control questions To section 8.

1. Explain the terms "constant losses" and "variable loss" electricity.

2. Name the constant loss components.

3. What is the number of hours of using the greatest load?

4. What is the number of times the highest power loss?

5. How variables of energy loss are calculated when designing

electrical networks?