Reconstruction of 10 kV KL with improved reliability

Contents

Project Documentation Package List

Diploma Design Assignment

Introduction

1. Source Data

1.1. Production characteristic of the object

1.2. General characteristics and civil parameters of KL-10 kV electrical network. Justification of the need for its reconstruction

1.3. Characteristics of electrical equipment placement

2. General Electrical Part

2.1. Parameters of engineering support systems of the agricultural air base "Dolgopolie" in the village of Dolgopolie, Vitebsk region

2.2. Calculation of electrical loads (taking into account development prospects)

2.3. Determination of allowable voltage losses in 0.4 kV network

2.4. Selection of power and number of substation transformers

2.5. Calculating Cable Section and Selecting Cable Tags

2.6. Description of construction and reconstruction technologies KL10 kV

2.7. Calculation of short-circuit currents

2.8. Selection of main equipment of transformer substations

3. Special part

3.1. Development of technical means of reliability improvement

elektrobzheniye

4. Safety of life

4.1. Analysis of the state of labor protection in Vitebsk RES

4.2. Development of safety measures during KL10kV reconstruction

4.3. Provision of fire safety during KL10kV reconstruction

5. Economic part

5.1. Essence, relevance and novelty of development

5.2. Selection of technical solutions

5.3. Natural technical and economic indicators

5.4. Capital investments

5.5. Annual operating costs

5.6. Determination of damage from power supply interruption

5.7. Cost of power transmission

5.8. Project Investment Performance Indicators

Conclusion

Literature

Paper

The diploma project was completed to the extent: calculation and explanatory note on 111 pages, tables - 19, figures - 10; The graphic part is on 8 sheets of A1 format.

Keywords: reconstruction of 10 kV network, cable line, increase of reliability of power supply, transformer substation.

The project provides information on the development of the agricultural energy system of the Republic of Belarus and substantiates the need to reconstruct the 10 kV network to increase the reliability of electricity supply to agricultural consumers.

Reconstruction of KL10 network of kV is carried out by design of cable networks of 10 kV and installation of the second transformer substation of 10/0.4 kV. At the first stage, the reconstruction of the 10 kV cable line from TsRP2 to TP17 and the reconstruction of TP17 are provided, and at the second stage, the design of a new 10 kV cable line from TP17 to TP18 is provided. The issues of safety and environmental friendliness of the project, as well as the economic justification of the decisions taken, are considered.

Introduction

Electrification of all sectors of the national economy and life of the population of the Republic of Belarus is one of the most important factors of technological progress. Mass electrification of agriculture in the Republic of Belarus began in the 1950s, just when a significant increase in the capacity of the energy system of the Republic of Belarus became noticeable. It was after this that a government decision was made to join agricultural consumers to the state energy system.

Electrification, that is, the production, distribution of electricity in all sectors of the national economy and household is one of the factors of technological progress. Currently, electricity is the main base of production, animal husbandry, crop production, repair production, stationary processes of crop production. The level of energy security of labor, in these sectors, determines the growth of labor productivity.

The development of the material and technical base of society takes place, first of all, on the basis of accelerating scientific and technological progress, widespread use of discoveries and inventions, achievements in science and technology of electrification and automation of technological processes.

In this regard, reconstruction of already built complexes is being carried out, which with new technologies are able to increase meat production in existing areas. New technologies also help save feed spent on cattle feeding. The share of beef produced by all categories of farms in Belarus is more than 50% in the total meat balance in the live mass.

Currently, it is inconceivable to solve the issues of the development of the economy of the Republic of Belarus, the life of the urban and rural population without reliable and high-quality electricity supply to consumers.

The most important indicator of the power supply system is the reliability of electricity supply. In this regard, the main tasks of rural electricity supply are:

- Improving the quality of electricity;

- ensuring reliability of power supply;

- reduction of electric power losses and its rational use.

According to the Belenergo concern, the maximum electricity consumption in the Republic of Belarus was recorded in 1991 and amounted to 49.2 billion kWh, and in 1998 - 30.5 billion kWh. According to the structure of electricity consumption, agricultural production consumers make up 9.1%, rural population - 4.8%, urban population - 14%. Also, according to the Belenergo concern, per capita electricity consumption in the Republic of Belarus in 1997 is 3275 kWh/year, with a population of 10.23 million people.

1. source data

1.1 Production characteristics of the facility.

The reconstructed KL10kV network is located in the village of Dolgopolie, Vitebsk region and is located on the territory of control of the Vitebsk RES. Consumers are the Dolgopolie agricultural air base and the village of Dolgopolie.

The most common method of controlling pests and diseases of crops is spraying with toxic chemicals. The greatest effect of protective measures is given when they are carried out as soon as possible - within three, a maximum of five days, which can not always be provided by ground-based methods of introducing plant protection. In many cases, small aviation can come to the aid of such farms. Light aircraft are 10 times more productive. Aviation remains indispensable in the control of especially dangerous pests - Colorado beetle, locust and meadow moth, when fast processing of huge areas is required. Small aviation improves the quality of the crop with the help of late feeding, without damaging the plants. Aircraft do their job even when ground equipment cannot enter the field due to high soil moisture. The aircraft can work in small fields or sections of unpaved roads measuring 50 meters. No special loading area is required for chemical filling facilities. Aviation costs twice as much, it is possible to demolish the drug to neighboring crops, there is a ban on some pesticides for aircraft processing, in addition, aviation is dependent on weather conditions. But there are huge advantages. This is a high processing speed, no losses due to damage to crops by wheels of equipment (up to 4%), the possibility of applying fertilizers in the early spring and late autumn period (in rasputz) and at the late stages of plant development.

1.2 General characteristic and general construction parameters of an electrical network KL10 of kV. Substantiation of the need for its reconstruction.

As a result of engineering and geological surveys, the following engineering and geological elements were identified in the section of the reconstructed network of lines

EGE - 1 - asphalt concrete ShMW II/60

EGE - 2 - Dolomite crushed stone GOST 8267-93

EGE - 3 - compacted soil, filling age more than 10 years.

EGE - 4 - medium-density sand, with gravel and pebbles up to 15%.

Groundwater is opened by drilling wells at a depth of 1.5-2 m.

During works and calculations on the reconstruction of the KL10 kV network in Dolgopolie in accordance with the survey materials, SNiP 2.01.0785 "Loads and Impacts" and PUE85 the following initial data were adopted:

1) seismicity of the item (in points according to the scale GOST 624952) - up to 6 points;

standard high-speed maximum wind head at an altitude of 16 m;

the average height of snow cover in unprotected areas is 12 cm (highest - 20 cm);

ice wall thickness at a height of 10 m above the ground surface with repeatability once every 10 years for the II ice region - 10 mm;

5) normative depth of ground freezing - 0.8 m;

6) average temperature of the coldest five days 28 С;

7) weight of snow cover for the I region - 0.5kPa;

8) base soils:

- asphalt

- medium-sized sand with gravel and pebbles

- middle-lying peat

The reconstruction of the KL10kV network of the Dolgopolie air base is envisaged due to the increase in loads due to an increase in the number of equipment used and the connection of new facilities. As a result of the appearance of consumers of the second category, it became necessary to develop means to improve the reliability of power supply.

Currently, the Dolgopolie air base is powered by the existing TP17, which, in turn, is powered by a cable line from the TsRP2. The transformer substation, previously intended for power supply to the Dolgopolie air base, as well as the nearby village of Dolgopolie, will become a source of electricity directly for the village. Taking into account the growing power consumption and the presence of consumers of the second category, it was decided to reconstruct the KL10 kV network and develop/install another transformer substation in order to provide a power reserve and increase the reliability of the power supply. The new transformer substation TP18 will be a source of electricity for the Dolgopolie air base. In this way we get 2 transformer substations for 2 of our consumers.

The design provides for the laying of two 10 kV cable lines from TP17 for power supply to the designed transformer substation TP18 and the reconstruction of the cable line instead of the old one from TP2 to the existing TP17. 10 kV power supply networks are made by cables with aluminium cores of AABl grade with a section of 70mm2. 10 kV power cables are laid in the ground in the trench at a depth of 0.7 m from the layout marks and in the designed cable passage through the existing taxiway. When crossing with utility networks and driveways, cables are laid in polyethylene pipes ∅ 160. Cables along the entire length are covered with brick.

1.3 Characteristics of electrical equipment arrangement.

When laying cable lines directly in the ground, cables must be laid in trenches and have a backfill from below, and backfill with a layer of shallow land that does not contain stones, construction debris and slag.

Cables throughout shall be protected against mechanical damage by coating at voltage of 35 kV and above with reinforced concrete slabs not less than 50 mm thick; at a voltage below 35 kV - slabs or clay ordinary brick in one layer across the cable route; when digging a trench with an earth-moving mechanism with a cutter width of less than 250 mm, as well as for one cable - along the route of the cable line. The use of silicate, as well as clay hollow or hole bricks is not allowed.

The depth of cable lines laying from the layout elevation must be at least: lines up to 20 kV 0.7 m; 35 kV 1 m; at the intersection of streets and squares, regardless of the stress of 1 m.

When laying at a depth of 11.2 m, cables of 20 kV and below (except for cables of city power grids) can not be protected from mechanical damage. The signal tape shall be placed in a trench above the cables at a distance of 250 mm from their outer covers. When one cable is placed in the trench, the tape must be laid along the cable axis, with more cables, the edges of the tape must protrude beyond the extreme cables by at least 50 mm. When laying more than one tape across the width of the trench, adjacent tapes must be laid with an overlapping width of at least 50 mm.

When using signal tape, cables shall be laid in a trench with a cable cushion device, the cables shall be filled with the first layer of earth and the tape shall be laid, including the tape being filled with a layer of earth along the entire length, in the presence of a representative of the electrical installation organization and the owner of the electrical networks.

The design provides for the reconstruction of TP17, which includes the replacement of equipment RU0.4kV and RU10 kV. In RU10 of kV cells with vacuum KSV switches are established, in RU0.4 of kV ShchO70 panels are installed. Previously, TP17 was a source of electricity for both the air base and the nearby village of Dolgopolie and its consumers. The project provides for the construction of another transformer substation (TP18), which will power the consumers of the nearby village from the existing TP, and the new TP18 will be a source of electricity directly for the needs of the air base. Existing power transformers in TP17 (2x250kVA) are not subject to replacement according to economic calculations, presented loads of existing TP17 consumers and projected loads of the village taking into account development prospects (Rp.sum. = 215kVA). Installation of electric power metering devices is provided in RU0.4kV TP-17 on inlet automata (2 pcs.) and on outgoing cable lines (2 pcs.).

The design provides TP18 binding with 10/0.4kV cable glands with a capacity of 2x250kVA using quick-mount structures according to the typical design 1.87.97tm.

Transformer substation TP18 is designed for power supply to specialized air transport service facilities (i.e. agricultural air base Dolgopolie). 10 kV line entries - cable. Number of 10 kV cable entries - 2. The transformer substation has one unified construction volume, which allows by replacing transformers and switchboards RU0.410kV during operation to set the optimal capacity without reconstruction of the construction part. The designed transformer substation is accepted taking into account the prospective development.

The voltage of 10 kV for TC is taken as a single system, partitioned into two sections by two disconnectors, on which two 10kV lines and 0.4kV lines are connected. Power transformers are accepted with a capacity of 250 kVA. Grounding of each section of busbars is provided by stationary grounding knives installed in the section chamber.

At a voltage of 0.4kV, a single system of busbars partitioned into two sections by an automatic machine is adopted. The bus section is powered by power transformers connected to the 0.4 kV board through circuit breakers and circuit breakers .

The section of the busbars of the 0.4kV board is accepted taking into account the overload capacity of transformers, in accordance with GOST 1420985, as well as with a test for dynamic and thermal stability at a three-phase short circuit. The single-row location of cameras in RU10kV and two-row location of panels in RU0.4kV is accepted. RU10kV it is completed with cameras of unilateral service of the KSV series.

RU0.4kV it is completed with ShchO70 distribution panels. Also in this room, a combined WC cabinet with ATS and floodlight masts control cabinets are installed. Installation of equipment and structures is carried out by attachment to embedded parts provided by the architectural and construction part of the project .

The earthing device of the transformer substation is common for 10 kV and 0.4 kV. Lightning protection is carried out by rod lightning receptors connected to the TP grounding circuit.

The project provides for the arrangement of access to substations and on-site roads, providing access to the building and structures with asphalt concrete pavement. Ground cable channels are provided from prefabricated reinforced concrete trays laid over the planned territory of the substation on prefabricated reinforced concrete bars on ground packed with crushed stone 100 mm thick. Channels are covered with removable reinforced concrete slabs.

After completion of installation works, reinforced concrete structures are painted with acrylic paints, and metal structures are coated with PF170 varnish for two times according to GF021 primer as per SNiP 2.03.1185 (coating group 1 ).

Special part

3.1 Development of technical means of reliability improvement

power supply

3.1.1 Automatic switching on of reserve

In rural power plants, as in any branch of technology, there are operations that a person cannot perform due to his physical capabilities: rapid response, accuracy and strict sequence of operations or their combination in a short period of time, replacement of human functions due to labour intensity of production, facilitates human work or replaces a person completely, reduces the number of accidents caused by service personnel, improves the reliability of electricity supply to agricultural consumers. Naturally, automation requires additional material investments, but the effect of its implementation in a short time pays off these costs.

In the power supply system, there are a number of automatic devices that help a person solve the above tasks.

Rural electric networks mainly operate in open mode. They are radial and provide one-way power to consumers. This makes it possible to build them more economical, since relay protection is simplified, cheaper equipment is used, technical issues are positively solved to reduce power losses in electrical networks, maintain the required voltage levels at substations, and reduce short-circuit currents. However, the reliability of power supply to consumers in such networks is significantly lower than with double-sided power supply. You can improve the reliability of power supply to consumers in one-way power networks by using the ATS device. It allows you to switch consumers to a serviceable power supply, standby, if the main power supply is damaged. In rural electrical networks, ATS is used at double-transformer substations 35110/10 kV, at substations 10/0.4 kV, on lines 0.38kV and at standby power plants. For example, at a two-transformer substation, when one transformer of the ATS device fails, it provides switching on the sectional switch and connecting consumers powered from the damaged transformer to the bus section of the second transformer.

5. economic part

5.1 Essence, relevance and novelty of development.

This diploma project considered the reconstruction of the KL10 kV network, including the reconstruction of the 10/0.4 kV transformer substation TP17 and the construction of a new transformer substation TP18.

Over time, it is necessary to replace obsolete equipment with modern one, characterized by greater reliability, longer service life and lower volume costs. The reason for the failure in power supply of the agricultural air base Dolgopolie may be technically obsolete electrical equipment TP17. After the reconstruction, the installed capacity of the substation will not change, but its reliability will increase significantly, and the cost of maintaining the facility will be reduced. Upon completion of reconstruction and technical re-equipment, TP17 will fully meet the requirements for new generation substations. This reconstruction of the substation makes it possible to increase the reliability of power supply and the quality of electricity for consumers, as well as reduce power losses and, as a result, operation costs.

Techno-economic calculations allow you to choose the most economical option as a result of comparing two technically acceptable and giving the same energy effect options by their most important indicator: capital investment and annual costs. Variants are compared by total total discounted costs.

Due to the increase in loads, we will consider two options for reconstruction .

5.2 Selection of technical solutions

Taking into account the technical requirements for consideration, accept two options for reconstruction of the existing transformer substation TP17:

1 variant - installation of a new 400 kVA transformer.

2 option - use of two existing transformers with a capacity of 250 kVA

Conclusion

The implementation of the main task for the electric power industry to ensure reliable and high-quality supply of electric energy to the consumer is currently not possible without the introduction of progressive and rational solutions in the field of electrical equipment. This is particularly significant at the planning and development stage of the project documentation.

In this project, the issues of the existing state of the KL10 kV network, operation modes of the main electrical equipment were considered; load calculation, selection of layout and main equipment of substations. To realize the main purpose - to improve the substation operation reliability, the following is adopted:

- reconstruction of existing transformer substation TP17 and design of new transformer substation TP18.

- reconstruction of the cable line from TsRP2 to TP17 and construction of the new cable line from TP17 to TP18.

- calculation and selection of switching equipment satisfying the operating conditions in both normal and emergency modes - 10 kV switches, 10 kV sectional switches, vacuum switches, current and voltage measuring transformers:

- calculation of protection setpoints was made.

- calculation of outdoor lighting of the substation of the agricultural air base Dolgopolie and street lighting of the village Dolgopolie.

- in the occupational safety section, the issues of occupational safety in the Vitebsk electric networks were considered, an instruction on occupational safety and fire safety was developed.

In the economic part of the project, calculations of technical and economic indicators of the project effectiveness were made, in which the choice of technical solutions was considered .

All calculations were made in accordance with the current regulatory requirements and methods, so the proposed reconstruction solutions will achieve the proper level of reliability and efficiency of energy production.