Power supply of Zabrezye settlement

Contents

Contents

1 Introduction

2 Initial data

3 Determination of allowable voltage losses

in electrical networks

4 Calculation of electrical loads

5 Electrical calculation of 0.4 and 10 kV networks

6 Determination of energy losses in electrical networks

7 Design of the line and TC

8 Calculation of short-circuit currents

9 Selection of substation electric sets

10 Protection of 0.4 kV outgoing lines

11 Overvoltage protection

12 Earthing

Conclusion

Literature

Paper

The course project on the topic Power supply of the village of Svilo was completed in the scope: a calculation and explanatory note on 44 pages of printed text, tables - 14, figures - 5, a graphic part on 1 sheet of A1 format and 1 sheet of A3 format.

Keywords: Power supply, electricity consumption, power, power factor, losses, transformer substation, airline.

The purpose of the project was to calculate electrical loads, determine permissible voltage losses, determine the number of TPs, draw up diagrams of 0.4 kV, 10 kV networks, electric calculation of 0.4 kV, 10 kV networks, determine energy losses, design of lines and TPs, calculate short-circuit currents, select substation equipment, protect lines from overvoltage and ground .

The course project is executed in accordance with the "General requirements for the design organization and the rules for issuing diploma and course projects (works)."

Introduction

Currently, a large number of water supply plants, high-performance production units for drying and sorting grain, production lines of workshops and fodder preparation plants, large poultry farms, industrial-type complexes for fattening cattle, pigs, communal facilities, residential buildings and other enterprises are electrified in agricultural production. The agro-industrial complex annually consumes more than 14% of electricity, and according to the nomenclature of electrical equipment used, agriculture occupies one of the first places among the sectors of the national economy of the Republic of Belarus.

Today, all agricultural facilities use electricity, all residential buildings in rural settlements have an electric input. Overhead transmission lines cover all settlements. However, this does not mean that the work on the electrification of agriculture has ended - the electric load in agriculture is constantly increasing, there is a need to reconstruct, expand power lines, introduce the latest equipment to replace the outdated one.

Despite some positive results, the level of agricultural electrification achieved and the volume of electricity consumption does not meet modern requirements. The energy content of labor in agricultural production is much lower than in industry. Therefore, there are quite great prospects for the electrification of agriculture in the future. It is planned to increase the energy supply of agriculture, increase the volume of electricity consumption in agricultural production, as well as its supply to the communal needs of the rural population.

The electricity supply of industrial enterprises and settlements in rural areas has its own characteristics compared to the electricity supply of industrial enterprises and cities. The main features are the need to supply electricity to a huge number of relatively low-power consumers dispersed throughout the territory, low quality of electricity, and high reliability requirements.

Thus, it can be concluded that the problems of electricity supply in agriculture are of great importance. The economic efficiency of the use of electricity in agricultural production depends to a large extent on a rational solution to these problems.

Design of lines and PI

0.4 kV mains shall be three-phase AC with a blind grounded neutral.

During the new construction (reconstruction) of 0.4 kV VL, it is necessary to use HF (isolated air lines) with PIS (self-supporting isolated wire) without a separate carrier element in accordance with the requirements of TAP 339.

Designed VLI0.4 kV are adopted on the basis of reinforced concrete posts SV 952V and SV 1101a with wires with insulation from cross-linked polyethylene and a distance between supports of not more than 50 m.

The length of the air branch to the inlet shall be not more than 25 m. If the distance of the main line or linear branch of the ERI to the building exceeds 25 m, additional supports shall be installed.

The number, grade and sections of wires on the designed VVI0.4 kV are selected according to permissible current loads, checked for voltage loss at the end of the lines, as well as for providing automatic shutdown in case of short circuits.

To ensure normalized street lighting, the project provides for installation of outdoor lighting fixtures of ZhKU51 type with sodium lamps with a capacity of 70 W on the designed VLI0.4 kV supports.

Routes of designed VLI0.4 kV are made on the basis of topography. Arrangement of support on routes VLI0.4 of kV is given in drawings of a graphic part of the project.

VL routes are laid on two sides of the streets. It is allowed to pass on one side, provided that interference with traffic and pedestrians is excluded, as well as the convenience of branching from the VL to entrances to buildings and a reduction in the number of intersections with engineering structures.

On VLI0.4 kV route we install the following types of supports:

Single chain reinforced concrete supports:

- intermediate P1k - 9 pcs;

- complex O1k - 17 pcs;

- terminal K1k - 10 pcs;

The PIS attachment, connection (self-supporting insulated wire) and connection to the PIS shall be as follows:

1) fixation on intermediate, angular intermediate, cross and additional supports of VLI - by means of supporting clamps behind the bearing element.

PIS without a separate load-bearing element in the presence of auxiliary strands is attached in support clamps for the whole twisted bundle.

The supporting clamp shall be constructed using materials that prevent damage (abrasion) to the insulation of the PIS;

2) attachment on anchor-type VLI supports, as well as end attachment of branch wires on the support and on the input - using tension clamps for the bearing element, namely for the main cores of the PIS without a separate bearing element - (phase + "0"). Auxiliary cores (if any) are laid along the clamp.

Tensioning clamp for PIS attachment without a separate bearing element behind the main insulated cores shall be designed to prevent destruction of the insulation layer of wires;

3) connection of the main and auxiliary (external lighting) cores of the PIS - using pressed insulated sealed connecting clamps-sleeves (hereinafter - insulated connecting clamps-sleeves).

Connection of PIS main cores without separate bearing element having mechanical load shall be performed with the help of insulated connecting clamps with permissible mechanical strength of at least 80% of wire breaking force.

Connection of insulated PIS cores by means of pressed insulated coupling clamps-sleeves shall be carried out using a specially designed tool (recommended by the clamp manufacturer);

4) it is recommended to perform no more than one PIS connection in the IDL anchor span;

5) connection of wires in the branch span to the input is not allowed;

6) connection of grounding conductors is made by means of spot clamps;

7) connection to the PIS (branch from the PIS) is carried out using branch terminals.

Branch from insulated cores of PIS (main, auxiliary, insulated zero carrier) is performed by means of piercing clamps.

It is recommended to use tight and moisture-proof branch piercing clamps. Otvetvitelny clips it is necessary to connect branch wires from the VL to input to input wires and also to connect lamps, the equipment, devices of control of tension, grounding devices.

The distance between adjacent sealed (moisture-proof) clamps of different PIS phases shall be at least 5 cm;

8) bolted connections of linear reinforcement (except for branch clamps with breaking element) shall be tightened with the force specified by the specification or other TNAP.

Support and tensioning clamps shall be attached to VLI supports, building walls and structures using hooks, brackets and attachment units.

Tensioner elbows UN2 installed on each rack SV952v are used to tighten the wires.

Clamps for K-NM-1 grade line are used for attachment on anchor and corner anchor supports, as well as for maintenance of bundle of self-carrying insulated wires in tensioned condition.

To perform branching of VLI wires at removal of insulation at the point of connection, use branch clamp ZVA01. Nominal section of wires connected in the clamp is 16-120 mm2.

Tensioning clamp ZP02 is used for insulated two-wire branch from VLI to entry into buildings and structures, attachment of insulated wires to VLI supports and building walls.

To prevent the impact of climatic factors on the contact connections, we use the protective box KZ01 (complete to the terminal ZVAL01).

TC are used to receive electric energy of three-phase alternating current with frequency of 50 Hz with voltage of 10 kV and conversion to electric power with voltage of 0.4 kV. TP 10/0.4 kV are designed for power supply to consumers of small capacity in rural areas.

The substation equipment shall be installed on steel structures fixed on the rack:

- power transformer;

- 10 kV power fuses;

- overvoltage limiters 10 kV (or arresters);

- pin insulators 10 kV;

- low-voltage shield;

- 0.4 kV pin insulators.

The 10 kV disconnector is installed separately on one of the 10 kV VL supports.

The main solution of the column TC provides for the connection of 0.4 kV lines made by isolated self-carrying wires.

On the 0.4 kV side, three (two) lines and a street lighting feeder are connected to the prefabricated buses. Circuit breakers are installed in 0.4 kV circuits. Fuses, contactor and photorelle (for automatic control) are installed in street lighting feeder circuits.

Power at 0.4 kV input is accounted for by a three-phase meter connected through current transformers.

For the operation of the meter in winter, a heating device is provided using resistors that ensure normal operation at ambient air temperature up to - 45 ° С.

To connect street lighting fixtures, we provide a separate outdoor lighting cabinet (SHN), in which there are installed: a switch and fuses, if necessary, a counter and a photoautomatics device.

For stationary performance of grounding of VLI0.4 of kV at the beginning and at the end of each highway, long linear branches, installation sites of the partitioning points we provide grounding devices

Overvoltage protection and grounding

Protection of the equipment of substations against retension is carried out by valve RVP10 rated sportsmen from the highest tension and PBH0.5 type from 0.4 kV.

Currently it is recommended to use overvoltage limiters.

If there are cable inserts up to 100 meters long in networks of 10 kV and higher (leads to the substation, passages under the responsible highways and railways, etc.), one set of arresters is installed either on the buses of the substation or on the support, where the overhead line goes into cable .

If the substation has multiple cable leads, then a set of arresters is installed at each input. Moreover, with an input length of more than 100 m, they are installed on the buses of a consumer substation having a general energy accounting

Conclusion

During the course work, the 0.4 kV overhead line was reconstructed in order to reduce losses in the transmission of electricity over the distance, save material resources during construction and increase the efficiency and quality of electricity supply. The work includes items that have been fully implemented: justification of the project theme, characteristics of the design object, calculation and selection of electrical loads, selection of TP10/0.4 kV quantity and installation place, electrical calculation of line 0,4/0.23 kV, calculation diagrams, determination of design capacities in line sections, selection of section area and number of wires, determination of voltage losses, calculation of external lighting wires, power selection of transformers, check of low-voltage network for possibility of electric motor starting, design of 0.4/0.23 kV network, calculation of short-circuit currents, selection of protection of outgoing lines and FTP equipment.