Reconstruction of 110/10 kV substation Yurkovichi Logoysky RES with the development of automation schemes. 110/10kV substation

Contents

Introduction

1. GENERAL PART

1.1. General characteristics of the substation and justification of the need for reconstruction

1.2.Selecting Substation Main Diagram Configuration

1.3. Determination of design load on substation tyres. Selection of number and power of transformers

1.4. Power selection of auxiliary transformer

1.5. Calculation of short-circuit currents on substation buses

1.6. Selection of main equipment of 110 kV switchgear

1.7. Selection of RP main equipment 10 kV

1.8. Selection of 110 and 10 kV buses

1.8.1. Selection of 10 kV buses

1.8.2. Selection of 110 kV buses

1.9. Selection of voltage control devices

1.10. Selection of reactive power compensation devices

1.11. Substation relay protection

1.11.1. Differential protection

1.11.2.MTZ on the 10 kV side

1.11.3.MTZ of outgoing lines

1.11.4. Gas protection

1.11.5. Overload protection

1.11.6. Coordination of protections

1.12. Protection of substation equipment against atmospheric overvoltage

1.13. Energy efficiency and management measures

1.14. Measures for operation of substation electrical equipment

2. SPECIAL PART

2.1. Rationale for the topic. Substation Automation System Requirements

2.2. Automatic switching on of reserve

2.2.1. Purpose and scope of ALT

2.2.2. Requirements to ALT diagrams

2.2.3. Proposed ALT scheme for consumers of Logoy TMO and Epos plant

2.3. Automatically re-enable

2.3.1. Purpose and Scope of the AFA

2.3.2. Requirements for VAS diagrams, classification of VAS diagrams

2.3.3. Development of 10 kV outgoing line APV diagrams

2.4. Development of control diagram of the LDP device on power transformers

3. SAFETY OF LIFE

3.1. Substation Electrical Installation Safety Requirements

3.2. Safety requirements during operation of substation electrical equipment

3.3. Calculation of substation grounding loop

3.4. Safety of life in environmental emergencies

4.ECONOMIC PART

4.1. Comparison of transformer installation options of different capacities

4.2. Determination of maximum load usage time and maximum loss time

4.3. Determination of annual electric power losses in transformers

4.4. Determination of total discounted costs

Literature

Summary

The diploma project was completed to the extent: calculation and explanatory note on 110 pages, tables - 14, graphs - 1, figures - 5; graphic part - on 8 sheets, A1 format.

Keywords: reconstruction; substation transformers; switchgear; electrical equipment; automation diagram.

The project gives a brief description of the 110/10 kV Yurkovichi PS and the need for its reconstruction is justified; electrical equipment of 110 and 10 kV switchgear is selected; selecting a voltage control device and reactive power compensation; substation relay protection schemes have been developed; proposed is a set of measures for power saving and operation of substation electrical equipment.

In a special part of the project, substation automation schemes have been developed, including ATS, APV and RTD.

The project also proposes safety measures during installation and maintenance of electrical equipment of the substation, environmental safety.

In the economic part of the project, the feasibility of installing an additional transformer at the Yurkovichi substation is justified.

Introduction

The Belarusian electric power system was formed as part of the unified electric power system of the former USSR. The Belarusian electricity industry is now a combined energy system, a highly automated complex that is constantly developing, has a common operating mode, a single centralized control room and automatic control.

Mass electrification of agriculture began in the 1950s, when the capacity of the republic's energy system increased significantly and a decision was made to join agricultural consumers to the state energy system. And by the end of 1970, the complete electrification of agriculture in Belarus was completed. Electrification today is the basis for mechanization and automation of production processes, it plays a special role in creating comfortable social and living conditions for the rural population.

At the beginning of 2002, the Belarusian power system had 23 power plants with a total installed capacity of 7,624 MW.

The main tasks of rural electricity supply were currently:

- increase of power supply reliability; improving the quality of electricity;

- reduction of power losses, and its rational use.

The operation of electrical installations should be organized so that all consumers are provided with an adequate amount of high-quality and cheaper electricity.

Based on this, the main tasks of operation are electrically: the units are:

1) development and implementation of measures to reduce the accident rate of rural electric networks;

2) execution of the power generation plan;

3) ensuring high quality of electricity (given voltage and frequency);

4) restoration and reconstruction of distribution networks;

5) introduction of technical means to increase the power factor and reduce power losses;

6) creation of an integrated system of automated control, accounting for the management of electric consumption of agricultural enterprises.

7) implementation of measures to save energy resources. To perform these tasks, the operating personnel shall:

1) accurately observe the specified operating modes of the units;

2) carefully monitor the operation of all parts of the plants, timely detect all abnormalities in the operation and defects of the equipment, taking measures to eliminate them as soon as possible;

3) carefully monitor the quality of electricity (voltage and frequency);

4) properly perform all operations with electrical equipment, strictly observing all operational and job descriptions, rules of technical operation of power plant and networks, safety rules;

5) in due time and carefully to examine, check, tests and repair of electric equipment, revealing and eliminating at the same time all defects able to cause damage of the equipment and accident;

6) to reduce energy consumption for their own needs;

7) to reduce energy losses in networks and transformers;

8) increase the use of equipment by reducing the time of its downtime in repairs, etc.

It was essential to reduce the number of staff by making better use of them and making better use of them.

Every operator must bear in mind that the above-mentioned basic tasks can be carried out only with full observance of production discipline, maintaining exemplary order and cleanliness at the plant, with properly organized work, as well as with systematic improvement of their production skills.

Thus, the strategic goal of the development of agricultural energy is to ensure reliable, economical and sustainable energy supply to consumers while reducing the energy intensity of agricultural production, and therefore its cost.

1.1. General description of substation and justification of reconstruction

The existing Yurkovichi substation is located in the North-Western part of Logoisk. This substation is intended for power supply to city consumers in Logoisk, the main of which are the Epos plant, bakery, creamery, TMO, as well as agricultural consumers of the Logoisk district. The Yurkovichi substation receives power by branch from VL 110kV Pleshchenitsa - Khotenovo.

The most important consumer of the substation is the Epos plant. Historically, the plant's equipment and internal distribution networks were connected to the switchgear (RP) of its own power plant with a nominal voltage of 6kV generators.

In the late 40s and 50s, when the power of the power system increased and significantly exceeded the pre-war level due to reconstruction, after the restoration of power plants destroyed during the war in the regional and other cities of the republic, as well as with the commissioning of large (Svetlogorsk, Berezovskaya and Lukomlskaya) power plants, it became possible to join agricultural, communal and other consumers to the state power system.

During these years, a 110/6kV substation (PS), called Yurkovichi, was built to power consumers of the Epos plant and include it in a single power plant system.

A technical survey showed that there was no redundancy at this substation, the equipment was outdated, the power of one transformer was not enough to provide reliable electricity to consumers.

In order to increase the capacity of the distribution network, in connection with the connection of new capacities, as well as consumers of the first category (primarily the bakery, the Epos plant, the creamery, TMO, etc.), the need for the reconstruction of the substation is ripe .

For this purpose, a second 110/10kV transformer, as well as devices for automatic switching on the reserve (ATS), and automatic switching on (ATS) are provided at the substation.

1.2. Selecting the Main Substation Diagram Configuration

The main electrical connection diagram of the existing part of the substation is shown on sheet 1 of the graphic part of the project.

In it, on the high voltage (HV) side, a 110 kV high-frequency communication unit, a disconnector, a short-circuit breaker and dischargers are installed. For the earthing of the transformer neutral, a single-phase earthing device of an external installation with a set of dischargers is provided.

The power transformer of the TMN type - 6300/110 with a capacity of 6300 kVA on the high voltage side has built-in current transformers TVT - 110/300. On the side of the lower voltage of 6 kV RP - 6 kV there are 11 rolled-out cells of the K-37 series:

- input cell;

- auxiliary transformer cell;

- fuse and arrester cell;

- cell of voltage measuring transformers;

- communication cell with RP - 6 kV of the power plant ;

- six cells of outgoing lines for power supply to consumers of the plant.

Cells of input 10 kV and outgoing lines are equipped with oil switches of VMPP - 10 on 630 A type with built-in spring actuators for 220 V AC voltage.

The part of the substation to be reconstructed is shown on sheet 1 of the graphic part of the project. Expansion is provided using the standard HTC-110/10 scheme.

As a result of the reconstruction, the TMN 2500/110 transformer is additionally installed on the PS, as well as on the 110 kV side of the higher voltage, a linear disconnector, a separator, a short-circuit and a neutral earthing electrode of the transformer are additionally installed.

On the side of the low voltage (LV) of the 10 kV thrust reverser, cells of the K-47 series with rolled-out switches of the VK-10 type are equipped:

- 10 kV input cell;

- cell of voltage measuring transformer;

- auxiliary transformer cell (TSN);

- 10 kV switchgear communication cell with power plant;

- five cells of 10 kV outgoing lines to feed adjacent agricultural and other consumers.

1.13. Energy efficiency and management measures

Improving the efficiency of electricity supply to agriculture is a big complex task. In essence, the tasks of improving the quality of electricity and the reliability of power supply are closely related to it. Therefore, in most cases, the activities described above simultaneously address the problem of improving the efficiency of electricity supply. Measures to reduce the loss of electricity and its rational use are very important for its solution.

All electrical installations that make up the power supply system, including electrical lines and transformers, have active resistances. Therefore, when transmitting, distributing and converting electric energy, it is lost.

Electric lines and transformers account for the vast majority of energy losses in rural networks, and usually only losses in these electrical installations are taken into account in practical calculations. Energy losses in wires, ka-whites and transformers windings are proportional to the square of the load current flowing along them, and therefore they are called load losses. The load current typically varies over time, and the load loss is often referred to as variable.

As loads grow and new consumers are connected to the electric network, electrical energy losses increase in it. Power and energy losses are systematically calculated at the electric network enterprises, and on the basis of these calculations, where necessary, measures are taken to reduce losses.

There are organizational measures to reduce losses, measures to improve electricity metering systems, as well as technical measures.

The main organizational activities include:

1) selection of optimal open points of overhead lines (VL) with voltage of 10... 35 kV with two-way power;

2) maintaining optimal voltage levels on 10 kV buses of district transformer substations (RTP) 110... 35/10 kV and 0.38 kV TP 10/0.38 kV tyres;

3) disconnection of one of transformers in low load modes at two-transformer substations, as well as disconnection of transformers at substations with seasonal load;

4) alignment of phase loads in 0.38 kV networks;

5) reduction of repair and maintenance time of lines, transformers and switchgears;

6) reduction of energy consumption for own needs of substations.

Organizational arrangements, as well as improvements to electricity metering systems, generally do not require significant initial costs and therefore are always appropriate.

This is not the case with technical activities related to additional capital investments.

The main technical measures in rural electric networks include:

1) installation in networks of static capacitors, including batteries with automatic power control;

2) installation on RTP 110... 35/10 kV load-controlled transformers (RTD);

3) replacement of underloaded and overloaded transformers on consumer TPs;

4) increase of network capacity by construction of new lines and substations;

5) replacement of wires on overloaded lines, including replacement of from-branches from VL with voltage of 0.38 kV to buildings;

6) switching of electric networks to higher rated voltage.

The most effective of these measures is the compensation of reactive power, primarily using static capacitors.

The principle of reactive power compensation in parallel with the connected capacitors is as follows.

Part of the power transmitted over the line, namely reactive, is not spent on heat or mechanical work, but is only a measure of the energy exchanged between the magnetic fields of the source and the receiver. However, the current corresponding to the reactive power flowing through the transmission line causes a loss of power and voltage in it.

The reactive current and therefore the line current can be reduced by connecting a capacitance C in parallel to the receiver, in which current Ic directed opposite to current IL will flow. Then a smaller total current will flow in the line.

At the same time, the angle between voltage and current will decrease from A to A, the power coefficient will increase from A to A, the reactive power coefficient will decrease from A to A and the power losses and voltages will also decrease.

To ensure the highest economic efficiency, the power of capacitor batteries in networks with a voltage of 0.38 kV must be selected so that during the hours of maximum reactive load, the power factor for consumers is at least 0.95. In this case, the reactive power coefficient tgetashould not exceed 0.33.

Installation at substations 110... 35/10 kV transformers with RTD are necessary not only to reduce energy losses, but primarily to comply with standard voltage deviations in consumers.

Due to the mismatch of actual and design loads, some transformers of the network in operation may not be loaded, and in subsequent years the increase in the load of part of these transformers is unlikely. In this case, it is advisable to replace the transformer with an apparatus of lower power. When replacing, idling losses are reduced, but losses in the transformer windings are increased. Taking this into account, it is possible to determine the maximum load of the installed transformer, at which it is advisable to replace with a transformer of lower power.

The increase in network capacity through the construction of new lines and substations, as well as the replacement of wires on congested lines, is usually carried out during the development of the network according to special projects.

With regard to the conversion of electric networks to a higher rated voltage, for rural networks, it is practically possible to only transfer the 6 kV networks preserved in certain areas to 10 kV.

The rational use of electricity involves primarily improving the operation of its receivers. At the same time, technical and economic calculations should be carried out for the entire power supply system, that is, its production, distribution and use. The economic effect should be determined on the scale of the entire energy system, but not on a separate farm.

For the rational use of electricity, it is important to rationalize its consumption, that is, to establish standards of specific consumption. In the presence of scientifically sound, progressive standards and an appropriate system of material remuneration for their implementation and overfulfilling, significant energy savings are provided.

As the technological process changes, personnel development, installation of improved equipment, the norms should be systematically revised; this is the responsibility of the employees of the electrical service of the economy.

The calculated specific power consumption rates must be checked for this facility by measuring the power consumption in it during a certain period (year, season of operation) and under the condition of normal operation of the facility.

It is obvious that rationing is possible only with an established accounting of the consumption of electric energy in a given farm.

Regulation of load schedules plays a significant role in the rational use of electricity. The capacity of electrical networks (wires, transformers, etc.) is determined by the maximum design load: the more electricity will be transmitted through these networks during the day or year, the more they will be used and the higher the efficiency of power supply. Therefore, an ideal plot for a group of electric receivers would be a straight line parallel to the abscissa axis with an ordinate equal to the maximum load Pmax. Then the electricity consumption per day would be Wmax = Rta24.

In fact, the real load plot is always different from the ideal one in that most of the time the load is less than the calculated one.

To improve the situation, it is necessary, on the one hand, to turn on as few electric receivers as possible during maximum load hours, and on the other hand, to load the plant at night when possible. Very good electric receivers, which can level the schedule at night, are various electric heating devices with heat accumulation (electric boilers, furnaces, heated floors, etc.). At night, they store thermal energy, and then allow you to spend it during the day.

It is necessary to take all possible measures to increase the power factor in all links of the rural electric plant. The correct choice of electric motors in terms of power is one of the domestic measures. The power factor of the underloaded asynchronous motor is significantly lower than nominal. Therefore, when designing the plant, it is impossible to take increased power reserves, as well as use closed type engines where open ones can be used.

For many consumers, the duration of idling is 50... 60% of the total operation time, it is advisable to supply electric motors of such consumers with idling limiters.

In the presence of single-phase loads, equal-dimensional phase distribution is essential, especially at maximum load. Violation of symmetry leads, as already mentioned, to additional energy losses and voltage loss.

The greatest energy savings can be achieved with the introduction of energy-saving technologies. Calculations show that additional costs, which are usually required, in 2... 3 times less cost of additional power consumption. In addition, non-renewable energy resources are preserved - coal, gas, liquid fuel, uranium.

Currently, research is underway on the development of electric saving technologies in all sectors of the national economy, including agriculture.

It is very important to use renewable and secondary energy resources to reduce electricity consumption. So, first of all, you need to use the energy of the sun for thermal purposes.

Secondary fuel and energy resources represent waste of low-potential heat in various industrial enterprises, at thermal power plants (including nuclear power plants), metallurgical, chemical and other plants, in ventilation emissions of industrial and domestic facilities. They represent a significant proportion of primary energy sources and are approximately equal to the total volume of usable thermal energy. It is especially promising to use the thermal waste of gas compressor stations of gas pipelines, the number of which is growing rapidly.