Electrical supply of mechanical repair shop

Contents

1 Energy development in Russia 2 2 Voltage and current selection

3 Selection of power distribution scheme

4 Calculation of electrical loads

5 Reactive power compensation

6 Selection of number and power of transformers, type of substation

7 Calculation of transformer power losses

8 Calculation and selection of networks above 1kV

9 Calculation and selection of networks with voltage up to 1kV

10 Calculation of short-circuit currents

11 Selection of equipment and its check for action of short currents

short circuits

12 Relay protection in power grids

13 Calculation of grounding device

List of literature

1 Energy development in Russia

Electricity is the basic industry of the Russian economy, providing the needs of the national economy and the population for electricity and heat power and the export of electricity to the CIS and non-CIS countries. The country's energy security largely depends on sustainable and reliable work.

With the growth of production in industry, the electric power industry becomes one of the life-sustaining sectors of the economy and one of the factors of economic development, and its reliable functioning is an essential condition for Russia's transition to a high standard of living and standard of living.

The prospects for the development of the electric power industry are determined by the Energy Strategy of Russia for the period up to 2020, which was approved by the Government of the Russian Federation on August 23, 2003.

As at present, in the future, the structure of inputs of generating capacities will determine the features of the territorial location of fuel and energy resources: new nuclear power plants should be built in European regions of the country, and in particular in the Urals and the Far East; it is advisable to build hydroelectric power plants mainly in Siberia and the Far East; coal-fired thermal power plants will have to be introduced not only in Siberia and the Far East, but also in the European regions of the country; when modernizing gas-gas thermal power plants, the main direction will be the replacement of steam turbines with steam-gas plants in new buildings on the same areas, and the construction of gas thermal power plants will be carried out based on gas resources.

In the future, the role and importance of nuclear energy in ensuring reliable electricity supply to consumers will increase. Russia's energy strategy is planned with a favorable development option to increase electricity production at nuclear power plants to 195 billion kWh in 2010, and in 2020. - up to 300 billion kWh, for which it is necessary to introduce 3436 million kW of capacity at the NPP before the last specified period.

In conditions of uneven distribution of fuel resources, the hydropower development program is more important. So until 2010. the construction of the Bureya hydroelectric power station in the Far East, Zaramagaskaya, Zelenoguksky and a cascade of NizhneCherekskiy hydroelectric power stations in the North Caucasus has to be complete, input of capacities on hydroelectric power stations under construction, the largest of which are Boguchansky hydroelectric power station in Siberia, UstSrednekanskiy hydroelectric power station in the Far East, Irganaysky hydroelectric power station in the North Caucasus, is begun.

After 2010 It is envisaged to continue economically justified hydropower construction with the introduction of 3-4 million kW of capacity into the five-year plan to hydroelectric power plants. In accordance with this 2011 2020. the construction of the Boguchanskaya hydroelectric power station in Siberia, the Lower Bureyskaya and Vilyuyskaya hydroelectric power stations in the Far East should be completed. It is also necessary to bring the construction of the South Yakutsk hydropower complex and the construction of the hydroelectric power station cascade on the lower Hangar closer to the beginning, in order to introduce the first unit of head hydroelectric power stations until 2020.

In addition, JSC RAO UES of Russia is studying the possibilities of constructing the Gurukhan hydroelectric power station with an installed capacity of 12 million kW and with an annual generation of 46 billion kW of electricity. The implementation of this project would make the Turukhan hydroelectric power station the largest power plant in Russia, putting it on a par with such grandees of world hydropower as the Itaipu hydroelectric power station in Brazil and the Three Gorges hydroelectric power station in China .

Thermal power plants will remain the basis of the electric power industry for the entire future under consideration, the share of which in the structure of the installed capacity of the industry will remain at the level of 6265%. Electricity generation at TPP by 2020, as planned, will increase 1.4-1.5 times compared to 2001. and may amount to 655-690 billion kWh per year by 2010. and 790-850 billion kW 2020.

The need to radically change the conditions for fuel supply of thermal power plants in European regions of the country and tougher environmental requirements lead to the need for the early introduction of new technologies in thermal power. For gas-fired thermal power plants, such technologies are primarily the steam-gas cycle, gas turbine superstructures of steam power units and gas turbines with heat utilization; for thermal power plants using solid fuel, these are environmentally friendly coal combustion technologies using generator gas in steam plants. The transition from steam-turbine to steam-gas thermal power plants should provide an increase in the efficiency of plants up to 50%, and in the future up to 60% or more.

The construction of new coal power units for supercritical steam parameters (30 mPa, 600 С) should be considered an important area of ​ ​ increasing thermal economy. At such power units, the efficiency can reach 4546%, which will significantly reduce the increase in the fuel demand of TPP.

The promising development of the main electric network of the UES of Russia is aimed at achieving its stable and reliable functioning in the conditions of a competitive wholesale market for capacity and electricity. The total length of the overhead power transmission line with a voltage of 330 kV and above, which will be introduced for the period up to 2020, should be 2535 thousand km depending on the development option.

In order to eliminate technical constraints that hinder the formation of a competitive environment, special attention will be paid to the development of system-forming electric networks, which will ensure: full output of the capacity of large power plants, including nuclear power plants; reliable power supply to consumers; implementation of intersystem effects from joint operation of all integrated power systems within the EEC; export of electricity and capacity to the power systems of neighboring states and parallel work with the power systems of the CIS and Baltic countries .

The highest voltage classes in the UES of Russia for the considered future remain 1150 kV for AC networks and 1500 kV for direct current transmission. The feasibility of using these voltage classes effectively will be determined as the fuel and energy potential of the eastern regions of the country and the European part of Russia is involved in the balance structure of the industry.

The priority tasks of the development of inter-system electrical connections are: strengthening communication between the eastern and European parts of the UES of Russia by building overhead power lines with voltages of 500 and 1150 kV, and after 2010. and DC transmission. This will reduce the plant of eastern chains in the European regions of the country, as well as more fully use the capacity of TPP and hydroelectric power stations in Siberia: transferring intersystem connections between ECO to 750 and 500 kV; provision of services for transportation and distribution of electricity.

An important task of the Energy Strategy for the period up to 2020. is the integration of the EEC of Russia with the energy systems of the CIS countries and neighboring states of Europe and Asia on new mutually beneficial conditions .

2 Voltage and current selection

When selecting the rated voltage of the external section of the network, the existing voltages of possible power sources of the power system, the distance from the sources to the enterprise and the load of the enterprise as a whole are taken into account.

Power supply and distribution networks of small and medium-sized enterprises use rated voltages of 6 and 10 kV. As a rule, the voltage U = 10 kV should be used as more economical than the voltage U = 6 kV. 6 kV voltage is used when electric receivers with voltage U = 6 kV prevail on the object. In some cases, power supply of electric receivers with voltage U = 6 kV is carried out via supply lines with voltage 10 kV with subsequent transformation to voltage 6 kV directly for these electric receivers. In this course design, voltage from the high side U = 10 kV is used. The networks are made with a 3x35 AAShv cable laid in a trench.

There are two types of current: direct and alternating. The DC current type is used if the enterprise has DC electric receivers. Since in this academic year project is not present such, the three-phase variable sort of current of the industrial frequency of ƒ1 = 50 Hz is applied.

3 Selection of power distribution scheme

Electrical networks inside the facility are made according to trunk, radial and mixed circuits.

The main power distribution circuit has the following advantages: better cable loading in normal operation mode, fewer cameras from RP. Disadvantages include the complication of switching circuits when connecting a TC and the simultaneous disconnection of several consumers powered by the main line when it is damaged.

The radial power distribution scheme has great flexibility and ease of operation, since damage or repair of one line affects the operation of only one consumer. But this power distribution scheme requires a lot of materials and money.

In this CP, a mixed power distribution scheme combines the principles of radial and trunk power distribution schemes.