Conversion of Electrical Energy in the Processes of Its Generation and Transmission

Electrical energy can be obtained by burning coal (thermal power plant), by using nuclear fuel (nuclear power plant) or by using the power of water (hydro power plant). In these cases, the energy obtained by the sources put a shaft of an electrical generator in motion. The generator generates electrical energy – see Figure 1. In the installation, excitation system for the generator is used. The system turns on an uncontrolled rectifier, thyristor-controlled rectifier or AC thyristor regulator dependent on the generator type. The obtained energy is transmitted using a transmission system towards consumers. The transmission yet is made mainly in high-voltage AC energy form (HVAC). In different parts of the transmission network the voltage value may be different. There are so-called high-voltage (420 kV, 220 kV, 110 kV, etc) and medium voltage (20 kV, 6.6 kV, etc.) systems. General consumers consume electrical energy from so-called low-voltage systems (230V, 50Hz or 110V, 60Hz). During the transmission the type of energy does not change, only the value of the voltage changes using transformers.

Author(s):  
Josifs Survilo ◽  
Antons Kutjuns

Operation Modes of HV/MV SubstationsA distribution network consists of high voltage grid, medium voltage grid, and low voltage grid. Medium voltage grid is connected to high voltage grid via substations with HV/MV transformers. The substation may contain one, mostly two but sometimes even more transformers. Out of reliability and expenditure considerations the two transformer option prevail over others mentioned. For two transformer substation, there may be made choice out of several operation modes: 1) two (small) transformers, with rated power each over 0.7 of maximum substation load, permanently in operation; 2) one (big) transformer, with rated power over maximum substation load, permanently in operation and small transformer in constant cold reserve; 3) big transformer in operation in cold season, small transformer-in warm one. Considering transformer load losses and no load losses and observing transformer loading factor β it can be said that the mode 1) is less advantageous. The least power losses has the mode 3). There may be singled out yet three extra modes of two transformer substations: 4) two big transformers in permanent operation; 5) one big transformer permanently in operation and one such transformer in cold reserve; 6) two small transformers in operation in cold season of the year, in warm season-one small transformer on duty. At present mostly two transformers of equal power each are installed on substations and in operation is one of them, hence extra mode 5). When one transformer becomes faulty, it can be changed for smaller one and the third operation mode can be practiced. Extra mode 4) is unpractical in all aspects. The mode 6) has greater losses than the mode 3) and is not considered in detail. To prove the advantage of the third mode in sense of power losses, the notion of effective utilization time of power losses was introduced and it was proven that relative value of this quantity diminishes with loading factor β. The use of advantageous substation option would make it possible to save notable amount of electrical energy but smaller transformer lifetime of this option must be taken into account as well.


2021 ◽  
Vol 8 (2) ◽  
pp. 290
Author(s):  
Shaleh Raed Shatat ◽  
Ade Riusma Ariyana ◽  
Devina Arifani

The states Nuclear Program is a program to build and utilize nuclear science and technology both in the non-energy sector and in the energy sector for peaceful purposes. Utilization of non-energy in Indonesia has developed quite advanced. The use of nuclear power in every countries covers various fields such as health, research and industry. Indonesia's readiness in implementing nuclear energy is carried out by ratifying international conventions, issuing laws, and issuing regulations from the Nuclear Energy Supervisory Agency, readiness in the field of infrastructure used to strengthen technology, and in Indonesia is committed to reducing 26% of greenhouse gas emissions in the year 2020. A nuclear power plant or nuclear power plant is a thermal power plant that uses one or more nuclear reactors as a heat source. The working principle of a nuclear power plant is almost the same as a steam power plant, using high pressure steam to turn a turbine. The rotation of the turbine is converted into electrical energy. The difference is the heat source used to generate heat. A nuclear power plant uses uranium as its heat source. The fission reaction (fission) of the uranium nucleus produces enormous heat energy. The power of a nuclear power plant ranges from 40 MWe to 2000 MWe, and a nuclear power plant built in 2005 has a power distribution from 600 MWe to 1200 MWe. As of 2015 there are 437 nuclear power plants operating in the world, which in total generate about 1/6 of the world's electrical energy. To date, around 66 nuclear power plants are being built in various countries, including China with 28 units, Russia with 11 units, India with 7 units, the United Arab Emirates with 4 units, South Korea with 4 units, Pakistan and Taiwan with 2 units each. Nuclear power plants are categorized based on the type of reactor used. However, in some plants that have several separate reactor units, it is possible to use reactor types that are fueled such as Uranium and Plutonium.


Author(s):  
Devendra Panchal ◽  
Patane R. D.

Power plant is used to production of electricity by so many types of technology. Like Hydro power plant, Thermal power plant, Nuclear power plant, Gas turbine power plant, combined cycle power plant, solar power plant, Wind power plant, Tidal power plant, Diesel generator, petrol generator, this all are power plant run by fuel and generate electricity. I am introducing new type and technology power plant.


Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.


Author(s):  
Alexey Dragunov ◽  
Eugene Saltanov ◽  
Igor Pioro ◽  
Pavel Kirillov ◽  
Romney Duffey

It is well known that the electrical-power generation is the key factor for advances in any other industries, agriculture and level of living. In general, electrical energy can be generated by: 1) non-renewable-energy sources such as coal, natural gas, oil, and nuclear; and 2) renewable-energy sources such as hydro, wind, solar, biomass, geothermal and marine. However, the main sources for electrical-energy generation are: 1) thermal - primary coal and secondary natural gas; 2) “large” hydro and 3) nuclear. The rest of the energy sources might have visible impact just in some countries. Modern advanced thermal power plants have reached very high thermal efficiencies (55–62%). In spite of that they are still the largest emitters of carbon dioxide into atmosphere. Due to that, reliable non-fossil-fuel energy generation, such as nuclear power, becomes more and more attractive. However, current Nuclear Power Plants (NPPs) are way behind by thermal efficiency (30–42%) compared to that of advanced thermal power plants. Therefore, it is important to consider various ways to enhance thermal efficiency of NPPs. The paper presents comparison of thermodynamic cycles and layouts of modern NPPs and discusses ways to improve their thermal efficiencies.


Author(s):  
A. V. Lykin ◽  
E. A. Utkin

The article considers the feasibility of changing the structure of a distribution electrical network by transferring points of electricity transformation as close to consumers as possible. This approach is based on installation of pole-mounted transformer substations (PMTS) near consumer groups and changes the topology of the electrical network. At the same time, for groups of consumers, the configuration of sections of the low-voltage network, including service drops, changes. The efficiency of approaching transformer substations to consumers was estimated by the reduction in electrical energy losses due to the expansion of the high-voltage network. The calculation of electrical losses was carried out according to twenty-four hour consumer demand curve. To estimate the power losses in each section of the electrical network of high and low voltage, the calculated expressions were obtained. For the considered example, the electrical energy losses in the whole network with a modified topology is reduced by about two times, while in a high-voltage network with the same transmitted power, the losses are reduced to a practically insignificant level, and in installed PMTS transformers they increase mainly due to the rise in total idle losses. The payback period of additional capital investments in option with modified topology will be significantly greater if payback is assessed only by saving losses cost. Consequently, the determination of the feasibility of applying this approach should be carried out taking into account such factors as increasing the reliability of electricity supply, improving the quality of electricity, and increasing the power transmission capacity of the main part of electrical network.


2017 ◽  
Vol 3 (1) ◽  
pp. 107
Author(s):  
Jan-Erik Lane

<p><em>As the Latin American countries have hardly started developing implementation strategies of the agreed upon COP21 objectives, their situation should be more researched. The CO2:s are really high in 2 countries but medium in all the others; Mexico and Brazil that face enormous difficulties with global warming. Thus, the dominant energy reliance remains much fixed upon oil and natural gas, but with some third component like hydro, geothermal or biomass power. Hydro power is used much but it presents a risk as it requires lots of water, which further global warming may deny—look at Venezuela today. Brazil’s plans for 30 new dams in the Amazons together with ongoing logging and new agriculture will destroy the rain forest Major investments in wind, solar, geo-thermal power or/and nuclear power are called for, besides the plenty biomass and hydro power. But to make a great energy transformation towards renewables and atomic power, the Latin American countries need massive assistance from the promised Super Fund. Only Uruguay has come far with the changes towards renewables, producing electricity with 100% renewables, including wind power.</em></p>


Author(s):  
Dinesh Kanvagiya

Abstract: Generating more Power are complex at cheaper cost, also continuous energy supplied are important Hydro power generation is one of the most successful renewable energy resources for the production electrical energy without any environmental hazard and presently it providing more than 86% of all electricity generated by renewable sources worldwide and accounts for about 20% of world electricity. To increase the percentage of green energy in account of world electricity generation the analysis must be performed to get the information about the working conditions of each component in plants so that the required maintenance action should be taken. Maintenance and operation of a hydro power plant is very complicated and the process to calculate and analyzing its compatibility and reliability is very important. In this work introducing a Markov model to evaluate the reliability parameter of THPS-I Sirmour, Rewa. For this work the operational data regarding failure and maintenance time taken to repaired and analysis of all parts of generating unit of the power plant for period of 2010-2015 is considered. The availability and reliability of individual unit of power plant is evaluated by taking into account different reliability Parameters, namely failure rate (λ), repair rate (µ), MTTR, MTTF, MTBF through the collected data and tabulating the required information for the analysis. By this analysis work we can improve reliability of all the components of each unit of power plant. The sub-unit that is commonly failed during operation is like- penstock, butter fly valve, spiral case, turbine, generator, excitation system, speed governor etc. Reliability plays a key role in the cost-effectiveness of systems Keywords: Hydro power plant, Reliability evaluation, Reliability parameters, Markov analysis, Total schedule outage hrs and Total forced outage hrs.


2021 ◽  
Vol 23 (3) ◽  
pp. 10-17
Author(s):  
Ivan Vujović ◽  
Željko Đurišić ◽  

Telecommunications and computer equipment centralisation trends for the purpose of achieving economic benefits, usage of technological innovations and new technical solutions implementation leads to the requirements for building bigger Data Centres (DCs). An increase in the size of the DC facility i.e. the number of racks inside occupied with equipment and the number of devices that enables the proper functioning of that equipment leads to necessarily power energy requirements increasing for power supply. For the DCs that require a large amount of energy, the building of their own, usually renewable energy sources (RES) is cost-effective. In such a caser, RES are primary and Power System (PS) is secondary and redundant power source. A concept of a DC primary powered from RES is presented in this paper. Generated electrical energy in RES is transmitted in PS through high voltage switch-gears (SGs) while DC is power supplied from PS through low voltage, medium voltage and high voltage SG-s. For the purpose of realisation of such facility, it is necessary to enable adequate conditions related to geographical location, physical access to the facility, possibility of connecting to the PS and possibility of connecting to the telecommunications centres. Based on carried out researches related to RESs potential, available roads, power supply infrastructure and telecommunication infrastructure, development conditions for DC on location near to Belgrade, close to power transformer station „Belgrade 20“ are analysed in this paper. From the aspect of DC power supply, proposed solution includes wind farm, solar plant and landfill gas power plant, as well as related SGs. Telecommunication connections from DC to the PS and other important telecommunication centres are provided. These connections are realised through optical cables placed next to the electrical lines and cables, and, when that is not possible, placed independently in the ground. The design of the DC interior is given and calculations of the required electrical energy for the power supply of the equipment and devices in the facility are performed. Based on calculation results, capacity calculation of the RES and calculation of SGs are performed. Design of the interior optical connections inside DC is also given. A General assessment of the investment and economics of building such DC are given at the end of the paper.


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