Analysis of the influence of installed FACTS devices and transformer on-load tap changers (OLTC) in transmission networks on a total power losses Unified Energy System (UES) of Russia

Author(s):  
Vadim I. Zakutsky ◽  
Magomed G. Gadzhiev ◽  
Nikita S. Yermolov
Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4164
Author(s):  
Tomasz Szczegielniak ◽  
Dariusz Kusiak ◽  
Paweł Jabłoński

The use of high voltage power cables in distribution and transmission networks is still increasing. As a result, the research on the electrical performance of cable lines is still up to date. In the paper, an analytical method of determining the power losses and the temperature distribution in the medium voltage cable was proposed. The main feature of the method is direct including the skin and proximity effects. Then the Joule law is used to express the power losses in the conductor and screen, and the Fourier-Kirchhoff equation is applied to find out the temperature distribution in the cable. The research was focused on a cable with isolated screen and return current in the screen taken into account. The proposed method was tested by using the commercial COMSOL software(5.6/COMSOL AB, Stockholm, Sweden) as well as by carrying out laboratory measurements. Furthermore, the results obtained via the proposed method were compared with those given in literature. The differences between the temperature values calculated by the analytical method, numerical computations and obtained experimentally do not exceed 10%. The proposed analytical method is suitable in prediction the temperature of the power cables with good accuracy.


2017 ◽  
Vol 113 (11/12) ◽  
Author(s):  
Justine Rudman ◽  
Paul Gauché ◽  
Karen J. Esler

According to recent national energy plans and policy documents, the number of renewable energy developments is expected to increase in South Africa, thus contributing to the diversification of the country’s energy system. Consequently, numerous solar power developments are being deployed in the sunny arid interior – areas generally represented by the Nama-Karoo and Savanna Biomes. These developments come with a range of novel environmental impacts, providing opportunities for multidimensional exploratory research. Here, a mixed-method approach was used to identify and investigate possible environmental impacts associated with two types of solar power plants: concentrating solar power and photovoltaic. Structured interviews conducted with experts and experienced professionals, together with observations from site visits generated complementary findings. In addition to the risk of cumulative ecological impacts associated with individual solar plant developments, landscape impacts of multiple power plants and the direct impact on avifauna were found to be the most significant environmental impacts. These direct impacts appear to be most significant during the construction stage, which represents an intensive 10% of the total power plant lifespan. This investigation provides an early, broad and informative perspective on the experienced and expected impacts of solar power in South African arid regions as well as insights to possible future research areas.


This report largely focused on the influence on the delivery system of the Renewable Distributed Generations (RDGs). DG's intercourse showed that the suggested the traditional method of radial distribution into a multiple DG scheme. The main contribution of this study is to reduce total power losses and increase the distribution system's power quality using RDGs. The Loss sensitivity factor (LSF) is used to find the RDGs. A heuristic search novel The Modified Bat Algorithm (MBA) is used to define the amount of the RDGs. MBA is largely focused on microbats' higher elastic modulus. The proposed MBA is measured on standard bus test systems IEEE 33 and 69.


Author(s):  
Michael Westman ◽  
Ove Isaksson

This paper is concerned with forest logging machinery. A great deal of final felling in cut-to-length method done by harvester, which fells, delimbs and cuts the trees to pre-selected lengths. Two important criteria of a harvester head are that it has to be energy efficient and it has to be as fast as possible. To minimize losses in hydraulic systems the main demand is to reduce pressure losses in high power valves and outer components as much as possible. Each orifice in the flow path results in power losses. This work is an experimental study on power losses and acceleration of hydraulic motor in a system with long hoses. Main hydraulic components included are hydraulic pump, cartridge valve, pipe line and hydraulic motor. The results show that pre-activating the pump improves the system speed. To reduce losses, optimization of valve block, cartridge valve orifices are needed. Accumulators are favourable if combined with high stand-by pressure.


2021 ◽  
Vol 143 (11) ◽  
Author(s):  
A. Dindar ◽  
K. Chaudhury ◽  
I. Hong ◽  
A. Kahraman ◽  
C. Wink

Abstract In this study, an experimental methodology is presented to separate various components of the power loss of a gearbox. The methodology relies on two separate measurements. One is designed to measure total power loss of a gearbox housing a single spur gear pair under both loaded and unloaded conditions such that load-independent (spin) and load-dependent (mechanical) components can be separated. With the assumption that gear pair and rolling element bearings constitute the bulk of the gearbox power loss, a second measurement system designed to quantify rolling element bearing losses is proposed. With this setup, spin and mechanical power losses of rolling element bearings used in the gearbox experiments are measured. Combining the sets of gearbox and bearing data, power loss components attributable to the gear pair and rolling element bearings are quantified as a function of speed and torque. The results indicate that all gear and bearing related components are significant and a methodology such as the one proposed in this study is warranted.


2019 ◽  
Vol 6 (2) ◽  
pp. 7
Author(s):  
I. K. A. Wijaya ◽  
R. S. Hartati ◽  
I W. Sukerayasa

Saba feeder is a feeder who supplies 78 distribution transformers with feeder length 38,959 kms, through this Saba feeder electrical energy is channeled radially to each distribution substation. In 2017 the voltage shrinkage at Saba feeder was 9.88% (18,024 kV) while the total power loss was 445.5 kW. In this study an attempt was made to overcome the voltage losses and power losses using the method of optimizing bank capacitors with genetic algorithms and network reconfiguration. The best solution obtained from this study will be selected for repair of voltage losses and power losses in Saba feeders. The results showed that by optimizing bank capacitors using genetic algorithms, the placement of capacitor banks was placed on bus 23 (the channel leading to the BB0024 transformer) and successfully reduced the power loss to 331.7 kW. The network reconfiguration succeeded in fixing the voltage on the Saba feeder with a voltage drop of 4.75% and a total power loss of 182.7 kW. With the combined method, reconfiguration and optimization of bank capacitors with genetic algorithms were obtained on bus 27 (channel to transformer BB0047) and managed to reduce power losses to 143 kW.


2015 ◽  
Vol 14 (2) ◽  
pp. 27
Author(s):  
I Made Gusmara Nusaman ◽  
I Wayan Sukerayasa ◽  
Rukmi Sari Hartati

The distributed generation technology or in this case abbreviated DG is a kind of power plants with small scale which prioritizes the utilization of renewable energy resources such as wind, water, solar, geothermal, ocean waves (Wave Energy), ocean currents (Ocean Current Energy), biomass, and biogass to produce the electrical energy with range of power generation between 1 kW-10 MW. One of the DG in Bali and still in operation is the garbage power plant which located in Suwung, South Denpasar. An analysis has been done using load flow analysis and reliability assessment to determine the effect of DG interconnection against the power losses and the level of reliability on the Serangan feeder. Based on the research that has been done, DG intercon-nection on the Serangan feeder decrease the power losses and increase the reliability and it can visible from the acquisition of SAIFI and SAIDI index which decreased. The best location of DG interconnection to get low of the power losses and the high level of reliability is at 97% from the total length of the feeder. At that location the power losses is decrease as big as 4.5 kW or 11.25% of the total power lossess without the DG interconnection and decrease of the SAIFI and SAIDI index respectively to 0.1 failure/customers/year and 1.4150 hour/ customer/year


Volume 4 ◽  
2004 ◽  
Author(s):  
K. Altaii ◽  
A. Bradway ◽  
A. M. Al-Jumaily

This paper presents the modeling and simulation of a hybrid renewable-energy system. The sizing, availability, and contribution of solar photovoltaic, wind energy and hydro energy can be simulated to determine the viability, stability, and cost effectiveness of such systems. The model allows the user to enter site specific data (hourly, daily, monthly, and annually) such as solar radiation, wind speed and precipitation. Users can select the type and size of wind turbine, hydroelectric turbine, photovoltaic panel and the electrical load placed on the hybrid renewable system. The simulation will determine the total power that can be produced on an hourly, daily, monthly and annual basis, the optimum combination of renewable energies, and usage/storage of each type of renewable energies, given the specified system and the collected data. With the help of HyRES, the model, one can determine which hybrid renewable energy system would best suit a specific site, and also help to determine which type of wind turbine, hydroelectric turbine, or photovoltaic panels would best complement each other for that site.


2018 ◽  
Author(s):  
Xiaoyu Yang ◽  
Hongbin Zhao

Distributed energy technology is an important developing direction of the future energy technology. This paper puts forward a distributed energy system named SOFC-GT-RC with LNG as fuel and recovering carbon dioxide. In the system, the cold energy of LNG can not only cool the compressor inlet air to reduce consumption of compressor work, but also to supply cold energy and to get zero-CO2 and other emissions. Based on mathematical model of each part, the thermodynamic calculation model of the whole system is built by FORTRAN, which is embedded in ASPEN PLUS. The results of calculation indicate the thermal efficiency and total power efficiency are 74.5% and 56.7% while the exergy efficiency is 61.8%. In addition, some operating parameters such as fuel utilization factor and fuel flow rate are selected. Based on these operating parameters, the new system thermodynamic performance is studied. The results point that this SOFC-GT-RC system fueled by LNG increases the total power, decreases waste of cold energy and the pollution of the environment, which would be an effective utilization style of energy in China’s LNG satellite stations.


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