Voltage Profile Improvement of Distribution System via Integration of Distributed Generation Resources

This study attempts to identify the causes and possible solutions for voltage profile issues in the lower land of Nepal, and is specifically focused on Laukahi feeder, a radial distribution system with an approximate length of 65 km and distributed at 11KV system voltage. Currently, the end-users feeding through this feeder are getting extremely poor voltage along with frequent interruptions in the power supply. In this study, a forward/ backward sweep algorithm is used to analyze the load flow of the distribution system, whereas ant colony optimization (ACO) technique is used to identify the best location for the Distributed Generator (DG) penetrations. After completion of this study, it is found that, the branch loss of the feeder can be reduced up to 87.22%, and voltage profile can be improved from 0.828 pu to 0.982 pu by integrating some form of DGs

Analysis of the Effect of Loading on the Transformers Usage Time

The reliability and stability of the system in the operation of the electric power system is very important, in order to provide comfort in service to consumers. The transformer is a very important component in the electric power system, because it is used as a voltage adjuster for the load being served. This study discusses the effect of loading and temperature on the life shrinkage of 36/60 MVA power transformers in block 3 and block 4 carried out at PT. PJB UBJ O&M PLTMG Arun Lhokseumawe, Aceh. From the calculation results after 4 years the transformer operates, if the transformer is given a 100% load, the transformer will experience an age difference of 2.52 p.u/day so that it has a remaining life for of 10 years. As for the transformer that is given a load of 90%, the transformer will experience an age difference of 1.44 p.u/day so that it has a remaining life to perform operations for another 18 years. Then for a transformer that is given a load of 80%, the transformer will experience an age difference of 0.67 p.u/day so that it will have a remaining life to carry out the operation again for another 38 years. From the above calculation, the origin of the temperature obtained for the ONAN type of cooler in block 3 is 0.71 p.u/day and in block 4 it is 0.70 p.u/day. While the ONAF type of cooler in block 3 is 0.004 p.u/day and in block 4 it is 0.005 p.u/day. This is in accordance with the regulation SPLN50/1982 regarding transformer life shrinkage

Assesment of electricity excess in an isolated hybrid energy system: A case study of a Dangiwada village in rural Nepal

The increasing demand of power can be fulfilled through different architectures and electricity supply models by utilizing the available local resources. But most of the isolated energy system suffers from high energy cost and unreliable energy supply. This study identifies different electricity supply models to fulfill the dynamic demand of power in a remote area, which is analyzed in terms of cost of energy and causes for the high cost of energy. Among different factors, the presence of unusable energy (Electricity Excess) produced by the energy system during fulfillment of the demand is found to be major one cause for the high cost of energy. Further, the importance of energy storage system in isolated energy system is discussed. In this case, up to 83.4 % of electricity excess is observed, which can be utilized in different manners to reduce the total energy cost. Electricity excess profile for different energy model, their impacts and possible techniques of the solution with open views are discussed

Status of Pure Electric Vehicle Power Train Technology and Future Prospects

Electric vehicles (EV) are becoming more common mobility in the transportation sector in recent times. The dependence on oil as the source of energy for passenger vehicles has economic and political implications, and the crisis will take over as the oil reserves of the world diminish. As concerns of oil depletion and security of the oil supply remain as severe as ever, and faced with the consequences of climate change due to greenhouse gas emissions from the tail pipes of vehicles, the world today is increasingly looking at alternatives to traditional road transport technologies. EVs are seen as a promising green technology which could lead to the decarbonization of the passenger vehicle fleet and to independence from oil. There are possibilities of immense environmental benefits as well, as EVs have zero tail pipe emission and therefore are capable of curbing the pollution problems created by vehicle emission in an efficient way so they can extensively reduce the greenhouse gas emissions produced by the transportation sector as pure electric vehicles are the only vehicles with zero-emission potential. However, there are some major barriers for EVs to overcome before totally replacing ICE vehicles in the transportation sector and obtain appreciable market penetration. This review evaluates the technological aspects of the different power train systems of BEV technology and highlights those technological areas where important progress is expected by focusing on reviewing all the useful information and data available on EV architecture, electrical machines, optimization techniques, and its possibilities of future developments as green mobility. The challenges of different electric drive trains’ commercialization are discussed. The major objective is to provide an overall view of the current pure electric vehicle powertrain technology and possibilities of future green vehicle development to assist in future research in this sector