scholarly journals A simplified PWM technique for PV fed Five-Level Five switch Multilevel Inverter

2018 ◽  
Vol 7 (4.24) ◽  
pp. 4
Author(s):  
Ali Qasim Hussein Algburi ◽  
P. V. Ramana Rao

Bulk electrical power generation is generated using fossil fuels which emit huge pollution which is a global constraint today. Non-conventional sources of energy are the alternative energy sources for power generation. Non-conventional sources like PV (photo-voltaic) system are used as power source now-a-days. Multi-level inverters (MLI) are dominating inverter circuits giving out voltage with less distortion eventually reducing voltage stress on switches and size of filter. This paper presents a MLI structure with five switches giving out five-level output from the inverter. PV system is used as source and boost converter amplifies the PV output voltage to desired value. The paper presents a simplified PWM (pulse width modulation) technique for PV fed five switch five-level inverter. The proposed system is developed and results are obtained using MATLAB/SIMULINK software. Results are presented for the system considering R-load and RL-load conditions.

2012 ◽  
Vol 46 (5) ◽  
pp. 12-23 ◽  
Author(s):  
Robert H. Weisberg ◽  
Yonggang Liu ◽  
Clifford R. Merz ◽  
Jyotika I. Virmani ◽  
Lianyuan Zheng

AbstractUsing observations of surface winds, solar radiation, ocean currents and waves collected by the University of South Florida, Coastal Ocean Monitoring and Prediction System (COMPS), augmented by other data and numerical model simulations, we address the potential for electrical power generation for Florida by harnessing the natural energy sources of wind and solar, along with ocean currents and waves. We begin by identifying what nature offers. For wind and solar, we use specifications from existing, commercially available devices to convert nature’s bounty to power-generation estimates. In the absence of mature, commercially available devices for ocean currents and waves, we draw upon physical principles to arrive at power-generation estimates for these potential sources. On the basis of what nature offers and what machinery may be capable of producing, we then make reasonable extrapolations on what these estimations may mean in a practical sense for supplying energy to society. Power generation from these naturally occurring, alternative energy sources, particularly wind and solar, may provide a means for supplementing power generation by conventional fuels but does not provide a replacement for conventional fuels.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Farhana Umer ◽  
Muhammad Shehzad Aslam ◽  
Muhammad Shoaib Rabbani ◽  
Muhammad Javed Hanif ◽  
Nadeem Naeem ◽  
...  

In recent years, the upturn demand of electricity and the generation of electrical power demand from fossil fuels are increasing day by day which results in environmental impacts on the atmosphere by greenhouse gases, and a high cost of electric power from these sources makes it unaffordable. The use of renewable energy sources can overcome this problem. Therefore, in this work, we present a solution by implementing the solar car parking lots. A detailed work has been done for solar car parking site selection and maximum solar electric power generation and its capacity effects with the shading of nearby trees and buildings by using the HelioScope online software developed by Folsom Labs. A detailed optimization and selection of car parking canopies are performed at different standard tilt angles to produce maximum solar photovoltaic energy, and it is analyzed that the monopitch canopy is the best to mount at solar car parking lots at a tilt angle of 10°. We have done a detailed economic analysis which shows that 14% electricity cost was offset by the installation of a solar car parking lot with 17% reduction in annual energy consumption from the grid at the proposed site. The total investment cost of the parking structure and the photovoltaic (PV) system can be paid back in 6-7 years.


Author(s):  
Yas A. Alsultanny ◽  
Eiman Alharbi

The renewable energy sources were considered as a potentially promising and far less harmful alternative to traditional methods of electrical production. The main aim of this paper is to evaluate the seasonal weather influence on the electrical power generation from solar cells. Experimental and quantitative methodologies were used to analysis the data were collected from two sources the primary data were collected from PhotoVoltaic (PV) system of capacity 1200W for one year. The second source of data were collected from the Kuwait Directorate General of Civil Aviation. The key findings of the results showed that the daily sunlight hours are considered an important factor for electrical power generation; the temperature had reverse impact when it raised to more than 30oC, and the relative humidity had reverse impact when it raised to more than 49%. The CO2 avoided by this system was 1.325tonnes per year. The recommendation of this study is to depend on PV cells to reduce dependence on fossil fuels.


Author(s):  
S. Nagaraja Rao ◽  
D. V. Ashok Kumar ◽  
Ch. Sai Babu

<table width="0" border="1" cellspacing="0" cellpadding="0"><tbody><tr><td valign="top" width="593"><p>The conventional energy sources available to us are on the verge of depletion. This depletion of conventional energy source leads to concentrate more on alternative energy sources. In this research, the focus is on the role of renewable energy sources (RES) in electrical power generation. Even though, the RES based plants produce power, we cannot directly connect it to the grid or loads. Because, the voltage ratings and nature supply of RES plants would not match with the load. Hence, this is a major issue for connecting RES plants to load or other utility. The power electronic converters are extensively being used as a link between load and supply. As most of the renewable energy power generation is DC in nature, the DC-DC converter is used to increase the voltage level and this DC must be converted to AC for grid connection. Therefore, inverters are used for DC to AC conversion. In this paper, the DC supply of renewable energy is connected to load by using cascade DC-DC converters along with a proposed reversing voltage (RV) multilevel inverter (MLI). The first DC-DC converter is used to enhance the voltage level with high gain and second converter is used to split the DC supply for inverter convenience. In this paper, proposed RV symmetrical and asymmetrical MLI generates 7, 9, 11, 13 and 15 levels with only ten power switches. In-phase level-shifted triangular carrier type sine pulse width modulation (PWM) technique is employed to trigger the commutating switches of proposed RV MLI. Switches of H-Bridge for reverse voltage appearance across the load are triggered by simple pulse generator. The circuits are modeled and simulated in MATLAB/SIMULINK software. Results are presented and discussed.</p></td></tr></tbody></table>


Author(s):  
Kau-Fui Vincent Wong ◽  
Guillermo Amador

As society continues advancing into the future, more energy is required to supply the increasing population and energy demands. Unfortunately, traditional forms of energy production through the burning of carbon-based fuels are dumping harmful pollutants into the environment, resulting in detrimental, and possibly irreversible, effects on our planet. The burning of coal and fossil fuels provides energy at the least monetary cost for countries like the US, but the price being paid through their negative impact of our atmosphere is difficult to quantify. A rapid shift to clean, alternative energy sources is critical in order to reduce the amount of greenhouse gas emissions. For alternative energy sources to replace traditional energy sources that produce greenhouse gases, they must be capable of providing energy at equal or greater rates and efficiencies, while still functioning at competitive prices. The main factors hindering the pursuit of alternative sources are their high initial costs and, for some, intermittency. The creation of electrical energy from natural sources like wind, water, and solar is very desirable since it produces no greenhouse gases and makes use of renewable sources—unlike fossil fuels. However, the planning and technology required to tap into these sources and transfer energy at the rate and consistency needed to supply our society comes at a higher price than traditional methods. These high costs are a result of the large-scale implementation of the state-of-the-art technologies behind the devices required for energy cultivation and delivery from these unorthodox sources. On the other hand, as fossil fuel sources become scarcer, the rising fuel costs drive overall costs up and make traditional methods less cost effective. The growing scarcity of fossil fuels and resulting pollutants stimulate the necessity to transition away from traditional energy production methods. Currently, the most common alternative energy technologies are solar photovoltaics (PVs), concentrated solar power (CSP), wind, hydroelectric, geothermal, tidal, wave, and nuclear. Because of government intervention in countries like the US and the absence of the need to restructure the electricity transmission system (due to the similarity in geographical requirements and consistency in power outputs for nuclear and traditional plants), nuclear energy is the most cost competitive energy technology that does not produce greenhouse gases. Through the proper use of nuclear fission electricity at high efficiencies could be produced without polluting our atmosphere. However, the initial capital required to erect nuclear plants dictates a higher cost over traditional methods. Therefore, the government is providing help with the high initial costs through loan guarantees, in order to stimulate the growth of low-emission energy production. This paper analyzes the proposal for the use of nuclear power as an intermediate step before an eventual transition to greater dependence on energy from wind, water, and solar (WWS) sources. Complete dependence on WWS cannot be achieved in the near future, within 20 years, because of the unavoidable variability of these sources and the required overhaul of the electricity transmission system. Therefore, we look to nuclear power in the time being to help provide predictable power as a means to reduce carbon emissions, while the other technologies are refined and gradually implemented in order to meet energy demand on a consistent basis.


2021 ◽  
Author(s):  
Zeynu Shamil Awol ◽  
Rezika Tofike Abate

Abstract Biomass energy is renewable energy source that comes from the material of plants and animals. Forms of biomass energy are bio-ethanol, bio methanol, and biodiesel. Bio-ethanol is one of the most important alternative energy sources that substitute the fossil fuels. The focus of this research is to produce bio-ethanol from waste office paper. Five laboratory experiments were conducted to produce bio-ethanol from wastepaper. The wastepaper was dried in oven and cut in to pieces. Then it passed through dilute acid hydrolysis, fermentation and distillation process respectively. High amount of ethanol was observed at 20 ml/g (liquid to solid ratio) and at the time of 2hr. Cost and economic analysis for ethanol production from wastepaper was performed. Results from the analysis indicated a paper to ethanol plant was feasible from the economic point of view with rate of return (RR) 38.61% and the payback period of 2.2 years.


2016 ◽  
Vol 19 (3) ◽  
pp. 96-109
Author(s):  
Phung Thi Kim Le ◽  
Viet Tan Tran ◽  
Thien Luu Minh Nguyen ◽  
Viet Vuong Pham ◽  
Truc Thanh Nguyen ◽  
...  

Finding alternative energy sources for fossil fuels was a global matter of concern, especially in developing countries. Rice husk, an abundant biomass in Viet Nam, was used to partially replace fossil fuels by gasification process. The study was conducted on the pilot plant fixed bed up-draft gasifier with two kind of gasification agents, pure air and air-steam mixture. Mathematical modeling and computer simulations were also used to describe and optimize the gasification processes. Mathematical modeling was based on Computational Fluid Dynamics method and simulation was carried by using Ansys Fluent software. Changes in outlet composition of syngas components (CO, CO2, CH4, H2O, H2) and temperature of process, in relation with ratio of steam in gasification agents, were presented. Obtained results indicated concentration of CH4, H2 in outlet was increased significantly when using air-steam gasification agents than pure air. The discrepancies among the gasification agents were determined to improve the actual process.


2018 ◽  
Vol 182 ◽  
pp. 01018
Author(s):  
Sławomir Wierzbicki ◽  
Michał Śmieja

The limited resources of fossil fuels, as well as the search for a reduction in emissions of carbon dioxide and other toxic compounds to the atmosphere have prompted the search for new, alternative energy sources. One of the potential fuels which may be widely used in the future as a fuel is biogas which can be obtained from various types of raw materials. The article presents selected results as regards the effects of the proportion of biogas of various compositions on the course of combustion in a dual-fuel diesel engine with a Common Rail fuel system. The presented study results indicate the possibility for the use of fuels of this type in diesel engines; although changes are necessary in the manner of controlling liquid fuel injection.


2018 ◽  
Vol 44 ◽  
pp. 00003
Author(s):  
Stanisław Anweiler ◽  
Maciej Masiukiewicz

The paper presents research related to the operation of an ground-source heat pump with a thermal output of 16.85 kW and an electrical power of 3.72 kW in various conditions, both from the mechanical and thermodynamic perspective. The publication contains the results of research on a selected heat pump model with an R410a refrigerant carried out in an accredited laboratory in the Czech Republic. Detailed analysis of the data in terms of changes in the COP coefficient for two heating water temperatures was carried out (35°C and 55°C) and in the range of outdoor air temperature from -10°C to 15°C every 1°C. The analysis was also carried out to determine the efficiency of the heat pump depending on the parameters of the heat source. Devices of this type, enabling effective use of environmental available thermal energy with low operating costs, meet increasingly stringent environmental protection requirements. Significant costs of heating buildings are one of the main reasons for the need to look for alternative energy sources. The heat resources contained in water, air and land are huge. Due to the fact that heat pump prices dropped significantly, and their efficiency has increased over the last few years, these devices are a real competition for conventional ways of supplying buildings with heat. Heat pumps do not require daily maintenance, are fully automated and have intuitive control. These features allow to use them as components in the system of a modern and intelligent household. It was shown that the SCOP of the tested device increased by 1% on average reaching SCOP = 4.71 for a typical external calculation temperature and for a low-temperature heating system (35°C).


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