辅导案例-ELEC3105

  • August 1, 2020

ELEC3105: Electrical Energy Assignment: T2, 2020 Total marks: 35 Information sheet: This assignment will contribute 13% toward your final marks. The last day of submitting the assignment is 5 pm, Tuesday, 11 August (Week 11) via Assignment link in the Moodle. The assignment must be uploaded to the Moodle system as a pdf file. Late submission will not be permitted under any circumstances; submission via email attachment will also not be considered once the deadline expires. Since this assignment counts towards your formal assessment for this subject, you are required to sign a declaration and attach this cover sheet to the front of your submission. Without this signed declaration, the assignment will not be considered for assessment. A fillable pdf file for signed declaration is included with the other documents. Note that plagiarism (i.e. copying of assignment or pay someone to do your assignment) is an academic offence. If suspected of plagiarism, you may be referred to disciplinary board and will be subjected to heavy penalties. Check https://student.unsw.edu.au/plagiarism for detailed information. What is being assessed by this assignment? The purpose of this assignment is to assess the following learning outcomes and graduate attributes: Learning outcome: • Be capable of selecting, and designing some important power engineering devices for real- life applications, • Be able to apply underlying theories and concepts in the design process. Graduate attributes: 1. Analytical skills, critical thinking and creative problem solving. 2. Demonstration of the understanding of principles. 3. Effective use and communication of relevant information. Feedback Rubric/marking criteria: The marks related to each part of the question are shown next to it. Percentage distribution of the total mark of each part is according to the 4 marking criteria given in the table. This table will also serve as the feedback rubric once you have received your score. Score <50% 50-64% 65-74% 75-84% 85-100% Criteria Application of under lying theories and concepts. 40% Student does not have grasp of information; student cannot answer questions about subject. Student demonstrates sound knowledge by giving expected answers to most, but not all questions. Student demonstrates good knowledge by giving expected answers to all questions, but fails to elaborate. Student demonstrates full knowledge by answering all questions with explanations and elaboration. Student demonstrates full knowledge (more than required) by answering all questions with explanations and elaboration. Interpreting findings from solving the problems and plots. 30% Student does not interpret the findings/reach a conclusion. Student provides an inadequate interpretation of the findings and does not derive a logical solution to the problem. Student provides an adequate interpretation of the findings and solves some of the problem, but not all. Student provides an adequate interpretation of the findings and solves the problem, but fails to provide alternatives. Student provides a logical interpretation of the findings and clearly solves the problem, offering alternative solutions. Identifies and assesses assumptions, conclusions, implications and consequences. 20% Fails to identify conclusions, implications, and consequences of the issue or the key relationships between the other elements of the problem, such as context, implications, assumptions, or data and evidence. Identifies some of the conclusions, implications, and consequences of the issue or the key relationships between the other elements of the problem, such as context, implications, assumptions, or data and evidence. Identifies and discusses some of the conclusions, implications, and consequences considering context, assumptions, data, and evidence. Identifies and discusses conclusions, implications, and consequences considering context, assumptions, data, and evidence. Identifies and discusses conclusions, implications, and consequences considering context, assumptions, data, and evidence. Objectively reflects upon their own assertions. Neat and clear presentation of data and information. 10% Illegible and unclear presentation and information. Somewhat clear and neat presentation. Clear and neat presentation of data but with room for improvement. Clear and neat presentation of data. Data and information are presented with professional clarity and neatness. Total Marks: 35 Tasks: You are a lead engineer at a reputed energy consultancy firm. Your firm has won a contract to investigate ‘deployment of rooftop solar (photovoltaic) and wind energy for a large building at UNSW Kensington campus’. The firm’s management has given you the task of fact-finding. You are required to produce a short technical report for the management based on your findings. The report must find answers/solutions to the following questions/problems: Question 1: Solar Energy [10 marks] (i) [2 marks] Find a building with the most suitable rooftop area. Estimate the available roof area for installing the photovoltaic panel. You can use the software tool Nearmap.com to assess the building rooftops. (How to access Nearmap.com – Go to UNSW Library website> search for Nearmap. In the search result, select Nearmap under database category. Once you click the link, it will ask you to register as a UNSW user. You will receive an instruction email to activate your UNSW account). (ii) [1 marks] Find the average power and energy consumption for the building of your choice from (i). You can use the link below to check energy consumption and average power of a building at UNSW Kensington campus : https://www.sustainability.unsw.edu.au/our-plan/energy-and-water-efficiency/kensington- campus-live-energy-consumption (iii) [3 marks] A datasheet of a commercial photovoltaic module was provided in the pdf file: (Origin1500_Panel_Specifications.pdf). Use this data to estimate how many panels you will require to supply the average power of (ii)? Can you fit all the panels on the available roof area found in (i)? If not, what is the power that can be provided by fitting the maximum possible solar panels in the available roof area? (iv) [2 marks] How much annual energy saving is possible if the rooftop area is fully utilized using the panels? To answer this question, you should consider the average irradiance and temperature of the Kensington area and consult the panel specifications. (v) [2 marks] How many panels need to be connected in series and parallel if the required output voltage is 240V(DC) and power is the same as found in (ii). Question 2: Wind Energy[25 marks] In the discussion forum of ELEC 3105, many of you have concluded that a VAWT (Vertical Axis Wind Turbine) can be used as an alternative to rooftop solar in the urban area. In this task, you will investigate the feasibility of VAWTs for the UNSW Kensington campus. (i) [2 marks] Use an internet search to find the average wind speed and air density for the Kensington campus. Then calculate the power density (W/m3) of the area. (ii) [6 marks] A VAWT turbine is used with a 3-phase, 4-pole, Y-connected, 300V (line), 50Hz. Induction Generator for wind energy conversion. Equivalent circuit parameters of the generator were found from experimental tests: R1= 1. 54Ω/ph, R2= 3 Ω/ph, X1=X2=5 Ω/ph and Xm = 58 Ω/ph. Constant rotational losses were 200W. There is a mechanism of slip control for the generator. The slip can be varied from 0 to -0.45 in steps. Find the output power of the generator for the step variation of slip. Present the result as a plot between output power versus generator speed in rpm. (iii) [4 marks] Calculate the range of efficiency for the generator for the same slip variation of (iii). Plot the efficiency versus slip for the generator. (iv) [2 marks] Using the efficiency versus slip plot of (iii), find the slip and the generator speed at which the maximum efficiency occurs. These values will be considered as the rated slip and speed of the generator. (v) [2 marks] Record the value of the maximum efficiency and the output power at this efficiency. These values will be considered as the rated power and efficiency of the generator. (vi) [2 marks] Data of the VAWT turbine is provided in a pdf file (Vertical Axis Wind Turbine Specifications_assignment2020.pdf). If the generator speed and slip are fixed at their rated values, find the required gear ratio for cut-in-wind speed, cut-out-wind speed, rated-wind-speed and average wind speed of UNSW Kensington campus. (vii) [2 marks] Is the rooftop area that you have chosen for Question 1 also suitable to install VAWTs? If not, you may look for other suitable buildings using Nearmap. Once a building is identified, find the average power using the same link as in Question 1 (ii). (viii) [5 marks] Considering the rated output power of the induction generator from (v), estimate how many VAWTs will be required to supply the average power for the chosen building. Is it feasible? Why or why not? How many VAWTs can be practically installed on the rooftop of the building? How much annual energy saving is possible using these installations? Is it comparable to the energy saving of Q1(iv)? Make comments. End of the assignment

LATEST POSTS
MOST POPULAR

ezAce多年来为广大留学生提供定制写作、留学文书定制、语法润色以及网课代修等服务,超过200位指导老师为您提供24小时不间断地服务。