design a micro grid
Microsoft Word - Assignment RESI (2021).doc 1 M S c A ssignment2021 Renewable E nergyS ystems Integration (RE S I) Instru ctions Marks: 50% of the module total marks. Due date and time: on Friday 26th March 2021 at 2 pm Each student is required to submit an individual and formal report. The problem has no unique approach/ solution and therefore the methods/ solutions are expected to be varying from one student to another. Students may make best possible assumptions if any extra information is required, however, they should be justified in a Micro Grid context, giving relevant reasons with appropriate references. Submission will be via Canvas, please familiarise yourself with Canvas before submissions are due. Files are to be smaller than 20MB to be able to submit to the Canvas. Maximum number of pages in your report, excluding the cover page, must not be more than 15 (Including appendices). Minimum font size of the body of the report should be 11. Font size of the captions of figures and tables must be 10. The file type must be PDF. Late submissions will be penalised by deducting 5% marks per day late. Assignments will not be accepted more than 20 days late after the submission deadline. A cademic Integrity Plagiarism will not be tolerated. It is the act of a Student claiming as their own, intentionally or by omission, work which was not done by that Student. Plagiarism also includes a Student deliberately claiming to have done work submitted by the Student for assessment which was never undertaken by that Student, including self-plagiarism and the other breaches. Sanctions of a plagiarism include the Student failing the Programme of study. 2 P roblem S tatement Figure 1 shows a schematic diagram of a micro-grid model. The micro-grid must supply its own electricity demand using Wind, PV, and diesel power generation. Suitable energy storage technologies including electric vehicles and/ or batteries can be used to support any energy shortage in the micro- grid system. Diesel power generating units are also available to provide standing reserve in the events of any significant need of the micro grid system. The micro-grid should be designed in such a way that it facilitates the grid connected and islanded modes of operation while respecting the economic stability, security, and efficiency of micro grid system. One of the design objectives of the micro-grid is to use renewable power generation at most of the operating conditions and then to use minimum level of fossil fuelled power generation. However, the energy and energy supply security of the micro grid should not be compromised with the maximum use of renewable power generation, unless otherwise micro grid loads are flexible. The micro grid design should also consider potential electricity demand growth at 10th and 20thyear time horizons. You should find typical demand growth at 10- and 20-year cycles through the publishes articles/ reports at a particular location. The micro-grid has six load centres which are represented as buses 3, 4, 5, 6, 7 and 8. The technical data of the electricity demands of consumers are given in Table 1. It is given that 50%, 60%, and 80% of loads respectively connected at buses 4, 5, and 7 are critical loads. A number of fixed speed wind turbine units are installed at buses 3, 5 and 8 to supply the local demand in conjunction with diesel units. Diesel units can be installed as a central generation by locating at a single bus or dispersed generation by locating units at distributed buses. Each wind turbine unit is rated at 66 kW and a number of units can be connected to a bus as per the technical specification of the micro grid system. The wind turbine units should be installed considering the technical and economic benefits of the micro grid. The loads connected at buses 6 and 8 represent residential and commercial loads and it is also proposed to install a number of 5 kW rated PV modules at these buses to supply 40% of the active power load demand at Bus 6 and 8. Table 2 shows the feeder technical data which can be used to determine the sizes of feeders that are suitable for the micro-grid. Micro-grid feeders are to be designed to carry at least 120% of excess loading from the peak loading at any operating condition at any time. Table 3 gives the average loads of each bus in a sample day considering the daily average of the corresponding month, normalised wind power output, and peak sun hours in the sample day. Wind power output is normalised by dividing the actual power output of the wind plant by its installed capacity. The diesel units can be selected from a pool of n1 #30kW, n2 #60kW, n3 #150kW, and n4 #250kW , where 4321 and,,, nnnn represent any number of diesel generators that are suitable for the micro grid specification. (1)Describe the design and operating strategies that you would implement to the micro grid to benefit micro grid system owner and operator considering climate change and global warming effects and technical and economic perspectives. Note that the remaining parts of the assignment should be driven 3 through your proposed strategy in this part considering the given specifications of the assignment and any extra thoughts adopted to further develop the specification considering a realistic busines case. [10] (2)Draw a complete schematic diagram showing the detailed component connections of wind, PV, diesel, and others that are needed to operate the micro-grid system smoothly in real-time by expanding/ extending Figure 1. Also describe how each component/system in the expanded/ extended micro grid system operates considering operating functions of each key element of the micro grid system. [10] (3) Calculate the number of (a) wind turbine units and (b) PV modules required to meet the demand of the micro-grid as per the given specification in the assignment and the design & operating strategies proposed in part (1). (c) Determine the number of diesel units, their sizes, and their locations in the micro-grid. (d) Size the micro grid feeders using the given technical and costing data to meet the loading and other conditions of the proposal. (e) Use energy storage solutions as needed and size them justifying technical and economic benefits. (f) Size capacitor banks for the micro grid system to compensate for reactive power demands at loads. Consider the efficiency of a PV system as 64%. Assume that there are no shading effects. Also, consider that the power losses of a feeder can be approximated to 2.5% of the electricity demand through the respective feeder. Show all the calculation details, assumptions, and technical and economical justifications as appropriate. [60] (4)Present a formal report covering (1) to (3) sections, presenting the engineering judgements you made, a discussion, conclusion, and references. The arguments, discussions, and conclusions must be made by referring to the given case of the assignment. No marks will be given if a student just reproduces conclusions, discussions, or justifications that are commonly available in published literature or textbooks. [20] Students are allowed make reasonable and realistic assumptions; however, they should be technically feasible and economically justified. Students may use online (or published) technical data apart from the data given in the assignment; however, the sources of information should be given as references. The marker will only mark what is in the body of the report and not the contents in the appendices. Long tables of data such as Excel tables should be placed in appendices. Table 1: Load data Bus number Peak load (MVA) Power factor 3 0.55 0.82 4 0.82 0.88 5 1.24 0.85 6 0.44 0.87 7 0.61 0.86 8 0.46 0.88 4 Table 2: Feeder technical data Given identifications of feeder sizes R (Ω /km) X (Ω /km) Capacity (kVA) Price (£/MVA/km) S1 0.25 0.13 120 152,000 S2 0.18 0.13 140 152,000 S3 0.13 0.1 160 152,000 S4 0.07 0.1 230 152,000 S5 0.05 0.1 300 152,000 Table 3: load demand and generation data Sample day Demand at each load bus in % of peak connected load Normalised output of wind power generation Peak sun hours in the sample day 1 92 0.36 4.22 2 96 0.32 3.33 3 85 0.38 3.32 4 88 0.22 5.38 5 95 0.34 4.54 6 98 0.28 5.85 7 100 0.30 5.88 8 95 0.32 5.80 9 90 0.32 3.86 10 92 0.36 3.24 11 90 0.34 4.42 12 95 0.33 2.12 3-ph, 0.55 MVA PF = 0.82 3-ph, 0.82 MVA PF = 0.88 3 42 1 Utility grid connection l=0.94 kml=0.62 km 3-ph, 12.0 MVA, 11 kV/415 V l=1.0 km 1-ph, 0.44 MVA PF = 0.87 3-ph, 0.61 MVA PF = 0.86 6 7 3ph, 1.24 MVA PF = 0.85 5 1-ph,0.46 MVA PF = 0.88 Micro Grid l=0.35 km 8 Figure 1: l = length of the feeder, PF = power factor, an arrow indicates electricity demands of consumers