联系我们： 手动添加方式: 微信>添加朋友>企业微信联系人>13262280223 或者 QQ: 1483266981

MSc Assignment 2023
Renewable Energy Systems Integration (RESI)
Instructions
Marks: 50% of the module total mark.
Due date and time: on Thursday 30th March 2023 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/ Prosumer 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.
2000 word-limit report must not be more than 15 pages, excluding the cover page. 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 of the report must be PDF. Please use IEEE referencing style.
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.
Academic 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.
If concerns are raised about your work then you may need to participate in a viva (oral examination) of
your work.
By Dr D. Jayaweera
Problem Statement
Figure 1 shows a schematic diagram of a micro-grid model with specified wind and solar resource
areas. The micro-grid has to supply its own electricity demand using Wind, PV (Photovoltaic), energy
storage solutions and minimum level of diesel power generation.
The micro-grid is aimed at operating in the grid-connected and islanded modes as per the
operational needs. One of the key objectives of the micro-grid design is to maximise the use of
renewable power generation. However, the energy security of the micro grid should not be
compromised with the maximum use of renewable power generation, unless otherwise micro-grid loads
are specified as flexible and a proper business case is justified. The micro-grid design should consider a
potential load growth of 0.75% of peak load per year in the first 10 year operating time horizon and
1.5% of peak load per year in the rest of the operating horizon. Further, all renewable power generating
systems should be considered as de-rates at 1.25% per year from their installed capacities after ten
years of operation.
The micro-grid has six load centres at buses 3, 4, 5, 6, 7, and 8. The bus 6 electricity
consumers are entirely operating as prosumers. Its power demand varies within 30% to 100% of peak
load due to the prosumer actions every day. The prosumers at bus 6 generate electricity using PVs and
energy storage. The technical data of the peak load demand of the prosumers at bus 6 and consumers at
rest of the load buses are given in Table 1. It is given that 10% and 30% of loads respectively
connected at buses 4 and 5 are critical loads. A number of fixed speed wind turbine generators (WTG)
are installed at bus 3 to supply 100% of local electricity demand of the bus . Diesel units can be
installed as a central power generation by locating them at a single bus in the micro grid or dispersed
power generation by locating them at multiple sites (buses) in the micro grid. Rated power of each
WTG proposed for the micro grid is 60kW. A number of wind turbine units can be installed at a bus as
per the wind-resource availability. The WTGs should be installed considering the technical and
economic benefits and operating constraints of the micro grid. It is also proposed to install a number of
6 kW rated PV modules at bus 7, and 8 to supply 40% of the peak active power demand of these buses
with the supports of energy storage solutions.
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 160% of
excess loading from the peak load at any operating condition in the operating horizon of the micro grid.
Table 3 gives the average loads of each bus in a characteristic day that is representative of the daily
load of the corresponding month, normalised wind power output, and peak sun hours in the
characteristic day. Wind power output is normalised by dividing the actual power output of the wind
plant by its installed capacity. The characteristic day number represents the month of the year. The
diesel units can be selected from a pool of n1 # 10 kW, n2 # 30 kW, n3 # 100 kW , where
n1
,n2
, and n3
represent any number of diesel generators that are suitable for the micro grid
specification. The diesel generators should not be operated below 20% of their capacities to limit in_xfffe_efficient operating conditions of them.
By Dr D. Jayaweera
By Dr D. Jayaweera
(1) Describe the design and operating strategies that you would propose to implement for the micro
grid specification above to benefit micro grid system owner/ operator, electricity consumer and
prosumers. [10] Marks
(2) Considering the problem statement given above and your design and operating strategy:
(a) Calculate the number of WTGs supplying the specified demand of the micro-grid
(b) Calculate the number of PV modules supplying the specified demand of the micro-grid
(c) Determine the number of diesel units, their ratings, and their locations appropriate to the micro grid design and calculations presented in 2(a) and 2(b).
(d) Determine the sizes the micro grid feeders using the given technical and costing data to meet the
system conditions of the proposal.
(e) Determine ratings and locations of energy storage solutions.
(f) Determine the ratings and locations of capacitor banks for the micro grid to compensate for
reactive power demands at loads.
In your calculation, consider that the efficiency of the PV system is 64% and the effect of shading is
negligible. You have the option to simplify the calculations by ignoring the electrical power loses of
the power transfer system. Show all the details of the calculation, assumptions, and technical and
economic justifications where possible. Repetitive calculations can be presented/ tabulated in an
appendix in your report. [55] Marks
(3) Calculate Life Cycle Cost (LCC) of the micro grid and justify the technical and economic feasibility
of the micro grid design and operation. [15 Marks]
(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 students just
reproduce conclusions, discussions, or justifications that are commonly available in published
literature. [20] Marks
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 1.5 0.86
4 0.60 0.85
5 0.82 0.92
6 0.8 0.92
By Dr D. Jayaweera
7 0.65 0.88
8 0.75 0.92
Table 2: Feeder technical data
Given
identifications of
feeder sizes
R (Ω/km) X (Ω /km) Capacity (kVA) Price
(￡/MVA/km)
S1 0.25 0.13 120 192,000
S2 0.18 0.13 140 192,000
S3 0.13 0.1 160 192,000
S4 0.07 0.1 230 192,000
S5 0.05 0.1 300 192,000
Table 3: Load demand and generation data
Characteristic
day
Demand at each load bus
in % of peak connected
load
Normalised output of
wind power generation
Peak sun hours in the
characteristic day
1 72 0.28 4.88
2 86 0.22 4.9
3 72 0.28 5.2
4 94 0.32 4.7
5 85 0.34 5.5
6 100 0.26 5.8
7 98 0.35 5.0
8 95 0.31 4.8
9 90 0.28 4.2
10 85 0.34 4.62
11 90 0.30 5.2
12 95 0.34 4.4
0.8MVA
PF=0.92
1.5MVA
PF= 0.86
Bus 6 Bus 3 Bus 2
Bus1
Utility Power
l=2km l=2.5km
12.0MVA,
11kV/415V
0.65MVA
PF=0.88
Bus 7
0.75MVA
PF=0.92
Bus 8
0.6MVA
PF=0.85
Bus 4
0.82MVA
PF=0.92
Bus 5
l=0.4km
l=0.75km
l=0.6km
Solar resource area Wind resource area
Double line
Figure 1: l = length of the feeder, PF = power factor, an arrow indicates load demands of consumers