ELEC 4100 POWER SYSTEMS STUDY PROJECT-2022
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ELEC 4100 ELECTRICAL SYSTEMS
POWER SYSTEMS STUDY PROJECT
The objective of this study is to develop a capacity to conduct the analytical studies sufficient to
allow valid and responsible engineering decisions to be made in the context of system planning and
operation. To do this we will study the behaviour of a simple (but representative) 18 bus power
system, as illustrated in figure 1. The various capabilities of the Power World software will provide
sufficient analysis tools for our purpose.
This project is to be conducted on an individual basis.
The study specification provided below is flexible and its intent is to expose students to a realistic
system and to observe and interpret its behaviour, rather than simply obtain results for a prescribed
set of scenarios. Each student may use a different approach to the factors studied.
1. Begin by entering your “Base Case” system as given into Power World. The Base Case
represents the normal high load condition. Examine the power flows and the voltage profile
of the network. All load buses should be within normal system tolerances (i.e. 0.95 p.u –
1.06 p.u.). Use caution when entering the tap-settings for the transformers (e.g. tap 0.95 on
the primary side produces the same effect as tap 1/0.95 on the secondary side).
2. Observe the system behaviour under the condition where any line or transformer is at fault
or taken is out of service. This represents the N-1 contingency test. Are there any lines or
transformers that can not be taken out of service without the system voltages departing from
the acceptable limits (i.e. 0.95 p.u – 1.06 p.u.), or overloading of the remaining transformers
and lines? In particular, are there sections of the network that are marginal? Power World
has a Contingency function which may help. You can tabulate and summarise your results.
3. Define a light load case where the loads are about 40% of those shown. Power World has a
Scale Case function which may be useful here (but please save a copy, since in part 5 you
will return to the base case again). Are there any voltages that are unacceptably high or low
(and why)? Suggest a remedial strategy to compensate for any voltages that are out of spec.
and verify the effectiveness of the strategy (Note: this should not require any additional
capital expenditure, since the light load is a normal situation, which happens every night.
Instead, try to use the regulations that already exist in the system). Discuss the nature and
source of problems associated with a lightly loaded system.
4. For the light load case repeat the N-1 contingency test. How does the system behaviour
compare to the normal (base case) load? Maintenance schedules which require a
transmission line or transformer to be taken out of service are commonly performed at times
where the system is lightly loaded. What capacity does the system have to withstand another
line or transformer tripping with one element already out of service for maintenance? This
represents the N-2 contingency test. Study the N-2 contingency at light load and summarise
your observations.
5. In parts 2, 3 and 4 you have studied the system ability to tolerate the loss of any line or
transformer, under normal and light load. Now suggest a remedial course of action, which
will address the problems identified in parts 2, 3 and 4 (this may include additional
infrastructure). Note that the proposed modifications have to be effective but not overly
expensive. N-1 contingency has to be fully satisfied at normal load and (with additional
regulations) – at light load. N-2 contingency must be “mostly” satisfied at light load, with
some exemptions. For, example, some buses are allowed to be “islanded” (have no power
supply) under N-2 contingency. Discuss why it is ok in some cases. Verify the effectiveness
of the proposed remedial strategy for the same conditions as studied in parts 1, 2, 3 and 4.
ELEC 4100 POWER SYSTEMS STUDY PROJECT-2022
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The result of part 5 is a modified, more secure and resilient, power system. There is no
single “correct answer” to this: each student may have their own solution, as long as it is
sensible and justifiable.
6. Take your modified power system under normal load as the new Base Case. A new
industrial client is to be connected to the system under the new Base Case scenario. The
client has premises located in the vicinity of bus 16 (the distance to the client is
approximately twice that between bus 16 and bus 17), and has an anticipated 33kV demand
of 20MVA at 0.8pf lagging. Plan a connection for the new load with redundancy so that the
client can still be supplied even if one line feeding it is lost. What effect will the new load
have on the system performance? Can the system tolerate the loss of any line or transformer
under the new conditions?
7. Now investigate the anticipated growth of all loads by 50% over the next 10 years, including
the newly connected client. Increase all loads in 10% (or so) steps, up to 150% of the Base
Case, to observe the limiting factors that the load growth will be facing. The purpose of this
exercise is to see what reinforcements and new equipment might be included in the system
development plan, as consumer demand increases over time. Make up your own mind as to
what reinforcements – extra line, bus, or generation – you decide to add. Their addition
should be staged over the next 10 years. Examine the modified system from the viewpoint
of (N-1) security.
8. Develop PV and VQ curves for the newly connected bus 19 (new industrial client).
Determine real and reactive power margins. Discuss potential voltage stability issues, and
suggests ways to avoid or mitigate them.
9. What is typical of real power loss in the system? Choose whatever case you wish, and see
what happens to losses when fixed generation is altered. Move some generation away from
bus 1 to bus 2, or add a generator at a bus elsewhere.
10. Study transient (generator angle) stability for bus 2. Find critical clearing angle, and discuss
how to avoid destabilisation of the power system due to the generator angle deviations.
Your project submission must consist of a report submitted electronically (via Turnitin). You may
be asked to send your PowerWorld files to the Course Coordinator by email as a zip file (as there is
no way to attach a zip file to a Turnitin report).
The report should be kept to 20 pages maximum (font Times New Roman 12 or equivalent, single
line spacing, margins 1.5cm minimum), not including appendices. As you will generate large amounts
of data in this study it is imperative that you devote time to the development of an effective way to
present results. The report should describe the tasks and discuss the results. Tables with brief
summary of the results should appear next to the text to make it easy to refer to. Large tables with
full data generated by PowerWorld should appear in Appendices.
It is insufficient to simply provide simulation results, and poor presentation WILL be penalised.
Treat it as a professional report about the current status and strategic development plan of a power
network that you look after. A good quality discussion, convincing arguments, consideration of
different options and their pros and cons, demonstration of your knowledge about power systems in
general, etc. will give you extra points.
For the mark above 90 points you have to find relevant additional sources of information and
reference them in the report. This additional information may include details on technical solutions
that you propose, costs information, standards, examples of how it is done, etc.
ELEC 4100 POWER SYSTEMS STUDY PROJECT-2022
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Figure 1 : 18 Bus Power System.
Table I : Transformer Tap Settings (Tap on the 2nd Bus)

Bus to Bus	Tap Setting
p.u.
4 – 7	0.98
4 – 9	0.965
5 – 6	0.935

Table II : Static Capacitor Data

Bus	Susceptance
p.u.
6	0.110
9	0.05
18	0.05

Susceptance in p.u. on 100MVA base
ELEC 4100 POWER SYSTEMS STUDY PROJECT-2021
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Table III : Bus Data – Load and Generation, Sbase = 100MVA

Bus	Type	V	V	d	PG	QG	PL	QL	QGmax	QGmin
kV	p.u.	degrees	MW	MVar	MW	MVar	MVar	MVar
1	Swing Bus	132	1.060	0	¾	¾	0	0	¾	¾
2	Voltage Controlled	132	1.040	¾	40	¾	21.7	12.7	50	20
3	Voltage Controlled	132	1.020	¾	0	¾	94.2	19.0	60	0
4	Load	132	¾	¾	0	0	47.8	3.9	¾	¾
5	Load	132	¾	¾	0	0	7.6	1.6	¾	¾
6	Voltage Controlled	33	1.040	¾	0	¾	11.2	7.5	30	6
7	Load	33	¾	¾	0	0	6.2	1.5	¾	¾
8	Voltage Controlled	33	1.060	¾	0	¾	0	0	24	6
9	Load	33	¾	¾	0	0	29.5	16.6	¾	¾
10	Load	33	¾	¾	0	0	9.0	5.8	¾	¾
11	Load	33	¾	¾	0	0	3.5	1.8	¾	¾
12	Load	33	¾	¾	0	0	12.8	5.3	¾	¾
13	Load	33	¾	¾	0	0	13.5	5.8	¾	¾
14	Load	33	¾	¾	0	0	14.9	5.0	¾	¾
15	Load	33	¾	¾	0	0	7.6	2.4	¾	¾
16	Load	33	¾	¾	0	0	4.8	1.2	¾	¾
17	Load	33	¾	¾	0	0	5.3	3.1	¾	¾
18	Load	33	¾	¾	0	0	8.4	3.8	¾	¾

Table IV : Transmission Line and Transformer Impedance Data, Sbase = 100MVA

Bus to Bus	Resistance	Reactance	Line Charging	Maximum MVA
p.u.	p.u.	p.u.	MVA
1 – 2	0.01938	0.05917	0.02640	150
1 – 5	0.05403	0.22304	0.02460	150
2 – 3	0.04699	0.19797	0.02190	150
2 – 4	0.05811	0.17632	0.01870	150
2 – 5	0.05695	0.17388	0.01700	150
3 – 4	0.06701	0.17103	0.01730	150
4 – 5	0.01335	0.04211	0.00640	150
4 – 7	0	0.20912	0	100
4 – 9	0	0.35618	0	100
5 – 6	0	0.25202	0	100
6 – 11	0.09498	0.19890	0	75
6 – 12	0.12291	0.25581	0	75
6 – 13	0.06615	0.13027	0	75
7 – 8	0	0.17615	0	75
7 – 9	0	0.11001	0	75
9 – 10	0.03181	0.08450	0	75
9 – 14	0.12711	0.27038	0	75
9 – 17	0.15621	0.31063	0	75
10 – 11	0.08205	0.19207	0	75
12 – 13	0.22092	0.19988	0	75
12 – 18	0.145	0.350	0	75
13 – 14	0.17093	0.34802	0	75
13 – 15	0.15361	0.26891	0	75
15 – 16	0.18612	0.31654	0	75
16 – 17	0.19564	0.32675	0	75