2. Contents
1. Title
2. Introduction
3. Literature survey
4. Problem definition
5. Objectives
6. Research questions
7. Outcomes
8. Conclusion
9. References
3. 1. Title
Improvement of Voltage Stability in
Low Voltage Networks Containing
Solar PV Distribution Generation
4. 2. Introduction
Previous year installed power
(GW), 2011, 40
Previous year installed power
(GW), 2012, 71
Previous year installed power
(GW), 2013, 100
Previous year installed power
(GW), 2014, 138
Previous year installed power
(GW), 2015, 178
Previous year installed power
(GW), 2016, 229
Previous year installed power
(GW), 2017, 305
Previous year installed power
(GW), 2018, 403
Previous year installed power
(GW), 2019, 501
Previous year installed power
(GW), 2020, 625
Annual addition (GW), 2011, 31
Annual addition (GW), 2012, 29
Annual addition (GW), 2013, 38
Annual addition (GW), 2014,
40
Annual addition (GW), 2015, 51
Annual addition (GW), 2016, 76
Annual addition (GW), 2017, 98
Annual addition (GW), 2018,
98
Annual addition (GW), 2019,
122
Annual addition (GW), 2020,
142
INSTALLED
POWER
(GW)
YEAR
Previous year installed power (GW) Annual addition (GW)
Solar PV global installed capacity (GW) and its annual additions
5. The single line diagram of a LV network with solar PV consists of:
Solar panels as renewable DGs,
Energy storage units such as batteries,
Converters; dc/dc for DC side and dc/ac for AC side,
DC loads
Main grid at point of common coupling (PCC).
7. 3. Literature Survey
UPQC
DVR
SVC
STATCOM
Factors
Higher rating
High rating
Low
Low rating
Rating
Faster
Fast
Less than DVR
Less than DVR
Speed
Series & Shunt
Series
Shunt
Shunt
Compensation
Active and Reactive
Active and Reactive
Reactive
Reactive
Active/ Reactive
Least
Much less
Less
Less
Harmonics
Sag/swell/harmonics
/transient/unbalance/
flicker
Sag/harmonics/fluct
uations/swell
Sag/swell
Sag/swell
PQ issue
Higher
High
Average
Normal
Cost
Higher
High
High
High
Complexity
Comparison between various mitigation devices to Power quality issues
8. 4. Problem definition
Penetration of solar generation units into the main grid,
although economically justified, but it is accompanied by
power quality (PQ) problems. Such issues, as voltage
deviations, flickers, and harmonic distortions in bus
voltage and load current waveforms are major concerns
today. Literature shows that voltage stability problems
(voltage dips and voltage swells) represent about 48% of
total power quality incidences. Voltage level at load buses
in LV grid should be maintained to meet the specifications
listed in PQ standards and satisfy the requirements of
Distribution Generation (DG).
9. 5. Research Objectives
To identify the effect of solar PV DGs on voltage profile
in LV distribution networks.
To specify the role of DG location inside the LV
network, in voltage stability problem.
To model a LV network embedded with solar units in
order to evaluate the voltage stability and improve it.
10. 6. Research Questions
How does DG units affect the voltage stability at
load buses?
Does the location of these units inside LV grid has
any effect on voltage profile of load buses?
What are the optimum mitigation technique that
gives the best voltage stability?
11. Scope of Work
Model a LV network with solar DG using available software package
(PSCAD, ETAP, etc.).
Carry out performance calculation to determine the voltage profile at
load buses.
Perform design configuration assessment with different proposed
locations for the solar DGs.
Use different types of active filters to improve voltage stability.
12. 7. Outcomes
Modeling of proposed LV network is conducted.
Joining various cases aiming to investigate the voltage
sag/swell issue.
Simulation firstly is carried out using the power system
software “ETAP 16”.
Secondly, optimum results are investigated via
conducting different design calculations on the
modelled network.
13. 8. Conclusions
Limitations
Outcomes
PQ issue targeted
Mitigation method
-no standards followed
-I reactive injected for V sag
-supported V stability during faults
V sag
Adapted VSC
control strategy
-no elimination of Q exchange between
DGs
-reduced VHF to ≤ 1%
-reduced THD V&I to ≤ 5%
Harmonics & V
unbalance
DVR 1
-high cost & more complexity
-V sag mitigation at different faults
V sag
DVR2
-more system complexity
-V fluctuations & deviations are eliminated
V fluctuations
STATCOM
- high cost & more complexity
-reduced harmonics comply with IEEE 1547
standard
Harmonics
DSTATCOM
-poor performance
-V sag eliminated by Q injection during the
event
V sag
SVC
- high cost & more complexity
-reduced V&I harmonics comply with IEEE
standards
Harmonics V&I
UPQC
Comparative methods of PQ issues & mitigation techniques in LV networks
14. Time Schedule
Description
Task
Phase
Study of current research in existing MGs with solar PV-based distribution
generation.
Topic Definition
1
Collect data from literature survey related to PQ issues and its mitigation
methods for solar-based DGs in LV distribution grids.
Literature Survey
2
The literature review is demonstrated and discussed to specify the gap in
literature.
Definition of gap in
literature review
3
The simulation of the designed system of LV grid containing solar-based
DG is carried via adequate computer software.
Modelling
4
Evaluation of bus voltages through calculations conducted for various
scenarios with different locations for solar DG in the LV grid.
Performance calculations
and Validations
5
Final thesis report writing and preparation.
Thesis
6
Research phases definition
16. 9. References
[1] Ammar A. Alkahtani, Saad T. Y. Alfalahi, Abedalgany A. Athamneh, Ali Q. Al-Shetwi, Muhamad Bin Mansor, M.
A. Hannan, Vassilios G. Agelidis, "Power Quality in Microgrids Including Supraharmonics: Issues, Standards, and
Mitigations", IEEE ACCESS, Volume 8, pp. 127104 - 127122, July 2020.
[2] A. Novitskiy, S. Schlegel, D. Westermann, " Measurements and analysis of supraharmonic influences in a
MV/LV network containing renewable energy sources", 2019 Electric Power Quality and Supply Reliability
Conference and 2019 Symposium on Electrical Engineering and Mechatronics, PQ and SEEM 2019.
[3] D. Amaripadath, R. Roche, L. Joseph-Auguste, D. Istrate, D. Fortune, J.P. Braun4, F. Gao, "Power Quality
Disturbances on Smart Grids: Overview and Grid Measurement Configurations", 2017, 52nd International Universities
Power Engineering Conference (UPEC), 2017.
[4] Renewable Energy World Editors, "142 GW of global solar capacity will be added in 2020, says HIS", online
article, https://www.renewableenergyworld.com/2020/01/10/142-gw-of-solar-capacity-will-be-added-to-the-global-
market-in-2020-says-ihs/
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International Journal of Enterprise Network Management, Volume 8, Issue 4, 2017.
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[11] T. Sridevi and Y. Suri Babu, “Mitigation of voltage sag and swell in a Grid connected PV system by using Dynamic
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[12] Rahul G. Suryavanshi and Irana Korachagaon, “A review on power quality issues due to high penetration level of solar
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[15] Sachin Devassy and Bhim Singh, “Design and Performance Analysis of Three-Phase Solar PV Integrated UPQC”,
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