Advances in Science, Technology and Engineering Systems Journal Vol. 6, No.

2, 324-331 (2021)
ASTESJ
www.astesj.com
ISSN: 2415-6698

Investigation of the Impact of Distributed Generation on Power System Protection

Ayoade F. Agbetuyi1, Owolabi Bango1, Ademola Abdulkareem1, Ayokunle Awelewa1, Tobiloba Somefun*,1, Akinola Olubunmi2,
Agbetuyi Oluranti3
1
Department of Electrical and Information Engineering, Covenant University, Ota, 112107, Nigeria
2
Department of Electrical and Electronics Engineering, Federal University of Agriculture Abeokuta, Nigeria
3
Department of Physics, Ekiti State University, Ado Ekiti, Nigeria

ARTICLE INFO ABSTRACT

Article history: Integration of Distributed Generation (DG) on distribution networks has a positive impact
Received: 18 November, 2020 which includes the following: low power losses, improved utility system reliability and
Accepted: 24 January, 2021 voltage improvement at buses. A real distribution network is radial in which energy flow is
Online: 17 March, 2021 unidirectional from generation to transmission and from distribution to the load. However,
when a DG is connected to it, the power flow becomes bidirectional, and the protection
Keywords:
setting of the network may be affected. Therefore, the aim of this research work is to
Power system
investigate the impact of distributed generation DG on power system protection. The test
Protection relay
distribution network is first subjected to load flow analysis to determine its healthiness with
Distributed generators
and without DG connection. The load flow results confirm that the integration of the DG
Distribution network
into the distribution network reduces the active power load loss by 92.68% and improves
voltage profiles at each bus of the network by 90.72%. Thereafter, the impact of DG on the
protection setting of the existing test network was investigated. Integrating DGs to the
network, from our result, shows an increase in the fault currents, which in turn caused false
tripping, nuisance tripping, and blinding of protection relay compared with when DGs are
not connected. The protection relays were reset at the point of common coupling (PCC) to
prevent any abnormal tripping. This is the major contribution of the research work.

1. Introduction by which the generator is interfaced with the network and the
location of the connected DG [3, 4], just as in the case of capacitor
Integration of distributed generation (DG) into the distribution and or phase measurement unit (PMU) placement. The steady-
systems offers many advantages and disadvantages to the state behaviour of the network describes the healthiness of
distribution network [1, 2]. Economic and environmental benefits, distribution network before and after the integration of the DG.
and increased penetration of DGs, will impose significant technical This is carried out by load flow analysis on the network, while the
barriers on the efficient and effective operation of the distribution transient behaviour of the network has to do with the stability and
systems. Increase in fault current and changes of power flow from the setting of the protection relay [3] which is a major concern in
unidirectional to bi-directional are the major two impacts of DG this research work. Among all other challenges affecting the
on the distribution networks, and these affect the existing integration of DG into the distribution networks, protection issues
protection of the distribution system relay, especially the over- are considered one of the major concerns because they are directly
current relays. Therefore, the impacts of DGs on the existing related to the system's safety and reliability.
distribution system must be thoroughly investigated in order to
ensure the stability and reliability of the system. The integration of DG has positive and negative impacts on the distribution
DG into the distribution network has a great impact on the steady- networks. DG positive impacts are as follows, improved the
state and transient behaviour of the network which depends on the voltage profile, improved power quality, and reduces the power
DG capacity and penetration levels, type of generator, the method losses in the distribution network; it eliminates the additional
*
Corresponding Author: Tobiloba Somefun, Email:
transmission and distribution capacity and improved reliability of
tobi.shomefun@covenantuniversity.edu.ng the system [5, 6] among others. The negative impacts include lack
www.astesj.com 324
https://dx.doi.org/10.25046/aj060237
 A.F. Agbetuyi et al. / Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 2, 324-331 (2021)
of safety of the public and utility personnel, damage to the plant in In this research work, the load flow analysis of the test
the event of unsynchronized reclosure protection performance distribution network is first analyzed using Neplan software to
degradation, etc. [7, 8]. The integration of DGs makes the confirm the distribution network's healthiness before and after the
distribution network no longer operate as a passive system but now integration of DG. This is because an unhealthy distribution
operates as bidirectional power flow which may affect the network network will be much more affected negatively with DG
protection. This could lead to lack of relay coordination among the integration. Many of the authors above failed to do this. Also, a
different protection schemes of the system [9, 10]. Therefore, the real distribution network is used for this investigation and not test
traditional protection schemes used in the distribution system need distribution network. The DG penetration level into the
to be re-evaluated or reset with the integration of DG. However, distribution network is analyzed and with the relay tripping time.
before the protection issues are considered, it is very necessary to The maximum DG penetration level in each bus that will not give
ascertain the healthiness of the existing distribution network with rise to protection miscoordination is analyzed.
and without DG connection. Emphasizes here are on the power
3. Materials and Methods
losses and voltage profile at each bus.
2. Literature Review The distribution system is modelled using Neplan software.
The grid components parameters are collected from Eko
This section provides a critical review of the relevant literature Electricity Distribution Company which include the transmission
that is related to the study. The impact of DG on short circuit line, number of buses, transformers and load information. The
current flowing in the network depends on the location, capacity essence of load flow study is to investigate the voltage profile on
and the type of bus to which the DG is connected. Utilities are no each bus, the real and reactive power load loss in the network. The
longer embarking on building large generating plants. Distributed load flow analysis was designed to assess the steady-state
generator serves as an alternative for generating energy resources performance of the distribution network under no-fault conditions.
[11]. There are many benefits of DG integration, but the The load flow analysis was carried out on the distribution network
penetration of DG into the distribution network may cause with or without distributed generation connected to it. The
protection issues in the existing distribution network because it is distribution network was modelled for protection relay
designed to operate as a radial network. The major challenges that coordination with Neplan software. Simulation of the entire
are related to power system protection as a result of the integration distribution system was done to investigate the effect of the
of DGs according to reference [12] include the following: blinding, penetration level of DG on distribution system protection. The
false tripping of feeders, nuisance tripping of protection schemes, single line diagram of the modelled distribution network is as
unintentional islanding, increasing of fault levels, neutral shifting, shown in Figure 1.
resonance, automatic recloser out of synchronism.
False tripping and islanding operations were prevented via
proper coordination of the protection relay with high penetration
of DG into the distribution network according to the investigation
by authors in references [9,13]. Also, [14] researched the effect of
protection and fault current on high penetration of DG with the
distribution system. His result showed that the penetration of DG
in the distribution increased the fault current in the system. Author
[15] also worked on the DG imposed technical barriers for
effective and efficient operation on distribution network with fast
reclosure, his result revealed that fault current increased with the
capacity and penetration level of the DG connected to the
distribution network. Authors in [16] also investigated the relay
protection coordination in the presence of high penetration of DG
with the distribution system, and he concluded that the penetration
Figure 1: Single line diagram of the modelled distribution network
of DG affects the protection of the existing distribution network
which required resetting of the protection relays. Authors in 3.1. Description of Berkeley and Fowler Injection substations is
reference [17] worked on reducing the fault current and improving used as the test distribution network
the quality of power system reliability with Solid State Fault
Limiter (SSFL) to replace substation equipment he concluded that From the single line diagram of the test distribution network in
the protection system of DG with SSFL is preferable to compare Figure 1, the distribution network is being fed from Transmission
to without SSFL. Author in reference [18] analyzed the relay Company of Nigeria (TCN) grid. The real power and reactive
coordination challenges in the presence of DG with different types power are 17.362MW and 0.308MVar connected to 33kV bus1,
of DGs and its capacity using Fault Current Limiter FCL series three 33kV lines radiated from TCN are Berkeley, 33kV single line
reactance, and he concluded that the fault current on synchronous and Fowler 1&2, 33kV line double circuit with 3km and 5km
generators (SG) is more pronounced compared with other DG such respectively. Festac1, 33Kv line feeds Berkeley Injection
as doubly-fed Induction Generator (DFIG). He stated that the substation via 33kV bus2, the primary of 15MVA power
protection relay coordination's integrity could be more preserved transformer is connected to bus2 while the secondary side is
using series reactance fault current limiter. connected to 11kV load bus4 with 8.3MW load. The units of
hybrid generators (wind plus diesel) turbine DGs with the rating of
www.astesj.com 325
 A.F. Agbetuyi et al. / Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 2, 324-331 (2021)
22MW is connected to bus4 by 11kV double line circuit via bus6 4. DG Penetration at Berkeley (buses 4,6&8) Injection
with a power transformer and 0.415kV bus8. Fowler 1&2, 33kV Substations
line double circuit feeds Fowler 15MVA Injection substation via
33kV bus3, the primary side of the power transformer is connected The effect of distributed generation can be analyzed by
to bus3 while the secondary side is connected to 11kV load bus5 connecting the generators to the load buses one after the other and
with 9MW load. Interconnector line is connected to the bus2 and confirming their simultaneous effect on the system [20].
bus3 for flexibility of the network. The line impedance of the Traditionally the power flow in the distribution system is
distribution network used for this research is R = 0.101 and X = unidirectional without distributed generation, but the integration of
j0.077, data collected from the utility company. From this, it can Distributed Generation makes the energy flow bi-directional,
be seen that R/X Ratio is 1.311688, which is high compare to the causing loss of relay coordination in the systems. The technical
transmission network, which is always less than 1. Also the challenges between DG and protection schemes are the increase in
conventional load flow analysis will not converge for the short circuit fault currents, lack of relay coordination in the
distribution network because of the high R/X Ratio [19]. Hence protection system, failure to the closure of line after the occurrence
NEPLAN software is used to carry out the load flow analysis of of a fault in the networks, effect of islanding and untimely tripping
this study. of DG interface on the protection systems of the distribution
systems.
3.2. Results of Load-flow on the test distribution network
The impact of penetration level of the DG on the distribution
The result of power loss with and without DG attached to 11Kv network cause protection miscoordination which can be analyzed
bus in Berkeley injection substation is shown in Table 1 while as follows, the Distributed Generation Penetration Factor (DPF)
Table2shows the voltage profile of the system with and without and is plotted against the Protection Mis-coordination Index (PMI)
DG connected to the distribution network. Figure 2 gives the [21].
graphical representation of voltage profile with and without DG.
DGconnectedtoBus (MW)
Table 1: Result of power loss without and with DG DPF = (1)
SystemLoad (MW)
Substation Active Reactive 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒
S/N Load Power load Power load Status PMI = (2)
𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒
(MW) loss (Mw) loss (Mvar)
5. Results and Discussion
1 8.3 0.123 1.111 without DG
2 8.3 0.009 0.007 with DG 5.1. Simulation by Penetration of DG at bus 4 of Berkeley
Injection Substation

Figures 3 and 4 show the single line diagram of three-phase

fault simulated without and with DGs connected respectively. The
penetration level of DGs into the test distribution network is done
by simulation of three-phase fault using Neplan software to
confirm the level at which the penetration of DGs affects the
distribution network's protection system. Table 3 shows the
simulation result of fault current and time of tripping without DGs
connected. Also, it can be observed from the result of the
simulation in Table 4 that as the capacity of the penetration level
of DGs increases, the fault current likewise increases while the
tripping time of the relay protection decreases. This is to confirm
Figure 2: graphical representation of the voltage profile of with or without DG that the integration of DG into the distribution network causes an
Table 2: The voltage profile of the system with and without DG increase of the fault current in the distribution network, compare
with what is seen in Table 3 when DG is not connected.
Nominal Bus Per
S/ Table 3: The simulation result of fault current and time of tripping without DGs
BUS voltage voltage Unit Status
N connected
(Kv) (Kv) (p.u)
1 4 11 10.269 0.934 Fault Current Time
Bus
(IKA) (s)
2 2 33 32.922 0.998 without
DG 1 0.962 1.66
3 7 33 32.999 0.999
2 0.962 0.259
4 4 11 10.986 0.999
with 4 2.887 0.129
5 6 11 10.988 0.999
DG
6 8 0.415 0.415 1

www.astesj.com 326
 A.F. Agbetuyi et al. / Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 2, 324-331 (2021)

Figure 3: Single line diagram of the test distribution network simulated without DGs connected

Figure 4: single line diagram of three-phase fault simulated with DGs connected
Table 4: The simulation result of the DG penetration level, fault current (kA), and protection miscoordination time (PMT)

DG Penetration (MW) Fault Current (KA) PM Time (s) Remarks

0.255 3.323 3.269

0.425 5.378 1.194 Miscoordination of relay, blinding and false
0.595 7.227 6.984 tripping
0.765 8.839 32.572
www.astesj.com 327
 A.F. Agbetuyi et al. / Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 2, 324-331 (2021)
0.935 10.214 6.798
1.105 11.369 4.288
1.275 12.331 3.296
1.445 13.129 2.85
1.615 13.791 2.542
1.785 14.342 2.353
1.955 14.801 2.229
2.125 15.187 2.132
2.295 15.512 2.056
2.465 15.788 1.994
2.635 16.023 1.944
2.805 16.226 1.891
2.975 16.4 1.891
3.145 16.551 1.849
3.315 16.683 1.829
3.485 16.799 1.812
3.655 16.901 1.797
3.825 16.992 1.784
3.995 17.072 1.772
4.165 17.143 1.762
4.335 17.207 1.753
4.505 17.265 1.745
4.675 17.317 1.738
4.845 17.364 1.731
5.015 17.406 1.726
5.185 17.445 1.72
5.355 17.48 1.716
Blinding and false tripping
5.525 17.512 1.711
5.695 17.542 1.707
5.865 17.569 1.704
6.035 17.594 1.7
6.205 17.617 1.697
6.375 17.639 1.695
6.545 17.659 1.692
6.715 17.677 1.69
6.885 17.694 1.687
7.055 17.71 1.685
7.225 17.725 1.683
7.395 17.739 1.681
7.565 17.752 1.68
7.735 17.764 1.678
7.905 17.775 1.677
8.075 17.786 1.675
8.245 17.796 1.674

www.astesj.com 328
 A.F. Agbetuyi et al. / Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 2, 324-331 (2021)
8.415 17.806 1.673
8.585 17.8141 1.672
8.755 17.823 1.671
8.925 17.831 1.67
9.095 17.838 1.669
9.265 17.846 1.668
9.435 17.852 1.667
9.605 17.859 1.666
9.775 17.865 1.665
9.945 17.871 1.664
Blinding and false tripping
10.115 17.876 1.664
10.285 17.881 1.663

Figure 5 shows the plotting of DG penetration (MW) against 𝟐𝟐. 𝟖𝟖𝟖𝟖𝟖𝟖

the protection miscoordination time (PMT) and corresponding DPF = = = 33.8%
𝟖𝟖. 𝟑𝟑
fault current (kA) of the integration of DG into the test distribution
network. and
𝟐𝟐.𝟗𝟗𝟗𝟗𝟗𝟗
The DG penetration level cause protection first DPF = = 35.8% ,
𝟖𝟖.𝟑𝟑
miscoordination to beginning at 0.595MW and 0.765MW, the
second miscoordination occur at 2.805MW, and 2.975MW and The third miscoordination,
third miscoordination occur at 9.945MW and 10.115MW on
𝟗𝟗. 𝟗𝟗𝟗𝟗𝟗𝟗
11kV line with system load of 8.3MW, therefore, false tripping, DPF = = 119.8%
nuisance tripping and blinding of protection occur when the 𝟖𝟖. 𝟑𝟑
penetration of DGs get to the point of fault at the external of the 𝟏𝟏𝟏𝟏.𝟏𝟏𝟏𝟏𝟏𝟏
and DPF = = 121.8%
protection zone, that is when the DGs penetration level increases 𝟖𝟖.𝟑𝟑
fault current beyond the protection relay setting as seen in Table 𝟔𝟔
4. Then, PMI = = 6
𝟏𝟏

DPF = (0.595)/(8.3) = 7.1%

and
DPF = (0.765)/(8.3) = 9.2%
The second miscoordination,
DPF = (2.805)/(8.3) = 33.8%
and
DPF = (2.975)/(8.3) = 35.8% ,
The third miscoordination,
DPF = (9.945)/(8.3) = 119.8% and
Figure 5: Graphical representation of DG penetration
DPF = (10.115)/(8.3) = 121.8%
Recalling equations 1&2
Then, PMI = 6/1 = 6
The first miscoordination,
The calculation shows that the first blinding of protection of
𝟎𝟎. 𝟓𝟓𝟓𝟓𝟓𝟓
DPF = = 7.1% the system beginning at the penetration level of 7.1% and 9.2% of
𝟖𝟖. 𝟑𝟑 DG, and the second false tripping of the protection start when the
𝟎𝟎.𝟕𝟕𝟕𝟕𝟕𝟕 penetration of the DG gets to 33.8% and 35.8% while the third
and DPF = = 9.2%
𝟖𝟖.𝟑𝟑 false tripping protection begins at maximum penetration of DG at
119.8% and 121.8% with the system load of 8.3MW and this is
The second miscoordination,
the best penetration level because the DG is able to accommodate

www.astesj.com 329
 A.F. Agbetuyi et al. / Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 2, 324-331 (2021)
the system load of the injection substation without any further common coupling (PCC) of DGs to the test distribution network
tripping after rest the protection relay.. is important to prevent false tripping, nuisance tripping and
blinding of the protection relay because of the flow of electricity
Also, PMI shows the time of occurrence of miscoordination that change from unidirectional to bi-directional flow.
which is 6 times, that is, the protection miscoordination time at
first miscoordination is 6.984s and 32.572s, the second 6. Conclusion
miscoordination is 1.891s twice, and the third miscoordination is
1.664s twice as seen in Table 4. A single line diagram was developed for the test network, and
the impact of Distributed Generation (DG) on power system
From Table 1, the result of load flow analysis on the test protection was also investigated in this study. It can be concluded
distribution network using Neplan software shows that the active that as the capacity of the penetration level of DGs increases, the
power load loss without DGs is 0.123MW compare with fault current likewise increases while the tripping time of the relay
0.009MW when DGs is connected to the system. It can be protection decreases. This confirms that the integration of DG into
established that the active power load loss is very high without the distribution network causes an increase in the fault current in
DGs connected to the system compared to when it is connected. the distribution network which in turn will affect the protection
This shows that the DGs connected to the distribution network setting. For instance, integration of DGs at 11kV line, in this work,
improves the active and reactive power, as seen in Table 1. causes the miscoordination of protection relay to occur first at the
penetration level of 7.1% and 9.2%, second at 33.8% and 35.8%.
From Table 2, the result of the load flow analysis shows that At the same time, the third false tripping protection begins at the
the voltage profiles at buses 4, 2 and 7 are 0.934p.u, 0.998p.u and maximum penetration level of the DGs at 119.8% and 121.8%.
0.999p.u without DGs connected are compared with voltage Blinding, false and nuisance tripping happened at 32.572s, 1.891s
profiles at buses 4, 6 and 8 are 0.999p.u, 0.999p.u and 1p.u when and 1.664s respectively. The protection relays at the point of
DGs connected to the system. The result confirmed that the common coupling within the test distribution network were
voltage at each bus improved when DGs connected to the test reconfigured to prevent such occurrence again. This was done by
distribution system. From the load flow analysis results, it can be calculating the following: Relay current at fault location, Plug
concluded that the test distribution network is healthy enough to setting multiplier, Pick-up current and the Operating time.
accommodate DGs.
Conflict of Interest
From Table 4, as the penetration of DGs increases from
0.595MW to 0.765MW and from 0.935MW to 1.105MW, the The authors declare no conflict of interest.
fault currents increase likewise from 7.227KA to 8.839KA and
from 10.214KA to 11.369KA respectively at first miscoordination, Acknowledgment
however the time to which the circuit breaker opens the fault
fluctuates from 6.984s to 32.572s and from 6.789s to 4.288s This research work and publication charge is fully funded by
respectively. This is abnormal because the time at which the Covenant University Centre for Research, Innovation and
breaker isolates the fault should not under any condition rise from Discovery (CUCRID).
6.984s to 32.572s and later decrease to 6.789s, so this calls for
protection resetting to prevent the blinding, false, and nuisance References
tripping that has already occurred. [1] T.S. Shomefun, A. Ademola, C.O.A. Awosope, A.I. Adekitan, “Critical
review of different methods for siting and sizing distributed-generators,”
The second miscoordination occurred as the penetration level Telkomnika (Telecommunication Computing Electronics and Control),
is increased from 2.805MW to 2.875MW, thereby causing the 16(5), 2018, doi:10.12928/TELKOMNIKA.v16i5.9693.
fault current also to increase from 16.226KA to 16.4KA. However, [2] T.E. Somefun, C.O.A. Awosope, A. Abdulkareem, A.S. Alayande,
“Deployment of power network structural topology to optimally position
the time to which the breaker isolates the fault is constant at distributed generator within distribution system,” Journal of Engineering
1.891s. This is also abnormal because the time at which the Science and Technology Review, 2020, doi:10.25103/jestr.131.2.
breaker opens the fault should be less than 1.891s. So, this calls [3] J.A. Martinez, J. Martin-Arnedo, “Impact of distributed generation on
for relay resetting to prevent the blinding that has already occurred. distribution protection and power quality,” in 2009 IEEE Power and Energy
Society General Meeting, PES ’09, IEEE: 1–6, 2009,
The third miscoordination occurred as the penetration level is doi:10.1109/PES.2009.5275777.
[4] O. Babayomi, T. Shomefun, Z. Zhang, “Energy Efficiency of Sustainable
increased from 9.945MW to 10.115MW, thereby causing the fault Renewable Microgrids for Off-Grid Electrification,” in 2020 IEEE PES/IAS
current also to increase from 17.871KA to 17.876KA. Moreover, PowerAfrica, PowerAfrica 2020, 2020,
the time to which the breaker opens the fault is constant at 1.664s. doi:10.1109/PowerAfrica49420.2020.9219958.
This is abnormal because the time at which the breaker isolates [5] S.A.M. Javadian, M. Massaeli, “Impact of distributed generation on
distribution system’s reliability considering recloser-fuse miscoordination-
the fault should be less than 1.664s. So this calls for relay resetting A practical case study,” Indian Journal of Science and Technology, 4(10),
to prevent the blinding that has already occurred. 1279–1284, 2011, doi:10.17485/ijst/2011/v4i10/30172.
[6] F. Agbetuyi Ayoade, A. Ademola, H.E. Orovwode, K. Oladipupo
The simulation result confirms that the integration of DGs Oluwafemi, M. Simeon, A. Agbetuyi Oluranti, “Power quality
into the existing test distribution network as shown in Tables 4 considerations for embedded generation integration in Nigeria: A case study
of ogba 33 kV injection substation,” International Journal of Electrical and
causes an increase in the fault current which in turn caused false Computer Engineering, 11(2), 956–965, 2021,
tripping, nuisance tripping and blinding of protection relay doi:10.11591/ijece.v11i2.pp956-965.
compare with when DGs not connected as shown in Table 3. At [7] P.P. Barker, R.W. De Mello, “Determining the impact of distributed
this point, the settings of the protection relay at the point of generation on power systems: Part 1 - Radial distribution systems,” in

www.astesj.com 330
 A.F. Agbetuyi et al. / Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 2, 324-331 (2021)
Proceedings of the IEEE Power Engineering Society Transmission and
Distribution Conference, IEEE: 1645–1656, 2000,
doi:10.1109/pess.2000.868775.
[8] T.E. McDermott, R.C. Dugan, “Distributed generation impact on reliability
and power quality indices,” in Rural Electric Power Conference, 2002. 2002
IEEE, IEEE: D3-1, 2002.
[9] S. Conti, “Analysis of distribution network protection issues in presence of
dispersed generation,” Electric Power Systems Research, 79(1), 49–56, 2009,
doi:10.1016/j.epsr.2008.05.002.
[10] A. Girgis, S. Brahma, “Effect of distributed generation on protective device
coordination in distribution system,” in LESCOPE 2001 - 2001 Large
Engineering Systems Conference on Power Engineering: Powering Beyond
2001, Conference Proceedings, IEEE: 115–119, 2001,
doi:10.1109/LESCPE.2001.941636.
[11] E. Sortomme, G.J. Mapes, B.A. Foster, S.S. Venkata, “Fault analysis and
protection of a microgrid,” in 40th North American Power Symposium,
NAPS2008, IEEE: 1–6, 2008, doi:10.1109/NAPS.2008.5307360.
[12] G. Kaur, Y. Mohammad Vaziri, “Effects of Distributed Generation (DG)
interconnections on protection of distribution feeders,” in 2006 IEEE Power
Engineering Society General Meeting, PES, IEEE: 8, 2006,
doi:10.1109/pes.2006.1709551.
[13] E. Coster, J. Myrzik, W. Kling, “Effect of Distributed Generation on
Protection of Medium Voltage Cable Grids,” in Proc. CIRED 19th Int. Conf.
Electricity Distrib, 21–24, 2007.
[14] B. Hussain, S.M. Sharkh, S. Hussain, “Impact studies of distributed
generation on power quality and protection setup of an existing distribution
network,” in SPEEDAM 2010 - International Symposium on Power
Electronics, Electrical Drives, Automation and Motion, IEEE: 1243–1246,
2010, doi:10.1109/SPEEDAM.2010.5545061.
[15] H. Zayandehroodi, A. Mohamed, H. Shareef, M. Mohammadjafari, “Impact
of distributed generations on power system protection performance,”
International Journal of Physical Sciences, 6(16), 3873–3881, 2011,
doi:10.5897/IJPS11.674.
[16] S. Rahman, Impact of Distributed Generation on Power System Protection
PV-STATCOM View project Traction power analysis View project, 2010.
[17] R. Elavarasi, P. Saravanan, Impact of Distributed Generation on Distribution
Systems and its Protection, 2014.
[18] M. Khederzadeh, H. Javadi, S.M.A. Mousavi, “Source type impact of
Distributed Generation (DG) on the distribution protection,” IET Conference
Publications, 2010(558 CP), 2010, doi:10.1049/cp.2010.0299.
[19] T.E. Somefun, O. Babayomi, C.O.A. Awosope, A. Abdulkareem, C.T.
Somefun, “Software for Improved Online Teaching of Power System
Analysis for Undergraduates,” in 2020 IEEE PES/IAS PowerAfrica,
PowerAfrica 2020, 2020, doi:10.1109/PowerAfrica49420.2020.9219910.
[20] J. Mutale, G. Strbac, S. Curcic, N. Jenkins, “Allocation of losses in
distribution systems with embedded generation,” IEE Proceedings:
Generation, Transmission and Distribution, 147(1), 7–14, 2000,
doi:10.1049/ip-gtd:20000003.
[21] T.M. Masaud, R.D. Mistry, “Fault current contribution of Renewable
Distributed Generation: An overview and key issues,” in 2016 IEEE
Conference on Technologies for Sustainability, SusTech 2016, IEEE: 229–
234, 2017, doi:10.1109/SusTech.2016.7897172.

www.astesj.com 331