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CUSTOMIZED INTERLINE POWER FLOW CONTROLLER FOR VOLTAGE PROFILE IMPROVEMENT AND POWER LOSS MINIMIZATION OF TRANSMISSION LINE (CASE STUDY: SOUTHERN REGION FROM SHASHEMENE TO BUKULUGUMA TRANSMISSION SYSTEM)
(Hawassa University, 2024-03-21) ASRAT LEMMA
An electrical system is a collection of components that are used to supply, transmit, and consume
electricity. Transmission lines effectively transfer the electricity produced by different power
plants. Nevertheless, the generated electricity is not entirely supplied to customers because of
voltage drop and power loss. Uncontrolled bus voltage profile caused problems for industries that were
developing quickly. Interline power flow controller (IPFC) is a type of flexible AC transmission
system (FACTs) devices applicable to reduce power loss and enhance voltage profiles of the
transmission networks from Shashemene to Bukuluguma transmission system. Load flow analysis
on nine buses were performed by Newton Raphson load flow analysis technique using MATLAB
R2016a. The analysis showed that out of nine buses four buses are out of voltage limit. On the
system as a whole, there has been a loss of 8% real power and 10.42% MVAr reactive power, or
7.322MW and 4.530 MVAr, respectively. To minimize the loss problems, grey wolf optimization
(GWO) techniques were proposed to search optimal place and size of interline power flow
controller (IPFC), placed on bus 5, and sized 27MVAr. GWO techniques are compared with
Antlion optimization, but GWO gives a good performance. After analysis data 4 buses bus number
4, 7, 8, and 9 are out of permissible values, the remaining buses are within acceptable limits. GWO
techniques suggest implementing the lowest voltage stability index bus. After installing IPFC in
optimal power flow place the network problem is improved by GWO 6.1% and ALO 3.9%, the
lowest case voltage profile improved from 0.937pu to 0.978pu and 59.7% of active power and
40% of reactive power are saved. Finally, the reduction result suggest that the recommended
approach is operative to regulate all buses voltage magnitudes within the NEC and IEEE
permissible boundary and to minimize power loss considerably
TRANSMISSION LINE VOLTAGE PROFILE IMPROVEMENT AND POWER LOSS REDUCTION BY OPTIMAL PLACEMENT OF STATIC SYNCHRONOUS COMPENSATOR USING TEACHING LEARNING BASED ALGORITHMS
(Hawassa University, 2022-03-18) Mulye Getu
The power transmission system transports electric power generated at generation plant to
distribution system. The increasing power demand of customers causes the power
transmission system to become stressed when connected to distribution system. This leads to
voltage instability and, further to, transmission power loss, which can lead to power system
malfunction and system collapse. Most bus voltages are not within acceptable limits, and the
voltage index of the buses indicates that the network is prone to voltage instability issues.
The objective of this thesis is to determine the best placement for a static synchronous
compensator (STATCOM), which is one of the Flexible AC Transmission Systems
(FACTS) devices, on the Alaba to Bukuluguma Transmission System network to minimize
transmission line loss, improve voltage profile, and enhance power transfer capacity. The
power flow analysis by Newton Raphson algorithm in MATLAB environment is used and
Teaching Learning-based optimization techniques (TLBO) are adopted for optimal sizing
and location of the device. The obtained results were compared to those reported in the
literature for conventional optimization techniques. The optimal location and size of
STATCOM for the Alaba to Bukuluguma transmission network were identified using the
genetic algorithm (GA) and particle swarm optimization (PSO) methods accordingly,
25.8MVar at bus 6 and 25.5 MVar, at bus 5 respectively. According to the TLBO technique,
bus 4 with 25MVar is the best placement and size of STATCOM in the network. The TLBO
approach, as previously indicated, performs better in terms of reducing real and reactive
power losses. The test system's real power loss reduction is 39.8 percent, while the reactive
power loss reduction is 49.3 percent. In addition, the worst-case minimum voltage level has
been enhanced from 0.878pu to 0.953pu. STATCOM control is established in this study
utilizing artificial intelligence (AI) and an artificial neural network (ANN), which is based on
TLBO's optimal values. In general, simulation results demonstrate that the suggested
approach is effective in keeping all bus voltage magnitudes within the IEEE permissible limit
while also drastically reducing power losses.
OPTIMAL CO-ORDINATION SYSTEM FOR OVER CURRENT, &EARTH FAULT PROTECTION RELAYS IN SEBETA-I SUBSTATION BY USING WHALE OPTIMIZATION ALGORITHM
(Hawassa University, 2024-04-27) Alem Niguse
Protection and coordination of substation system networks is one of the most substantial issues in
power systems. Over-current, earth fault relays, and differential protection are the systems’ most
commonly used protective relays. The coordination of inverse time over-current relays is
formulated as a linear programming problem. The optimization technique aims to minimize the
relays’ time dial settings (TDS). The settings for this type of relay can be categorized into two
current and time settings. The most significant variable in the optimal coordination of over current relays is the time multiplier setting (TMS). Protective relays are essential devices for
electrical power protection systems. The choice of protection devices depends on the type and
rating of the protected equipment. The primary function of the relay is to clear fault current
flowing through the system at faults that have occurred in the protective line. This thesis focuses
on optimal over-current, earth fault, and differential protection coordination schemes for the
Sebeta-1 substations. The voltage level of this substation is 132KV, and it has eight low-voltage
outgoing lines, two incoming feeders, two incoming power transformers, and two 132KV
incoming lines. This substation system network is one of the oldest and most important
substation system networks in Ethiopia’s electric power Addis Ababa region, and also the
maximum load of the city is connected from this substation. However, their coordination is not
properly coordinated, and networks based on this improper coordination, interruption of power is
frequently a phenomenon in the network. The main reasons are the system is saturated, the
network system is old, there is a short circuit current, an earth fault, overloading, and also
improper coordination and protection of the distribution network. When faults occur in one line,
they create a high over-current. Due to the higher load, more of the network lines are out of
service due to faults in some parts of the network. Clearly, in this case, the number of interrupted
customers rises, and accordingly, the power quality decays. From analyzing the obtained results,
it has been found that the whale optimization technique provides the most globally optimum
solutions at a faster convergence speed. This algorithm finds the best solutions out of all
optimization solutions. Using MATLAB programming gets the best optimization results
Impact of Distributed Generation on Distribution Network Protection scheme and Adaptive Protection Coordination using Harris’ Hawks Optimization
(Hawassa University, 2022-12-27) ABENEZER KASSA USAMO
The Modern Power System which has grown both in size and complexity, that means requires
fast, accurate and reliable Protective schemes for protecting major equipment’s and to maintain
system stability and reliability. Distribution networks are evolving into active meshed networks
with bidirectional power flow as the penetration of distributed generation (DG) sources is
increasing. Interconnecting DG to an existing distribution system provides various benefits to
several entities as for example the owner, utility, and the final user. DG provides an enhanced
power quality, higher reliability of the distribution system and can peak shaves and fill valleys.
Penetration of a DG into an existing distribution system has many impacts on the system, with
the power system protection being one of the major issues. This necessitates the use of
directional relaying schemes in these emerging active distribution networks. However,
conventional directional overcurrent (OC) protection will not be adequate to protect these
networks against the stochastic nature of DGs and the changing network architectures. Hence,
this study proposes an adaptive directional overcurrent relay algorithm that determines optimal
protection settings according to varying fault currents and paths induced by the DGs in active
meshed distribution networks. Location and technology of the DG sources are changed to study
the effect that these changes may have on the coordination of protective directional over-current
relays (DOCR). Results are compared to that of the normal case to investigate the impact of the
DG on the short circuit currents flowing through different branches of the network to deduce the
effect on protective devices.
This study presents an adaptive protection coordination scheme for optimal coordination of
DOCRs in interconnected power networks with the impact of DG. The used coordination
technique is the Harris Hawks Optimization (HHO), selected due to adaptive & time-varying
parameters allows HHO to handle difficulties of search including local optimal solution, multi modality & deceptive optima. Adaptive relaying describes protection schemes that adjust settings
and/or logic of operations based on the prevailing conditions of the system. These adjustments
can help to avoid relay miss-operation. Adjustments could include, but are not limited to, the
logging of data for post-mortem analysis, communication throughout the system, as well
changing relay parameters. Several concepts will be discussed, one of which will be
implemented to prove the value of the new tools available. The optimal coordination of DOCR is
find by with MATLAB code using HHO technique and the adaptive protection scheme model
will develop in DIgSILENT/Power Factory. The results validate the ability of the proposed
protection scheme to capture the uncertainties of the DGs and determine optimal protection
settings, while ensuring minimal operating time
Implementation Challenge of School Management Information System (SMIS): (the Case of Alem-Gebeya Town Public Secondary School) Thesis submitted to the Department of Information Technology in partial fulfillment of MSc, in Information Technology
(Hawassa University, 2024-04-17) WABELA KEMAL
The study helps to investigated the factors those contributed to the implementation challenge of
the School Management Information System (SMIS) technology the case of Alem-Gebeya Town
Public Secondary school. The produced & distributed the equipment of the innovative School
Management Information Systems’ (SMIS) technological tool has been in-placed at the Alem Gebeya Town Public Secondary school, however it has disservice in the peripheral area, and due
to this automating school’s daily activities have been difficulty problem in the peripheral area.
The theoretical parts of the study aimed at gaining information about Personal, Internal, and
External related socio-economic factors that contributing to the implementation challenges of
the automated system, to identify associated effects in the study area.
The selected School survey study required in the study area in order answered the following the
three research questions:- (1) what are the sources of contributing factors to the implementation
challenge of School Management Information System (SMIS)?; (2) How to determine the
influences of factors that contributed to the implementation challenge of School Management
Information System (SMIS)? and (3) how to investigate the influences of factors to address the
challenges in the study area?
The study adopted descriptive survey and employed both Quantitative & Qualitative research
methods. In the actual research survey in probability sampling selection approach the researcher used
simple random and purposive sampling techniques to administer questionnaire to each sampled
respondents. Accordingly noted by (Kothari’s) determination of sample size formula 46
respondents were chosen from the total 66 academic and administrative staffs in the selected
school. The researcher used questionnaires, interviews and observation as Data collection tools
and techniques. The collected data were analyses on the use of Statistical Package for Social
Science (SPSS-27.0.1) application soft ware tool on the descriptive statistics techniques like
mean, standard deviation, frequency and percentages. The background of the respondents’
information presented within tabular frequency and percentage. The results of the study shown
Personal, Internal, and External related socio-economic factors and the respondents’
demographical factors influenced the implementation of the automated School Management
Information System (SMIS) technology in the study area. Due to this, most common mode of the
school works on manual-based, which is inefficient and ineffective in the selected school. The
study recommended:- the secondary school’ academic and administrative staffs should take concrete
corrections on their poor perceptions toward easefulness, usefulness and availableness of the
automated SMIS system. Schools should know the produced the SMIS technology surely has not
usability issues (problems) on the school works, which means it is trust full for any school’s task
management procedures. The automated SMIS technology would have required attempter school.
Hence, the school should attempt to implement it in their task management procedures. Schools should
take concrete corrections regard reporting data through using the automated SMIS technology will
punish our school’s political situation (hint: finance audit, students dropout, pass & fail,
bureaucratic). In addition, officials and schools should establish organized the SMIS teams/committees
in school level up to officials in the study area