Abstract:
The final step in getting electricity to consumer is the distribution system. The transmission
system's power is delivered to consumers via this system network. Insufficient power quality for
bus voltage, a flow of real power, and reactive power are present in the radial distribution system.
In an electrical power system, the voltage decreases due to reduced reactive power, the voltage
decreases. Thus, it is not possible to push the power demand to loads through the lines and has an
adverse impact on system stability. Many attempts have been made to improve these issues. This
thesis was done by using SVC in Jijiga distribution system feeder 4 to reduce power loss and
improve existing voltage profile. SVC is shunt FACTs devices that is used to improve the
performance of distribution system. To maintain the rated voltage within acceptable limit at load
end, low rated static VAR compensators (SVC) was installed at buses operated below specified
limit. This research takes Optimal Capacitor Placement (OCP) to determine under operated buses
in the system and rating of SVC in Electrical Transient Analyzer Program (ETAP). Modeling and
Simulation of the distribution network with and without SVC had been developed in the Electrical
Transient Analyzer Program (ETAP) environment. Power flow analysis of Jijiga distribution
network was performed to calculate the various values of voltage and power flow in the
distribution system. Also, Load flow analysis of Jijiga distribution network feeder four including
static var compensator (SVC) in ETAP was performed to keep voltage profile within ±10% of the
rated voltage. Before compensation, the simulation result was observed and the minimum and
maximum bus voltages value were 89.311 % (bus 95) and 93.190% (bus2) respectively and which
were improved to 94.926% (bus95) and 97.944% (bus 2) after compensation, respectively. Hence,
When SVC was connected to the most weak buses, minimum and maximum bus voltage value
were 90.202% (bus 84) and 97.944% (bus 2), respectively. The voltage drop before and after SVC
placement was obtained as 0.5612pu and 0.4862pu respectively. Hence, the total voltage profile
improvement measured based on the reduction in total voltage deviation (TVD) of Jijiga
distribution network was obtained as 13.36%. Also, simulation result before compensation of
SVC shows total losses of active and reactive power were 557.7KW and 876.2KVAr. After SVC
was connected to the weakest buses, the active and reactive power loss became 293.7KW and
370.5KVAr. Hence, the loss saving was obtained as 264KW, with the total SVC size of 4.9MVAr
capacitive and 9.8MVAr inductive.
Keywords: - Bus Voltage Improvement. ETAP, SVC, Power Flow Analysis, Radial
Distribution.