TITLE:
Transient Stability Analysis of 33 KV Transmission Network of Egi Community, Nigeria
AUTHORS:
Promise Elechi, Christopher Okwuchukwu Ahiakwo, Ugochukwu Nureedin Okwu
KEYWORDS:
Rotor Angle, Transient Stability, Swing Equation, Angular Speed, Differential Changes, Trapezoidal Rule, Fault Clearing Time, Critical Clearing Time
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.8 No.3,
March
27,
2020
ABSTRACT: Transient
analysis of 33 KV power transmission line stability of Egi communi-ty is
considered in this research work with the aim of reducing the frequency of
fault occurrence and voltage collapse in the network. The supply is taken from
Egi generating station located at Total Nigeria Limited Gas Plant Obite at
voltage level of 33 KV to Egi communities. This work focuses on the transient
nature of network stability since transient fault is the most dangerous in
elec-trical systems. The swinging of the generator rotor in the event of
transient three-phase short circuit fault can be monitored by the circuit
breakers and the protective relays which causes mal-functioning of the circuit
breakers and pro-tective relays leading to abnormal behavior of the network. Therefore,
data obtained from the power station were used as a case study of Independent
Power Producer (IPP) in Nigeria. For investigation of the power angle, angular
velocity, rotor angle differential changes, and angular velocity differential
changes, an electrical transient analyzer tool was employed (ETap version
16.00) for circuit breaker and protective relay time setting of (0.00, 0.05,
0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60). The work
used the Trapezoidal numerical technique for data analysis. The graphs were
plotted using Matlab R2015a and the results obtained showed that when a
symmetrical three-phase short circuit fault occur at one or any of the feeders,
the fault must be cleared as quick as possible through the coordination of the
circuit breakers and protective relays. For this research work, 17 cycles
corresponding to relay time setting of t = 0.34 s were recommended and at each
cycle, changes in time with respect to changes in rotor angle, angular
velocity, rotor differential and angular velocity differential were calculated
on the power network simultaneously. The results demonstrated that the
Trapezoidal method is numerically stable, accurate and has faster respond time
when compared to Modified Euler and swing equation techniques in event of fault
occurrence in network.