Journal ID : TRKU-19-02-2021-11430
[This article belongs to Volume - 63, Issue - 03]
Total View : 461

Title : Incidences of Voltage Collapse in the Nigerian Power System: Data and Analysis

Abstract :

The work presents a study of voltage collapse in Nigeria Power Network. This involves the series of events accompanying voltage instability which lead to a blackout or abnormally low voltages in a significant part of the power system. The cause of this can be categorized into two; technical and non-technical. The technical causes may be due to tripping of lines on account of faulty equipment or increase in load than the available supply. The data comprising the series of system collapse experienced by the Nigeria power system since 2000 to 2020 were presented and analyzed so as to view the frequency of the occurrence of the collapse. Also, suggestions were given on the ways to reduce the incidence of system collapse on the power system. The need for an approach to voltage collapse margin which is to return back the system to steady state by injection/compensation of reactive power on the transmission lines becomes urgent with other use of tap- changing transformers and load shedding strategies. These compensators which are presented in this work are SVC, STATCOM, TCSC, SSSC and UPFC are the approaches used. PSAT software which makes use of Newton-Raphson’s iterative method was used to simulate the existing 52-bus system of Nigeria which displayed high accuracy and converged in few numbers of iterations. SVC and STATCOM were first used separately to compensate bus1 (0.9673pu) while TCSC, SSSC and UPFC were later used separately to compensate the system. Results obtained showed that the use of dynamic shunt compensators (SVC and STATCOM) maintained the bus 1 voltage at 0.9673pu while the use of series compensators (TCSC, SSSC and UPFC) slightly maintained a power flow of 80MW and bus 1 voltage at 0.9673pu after several increases in loadings. It is with this that the research work presents the use of series compensators on the transmission lines as the optimal approach to voltage collapse in Nigerian Power system. An Optimal site for the placement of the series compensator is at Bus 8 (Jos) and Bus 9 (Gombe) which have the lowest loss of sensitivity index. The installation of any of the series compensators in Nigeria power network keeps the system in steady state at all times.

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