On the Assessment of Power System Stability Using Matlab/Simulink Model

Several voltage collapses have been experienced by most practical power systems in recent times in Nigeria. These have been mostly attributed to island formation within the network as a result of switching out of critical buses within the network. This paper assesses the stability of a practical power network of the Nigerian National Grid (NNG) with reference to a critical transmission line which could cause island formation as a result of fault within the NNG network. The Matlab/ Simulink model for both the steady-state and dynamic behaviours of the critical bus within NNG network is presented. The simulations for various fault conditions are also presented. The results obtained from the simulations are discussed. From the simulation results, high flow of reactive power and current, as a result of various faults along the transmission lines, were observed. Furthermore, non-sinusoidal waveforms generated from the simulation results show an indication that a high degree of compensation is required at the studied bus. The study uses Benin bus of NNG with respect to Benin-Onitsha-Alaoji 330-kV transmission network due to its location and sensitivity within the grid.