Dynamic and steady-state analysis of integrating solar photovoltaic power plants into the high-voltage transmission network

This paper examines the steady-state and dynamic analysis of injecting solar PV into the southern interconnected grid (SIG) of Cameroon. This is crucial as Cameroon is making reasonable progress to increase the quantity of renewables in the electricity generation mix. To perform the analysis, preconceived solar PV injection are executed on selected busbars in the grid, while the transient and steady-state conditions of the network are monitored. The PV injections were modeled at 10% interval and the injections were executed in increments of 10% right up to 100%. The load flow analysis was conducted using the Electrical Transient Analyzer Program (ETAP). A transient scenario was initiated at the Kribi 225 bus, while the impact on bus voltages and frequency as well as rotor angle of generators were investigated. The results showed that PV integration has positive impacts on grid performance during transient conditions to a certain extent, above which negative effects start manifesting. For example, the active power loss (PLoss) at the Bekoko busbar as the PV injection increased was dropping right up to 30% PV injection and increased greatly thereafter. Moreover, the main busbar voltages improved to a point, where they equally started deteriorating. As solar PV injection attained 50% at the Oyomabang 93 bus, the Kribi generators’ rotor angles failed to regain synchronism after the clearing of the fault. This makes 30% the optimum PV injection capacity in the network. For PV injections at the Kondengui, Limbe, Bekoko, Oyomabang, Nomayos, Bassa and Ngousso busbars, the power losses were initially decreasing with increase in penetration level up to a certain penetration level, above which the losses started increasing as the PV injection rose. The analysis will help system operators to make informed decisions and execute appropriate mitigation strategies.