Power system oscillations and control: Classifications and PSSs' design methods: A review

In this paper, a review of the classifications of power system oscillation modes, as well as power system stabilizer (PSS) design structures, is proposed. Four major oscillation modes and their effects on power system stability have been investigated and analyzed, and the critical elements affecting each mode, frequency range, and PSS application have been summarized using important published work. Next, the PSS's structure has been classified according to the number of inputs and compensation filters, and a combination of the PSS with the intelligent systems, optimal evolutionary-based, and non-intelligent adaptive-based PSS has been highlighted. The effect of the oscillation modes in Great Britain's (GB) power system has been identified, as well as the possible solutions to damp this oscillation. It was found that the inter-area and the local machine modes have a greater impact on wide area power system stability and sustainability. Integrating new Renewable Energy Resources (RESs) can lead to more transient and dynamic instability. Therefore, more research is required to design solutions to tackle this grave problem. Four PSSs presented in the literature have been applied and tested in two different multi-machine Benchmark systems.