Multi-machine fractional-order power system stabilizers

A fractional-order power system stabilizer (FoPSS) is introduced to control the frequency and the terminal voltage deviation in a multi-machine power system connected to an infinite bus. The proposed controller is a generalization of a FoPSS applied to a single machine connected to an infinite bus. A significant improvement has been achieved using FoPSS over an integer-order power system stabilizer (IoPSS). The numerical simulation shows that stability of the multimachine system is maintained with and without an excitation system when using the FoPSS. The FoPSS is more robust and can sustain sever conditions and wider range of operating points.