Decentralized Robust Output‐Feedback Control for Multimachine Power Systems

The transient stability problem in nonlinear (NL) multimachine power systems (MPS) is addressed using a set of linear–decentralized (LD) output‐feedback (OF) controls, one per machine. First, the standard MPS model is realized as a set of LD robustly controllable‐observable models with augmented states (one per machine) that account for the effects of NL model error due to parameter approximation, as well as intermachine interconnections. Then, an LD OF robust transient stabilizing control is designed: (i) by implementing an LD state‐feedback (SF) control with an LD geometric state estimator and (ii) with a robust closed‐loop stability condition coupled with a transparent pole placement–based tuning scheme. With respect to its traditional industrial power system stabilizer (PSS) and automatic voltage regulator (AVR) counterparts, the resulting LD OF control design: (i) improves CL robust functioning and (ii) offers a more systematic means to construct the control and tune its gains.