The paper addresses the problem of the robust output feedback PI controller design for complex large-scale systems with stateoutput decentralized structure. The proposed design method is based on the Generalized Geršgorin Theorem and the V-K iterationmethod to design robust PI controller guaranteeing feasible performance achieved in subsystems level and for the full system. Theproposed method excludes limit of system order in LMI solution, while PI controller design procedure is feasible on the subsystemlevel. Finally, numerical example is given to illustrate the effectiveness of the proposed method
