Design and real time implementation of LMI based robust damping controllers for power systems

This paper demonstrates the design and implementation of a robust damping controller for damping the low frequency (0.1-2 Hz) electromechanical modes in an interconnected power system. The robust control design is formulated as H_infin norm optimization problem and the solution is sought numerically using LMIs. This allows additional pole-placement constraints to be imposed to ensure that the time domain specifications are met beside robust stabilization. Due to relatively large size and other peculiarities of the resulting controller, real time implementation is often a concern in practice. Therefore, implementation and performance validation of such a controller in real time is presented is this paper. One issue, however, is the availability of the actual system for validating the performance of the controllers in real time. Hence, a real time dynamic system emulator has been developed as a test bench to validate the designed control algorithm in a hardware-in-loop configuration.