A technique for optimal digital redesign of analog controllers

Digital control design is often accomplished by discretizing existing analog controllers. For this purpose, a new digital redesign technique is presented in this paper. It is based on optimal matching of the continuous-time closed-loop step responses of both the analog and discretized systems. The optimization problem is solved by application of the recent sampled-data control theory. The proposed technique is applied to discretization of a conventional power system stabilizer for a single-machine power system and the simulation results show that the new optimal digital redesign technique outperforms the conventional discretization methods