Coordinated design of local and wide-area damping controllers for power systems using particle swarm optimization

This paper describes an approach to coordinate the design of local and wide-area controllers for damping electromechanical oscillations in power systems. Some of the limitations of local controllers are first illustrated by simulations on a system exhibiting nearly decentralized fixed modes. These are modes that cannot be appreciably shifted using permissible local controls. Wide-area controllers with measurements from distant locations across the system are then added to improve the damping of these modes. The design procedure consists of finding the optimal parameters for local and wide-area controllers that minimize an eigenvalue-based objective function. All controllers are optimized simultaneously to improve coordination. The linear power system model used for control design is obtained by system identification. The optimization problem is solved using particle swarm optimization, which has been shown to be effective for designing local PSSs in the past. Numerical results for a 16-machine/68-bus benchmark power system model demonstrate the effectiveness of the approach.