Automatic generation control of multi-area power systems using reduced order controller

The paper presents a reduced order controller for the automatic generation control of multi-area power systems. The proposed technique exploits the recent properties of balanced state space representations to develop a new reduced suboptimal control scheme. Due to the weak interconnection between the subsystems of the balanced model, the resulting decoupled system representation can be viewed as an approximate aggregation. The original modes of the system are therefore approximately conserved. The reduced control laws are then derived based on strongly controllable/observable and weakly controllable/observable subsystems. Suboptimal control law aggregation is used for comparison. The two methods are evaluated and comparison with the optimal control law is performed and applied to a multi-area interconnected power systems. Performance degradation, mainly suboptimality degree is evaluated for the two methods for different cases by varying the weights in the quadratic cost. The simulation results show that the balanced scheme outperforms the closed loop suboptimal control based on aggregation.