Sparse and Distributed Control of Wide-Area Power Systems with Large Communication Delays

A sparse and distributed optimal control strategy is proposed for wide-area control of power systems in the presence of large network delays. Sparsity is introduced in the underlying communication network on the basis of dominant participation of the state variables in the inter-area oscillation modes that decides which generators should communicate with which other generators, and included in the control design. In addition, the controller accommodates large network delays that are of values four to five times greater than the sampling period. A virtual sparsity concept is introduced to accommodate these delays by zeroing out the gains that correspond to measurements that are yet to arrive. Results are verified through a simulation study of the IEEE-39 bus power system model, where it is shown that with 86% less communication channels, we can obtain nearly 89% of the performance compared to the case with a non-sparse controller.