Designing Decentralized Load-Frequency Controllers: An Optimization Approach for Synchronous Generators in Islanded Grids

In this article, an optimal decentralized controller is designed for the load-frequency control (LFC) of a multiarea islanded grid with multiple synchronous generation systems. The decentralized controller includes various proportional-integral (PI) controllers that are simultaneously designed and optimized by using a classical descent-direction quasi-Newton (QN)-based technique. Optimal decentralized PI controllers account for the dynamic coupling amid the areas of the islanded grid with no communication links among them required and, hence, improve the frequency control performance. Simulation results confirm the effectiveness of the proposed decentralized PI control approach. The suggested PI controllers have a similar performance to decentralized eighth-order, linear-quadratic-Gaussian (LQG) integral controllers, which are designed in the decentralized servomechanism framework, whereas the proposed decentralized PI controllers have considerably lower-order structures.