Load frequency control design in state space

Load-frequency control (LFC) is a fundamental issue in power engineering. It aims to maintain the frequency of power networks and the interchange powers between local areas at nominal values. This chapter presents essential knowledge for modeling, analyzing and designing decentralized LFC systems using state-space representation. Because of its accessibility, simplicity and flexibility, passivity theory is introduced to deal with complex power networks which consist of massive local areas with various components. The approach is demonstrated by several design examples with numerical simulations.