  This paper proposes a distributed sliding mode control strategy for optimal
Load Frequency Control (OLFC) in power networks, where besides frequency
regulation also minimization of generation costs is achieved (economic
dispatch). We study a nonlinear power network partitioned into control areas,
where each area is modelled by an equivalent generator including voltage and
second order turbine-governor dynamics. The turbine-governor dynamics suggest
the design of a sliding manifold, such that the turbine-governor system enjoys
a suitable passivity property, once the sliding manifold is attained. This work
offers a new perspective on OLFC by means of sliding mode control, and in
comparison with existing literature, we relax required dissipation conditions
on the generation side and assumptions on the system parameters.
