This book provides a comprehensive study of multi-stage and multi-time scale design of feedback controllers for linear dynamic
systems. It examines different types of controllers as can be designed for different parts of the system (subsystems) using
corresponding feedback gains obtained by performing calculations (design) only with subsystem (reduced-order) matrices.The
advantages of the multi-stage/multi-time scale design are presented and conditions for implementation of these controllers
are established. Complete derivations and corresponding design techniques are presented for two-stage/two-time-scale, three-stage/three-time
scale, and four-stage/four-time-scale systems. The techniques developed have potential applications to a large number of real
physical systems. The design techniques are demonstrated on examples of mathematical models of fuel cells, especially the
proton exchange membrane fuel cell.