In Chap. 7 , we showed that power system stabilizers act efficiently to damp the electromechanical oscillations in interconnected power systems. When the stabilizers are correctly tuned, the resulting damping control is robust. Power system stabilizers are cost-effective when compared to the alternative, purely electronic controls, e.g., static VAr compensators—we will consider these in Chap. 10 . However, over the years of power system stabilizer use, a number of problems have arisen. These are often cited as reasons not to install power system stabilizers, but this is not valid. Methods to rectify the problems have been found and we will discuss the problems and their solutions in some detail in this chapter.