Cogeneration application: interconnection of induction generators with public electric utility

A brief review is presented of induction generator theory and a discussion is presented of required reactive power for excitation, overvoltage, harmonics and fault contribution associated with the induction generator. Coverage is also provided of the following studies required for interconnection of the induction generators with the public electric utility: load flow, short circuit, stability, protective relaying requirements and protective device coordination studies. It is shown that the induction generator does not require a separate DC excitation system and synchronizing is not required. Because of its simple rugged construction, the induction generator is inherently a low maintenance machine compared to the synchronous machine and has higher expected reliability