Application of df/dt in power system protection and its implementation in microcontroller based intelligent load shedding relay

Abstract

Several practical intelligent setting schemes that consider the effect of df/dt are suggested and simulated for a power system operating in an underfrequency situation. Considerations for df/dt relay setting are discussed. These intelligent setting schemes have made a positive improvement in the underfrequency condition. As an extension of these new intelligent control schemes, a microcontroller based intelligent under/over frequency relay is introduced. With its advanced hardware and intelligent software, this microcontroller has the advantages of high flexibility, less cost, and high communication ability.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>