Set point adjustment strategy for mitigating transients in a microgrid

This paper proposes an improved prediction algorithm for SPAACE, a strategy for mitigating transients at a distributed energy resource (DER) caused by disturbances in a microgrid. Controllers used by DER units are typically tuned for grid-connected operation of a microgrid. However, islanded operation changes the dynamics of the system making it more susceptible to large transients that may violate the operational limits of the system. The previously proposed strategies are called set point automatic adjustment with correction enabled (SPAACE) and SPAACE with prediction enabled. SPAACE works by tracking the output of a system (e.g., current, voltage, or power) and adjusting its controlled set point during violations in order to shape the trajectory to a desired form. SPAACE with prediction works similarly but adjusts the set point based on predicted values of the system output. Case studies are presented to demonstrate the ability of the improved strategy to mitigate transients in current and voltage control modes.