  Protection strategies for transmission and distribution systems have been
extensively investigated to facilitate better coordination of physical
protection devices. A diverse range of functional motors with dedicated
protection schemes are being used more and more in commercial, residential, and
industrial buildings. This paper focuses on simulating several of the most
popular protection schemes using the ElectroMagnetic Transient Program (EMTP)
model for three-phase and single-phase induction motors in existing commercial
buildings connected to typical distribution feeders. To investigate the
behaviors of single-phase motors stalling, the actions of motor protection and
reconnections, and the impacts of device-level protection on system-level
dynamics, we imposed voltage depressions at the head of a feeder fully loaded
with functional induction motors. Several distribution feeders are represented
in a standard IEEE 39-bus transmission system to simulate fault-induced delayed
voltage recovery (FIDVR) and explore mitigation strategies by optimally
configuring the building-level motor protection settings.
