PNNL

Abstract

Protection plays a critical role in determining the dynamic response of the induction motor loads and the overall performance of composite load models when subjected to voltage sags or disturbances. Up to date, due to lack of understanding of the aggregate performance of the protection of motors, protection modeling of the motors becomes one of the least accurate parts in dynamic (composite) load models. This paper fills this gap by providing detailed analysis of the motor loads and their associated protection in commercial buildings and deriving the aggregate protection response based on integrated transmission and distribution dynamic co-simulation. The results showed that the aggregate protection response of motor loads varies significantly among different classes, which indicates the protection modeling that has been developed based on the assumption of similar or even identical responses and used in some composite load models need to be updated.