Cascading Stall of Many Induction Motors in a Simple System

After an initial fault lowers bus voltage, induction motors connected to the bus can successively stall in a cascading process that can lead to a voltage collapse or delayed voltage recovery. There are typically many induction motors connected to the bus, and models that aggregate the motors do not capture the cascading stall. We study the cascading stall in a simple power system with many induction motors using a quasistatic assumption and randomization of some motor parameters, and hence efficiently estimate the distribution of the number of motors stalled. This approach is also extended to a simple four-bus system and a simple motor dynamics and similar results are obtained. These distributions can often be fit with a high-level and generic probabilistic model of cascading failure, showing a commonality between cascading motor stall and other cascading processes.