The dynamic characteristics of power system loads are critical to obta
ining quality operating point prediction and stability calculations. T
he composition of components at a load bus makes the aggregated behavi
or too complicated to be expressed by a simple form. Armed with the th
eorems recently developed on the approximation capability of artificia
l neural networks we devise a load model to describe the complex dynam
ic behavior of loads. Real field data are used to train and test this
model. The results verify that this model can emulate load dynamics we
ll and should therefore be suitable as a representation of load for st
ability analysis.