There have been many models developed to represent electric loads, How
ever, the identifiability problem of load models has not been studied,
that is whether the parameters of a model can be identified from a sp
ecified input-output experiment, A study is made of the identifiabilit
y of electric load models, and the basic concepts and definitions are
introduced. Structural identifiability and input identifiability are s
tudied and numerical identifiability is discussed.