State variable description of dynamic load models in electrical power system analysis

This paper relates to methods for the description of power system dynamic load models. Two classes of descriptive methods are discussed: description using state variables as descriptive variables (SD: state variable description); and description using power and voltage as descriptive variables (ID: input/output description). First, ID and SD are compared, and the advantages of SD in many types of power system analysis are demonstrated. Next, the transformation from ID to SD is explained. The significance of this transformation is discussed, and a method is illustrated for cases of high order linear and first order nonlinear models. The practicality and generality of the SD of load models indicated