A novel approach to dynamic load modelling

A novel approach is proposed for the dynamic modelling of electric power loads in which the parameters of the equivalent single-unit model are estimated with a constrained nonlinear recursive filter (CNLRF) based on the data obtained from field tests. No prior knowledge of the values of individual load parameters or the iterative solution of the state equations is required. The algorithm is validated by applying it to an industrial load of 30 MW supplied by two 115 kV feeders. The industrial load is mostly rotating machines, consisting principally of motors of various sizes. The load responses were recorded during sudden voltage dips. The simulated results obtained with the nonlinear composite model developed in the paper are very close to those recorded from field tests, while the linearized model exhibits larger error in the case of bigger voltage dips