Estimation of parameterized nonlinear loads: A time-domain approach

This paper presents the study and development of a parameterized model for nonlinear loads, which are presented in the majority of electronic equipments available in the market. The nonlinear loads are represented by a bridge rectifier with an input inductor L modeling the EMI input filter inductance, an output filter capacitor C and an equivalent resistive load R connected in parallel. The L, C and R parameters are determined from voltage and current data acquisition through a discretization based-algorithm (applying the concept of discrete approximations). As a result, a circuit network can be obtained from the knowledge of the linear and nonlinear electrical system parameters, allowing a time-domain analysis via simulators such as ATP, PSIM©, Matlab/Simulink© and PSPICE©. Therefore, many aspects of the influence of these nonlinear loads over a given electrical installation can be studied such as power factor, displacement factor and harmonic distortion, allowing a power quality analysis.