On the equivalent ZIP parameter extraction of desktop computer cases and LCD monitors connected in parallel

Abstract

Constant-impedance, constant-current and constant-power ZIP models of electrical loads are commonly used in smart grid and residential load applications. Some of residential loads are of nonlinear nature such as LCD monitors and computers. In this study, first, equivalent ZIP model formulas of parallel-connected electrical loads are derived. Then, the ZIP models of an LCD monitor, a computer case and the computer case and the monitor connected in parallel have been obtained using experimental data and least-squares curve fitting method. Finally, the equivalent ZIP model formulas are tested with the experimental data. It has been found that for the rectifier nonlinear loads with different ZIP parameters, the formulas do not give acceptable errors. Therefore, for rectifier nonlinear loads, the measurement-based approach for load modeling must be performed.