Power Quality Assessment of Power Systems with PV Sources Using Discrete Equivalent Models

This article describes the application of a method for the power quality and stability assessment in time-domain (TD). This method consists of the combination of companion-circuit analysis (CCA) through the Trapezoidal Rule (TR), and a sparse matrix factorization technique based on a Lower-Upper (LU) decomposition process, which results in the CCA TR -LU method. The CCA TR modeling allows, to obtain a conductance matrix (symmetric and sparse). The CCA TR -LU method potential is demonstrated through the application to different case studies oriented to power quality adverse phenomena assessment, taking as a reference the modified IEEE 30- bus test system under fault conditions, as well as the impact associated with the connection of a PV source. In terms of accuracy, the results of the case studies have been validated obtaining a close agreement compared against the PSCAD/EMTDC® response.