Grid-Following Voltage Source Converters: Basic Schemes and Current Control Techniques to Operate With Unbalanced Voltage Conditions

The growing relevance of voltage source converters (VSCs), and the deep impact they have on development maintenance electrical grid, increase necessity further research how to deal with nonideal grid conditions from VSCs control. This paper is aimed summarize basic techniques schemes that might be required for a grid-connected VSC work under these conditions: synchronization schemes, sequence decomposition, current reference generation, controllers. At same time, some alternative improves ones are cited. Modelling two typical controllers design tuning stationary synchronous frames also exhibited. Given importance control stage in behaviour, five designed track negative currents, shown tested simulation experiments. According experiments, it standard proportional-resonant controller achieves best performance tracking due robustness its non-ideal version, improved implementation thanks delta operator, non-dependence grid-synchronization schemes. Alternatively, one approach based dual frame highlighted easiness good performance.