Table-Based Direct Power Control: A Critical Review for Microgrid Applications

Direct power control (DPC) has increasingly gained attention in the last years as a robust and simple control scheme. Yet, the implications of some of the assumptions made by the original table-based DPC are not well explained in the literature. Here, a new formulation of DPC is presented, that allows to analyze the shortcomings of this kind of algorithms, mainly regarding the power limits in which table-based algorithms are valid. This is a key aspect for microgrid applications, as they require a wide range of possible active and reactive power setpoints in order to be able to control the system´s voltage and frequency. A new table is then presented that allows to overcome those limitations. The proposed table is valid at any point of the inverter´s power limits.