Provision of Ancillary Service in a Grid-Connected Photovoltaic Power System

In this paper, is studied the provision of ancillary service (AS) of harmonic compensation of a distributed generation (DG) connected in a distribution network is studied, aiming at the improvement of power quality (PQ). This compensation is performed by operating the three-phase inverter, whose dc bus is connected to the photovoltaic (PV) generator, acting as active power filter (APF) and DG. One of the advantages of the proposed strategy is that the compensation is performed without the need to extract the harmonic components present in the current, which reduces the computational effort. For implementation the measured grid current is used as control variable. The control is based on the power balance between the grid and the inverter, and is carried out in the synchronous reference frame. A perturb and observe (P&O) algorithm is used for maximum power tracking, along with a control algorithm for dc bus voltage. To validate the study, experimental results were obtained from an experimental setup in three different scenarios.