Adaptive saturation scheme for a multifunctional single-phase photovoltaic inverter

Power inverters are essential components of photovoltaic systems and are designed to process the rated power generated by solar plant. Due to variations in solar irradiance, inverters have a current margin, which can be used in reactive power and harmonics compensation. This possibility, known as multifunctional operation, can be interesting in terms of power factor improvement and voltage control at point of common couple (PCC). Many works propose control strategies for multifunctional inverters. However, during multifunctional operation current limit of the inverter cannot be exceeded. Therefore, inverter needs to compensate partially reactive power and harmonics of the load. This fact is few related in literature. This work proposes a scheme of current dynamic saturation in order to compensate partially reactive power and harmonics of the load. This scheme is based on peak detection algorithm and prioritizes reactive power compensation. Conservative Power Theory (CPT) is used to separate the load current components. Simulation results show performance of the proposed dynamic saturation technique, providing adequate operation of the inverter and partial compensation.