Comparison of MPPT strategies applied in three-phase photovoltaic inverters during harmonic current compensation

The main objective of a photovoltaic (PV) inverter is to inject the PV power into the ac-grid. Generally, due to variations in solar irradiance, inverters operate bellow their rated current. Therefore, this current margin can be used to ancillary services, such as harmonic current compensation. However, it is necessary to evaluate the effects of the harmonic current compensation in the efficiency of the algorithms of maximum power point tracking (MPPT). In this context, this work compares, based on the European Standard, the instantaneous and dynamic efficiency of four MPPT algorithms used in photovoltaic systems: perturb and observe, dP - perturb and observe, modified perturb and observe and incremental conductance. The instantaneous power theory (IPT) is used to detect the harmonic current. Simulation results show the instantaneous and dynamic efficiency of MPPT algorithms during rapidly irradiance changes and harmonic compensation. According to the results, it can be concluded that the proposed multifunctional inverter has a slightly impact in the efficiency of the maximum power point algorithms.