Maximum power point tracking of grid-tied photovoltaic power systems

This paper presents high performance maximum power point tracking (MPPT) of a grid-tied PV power system via terminal sliding mode control (TSMC). Based on the proposed TSMC method, the output current of the grid-connected inverter is regulated to the maximum power point in finite time. Moreover, the inverter current is synchronized to the grid voltage, such that the current harmonic is reduced. In addition, the finite-time tracking performance of the TSMC improves the effectiveness of the maximum power point searching algorithm, so that the maximum power is correctly captured from the PV system in finite time. Also, the robustness to uncertainties and disturbances is guaranteed by the TSMC controller. No singular problem exists as similar as traditional TSMC control methods. The simulations and experiments have shown the expected performance.