Single-stage MPPT control realization for Aalborg inverter in photovoltaic system

In this paper, the single-stage Maximum Power Point Tracking (MPPT) control strategy for the Aalborg photovoltaic inverter is presented. Aalborg inverter has many advantages, such as high efficiency, wide range of input voltage, minimum voltage drop of the filtering inductors, etc. Nevertheless, it is essentially a “half-bridge” inverter with two input sources, where one source works in MPPT mode, the other is out of control. If without the reasonable parameter design and the proper control, the bus-voltage of this inverter may change greatly, resulting in the serious power oscillation around maximum power point and the reduction of the energy utilization of PV array. In this paper, the MPPT algorithm of two independent PV arrays is proposed, and then the relation between ripple ratio and dc-link capacitance is analyzed. An 110V/50Hz prototype has been constructed. Simulations and experiments show that the proposed control strategy has good steady-state and dynamic performances.