In this paper a method to perform maximum power tracking on isolated PV systems without energy storage is proposed. Initially, numerical simulations are performed for a PV system composed of an array of panels, a DC/DC converter and a single-phase power inverter feeding a resistive load. Results under load variations show the need of performing power tracking to achieve the demand supply. Moreover, in order to keep a proper operation of the power inverter a DC-link voltage control is also performed by an improved power tracking method combining a P&O algorithm and a PI regulation loop. The proposed algorithm shows an acceptable performance to keep power delivery under environmental variations. This method seems to be effective to PV systems in stand-alone applications. Ongoing work is currently devoted to perform experimental validation of the numerical results presented.