The output characteristic of the photovoltaic array（PV） in photovoltaic-connected generating system is likely influenced by such factors as ambient temperature and sunshine intensity. The maximum power tracking and control are needed in order to improve the energy conversion efficiency of the PV module. In this paper

a kind of maximum power tracking method based on perturb & observation（P&O）method is proposed

which does not need to detect current at the DC side

but calculate the maximum power point by way of DC voltage and grid-connected current so to control the current and achieve the tracking of maximum power. This method avoids the use of DC current sensor and save the system cost. The correctness of the proposed method is verified by simulation and experiment.