Recently a standard for testing maximum power point tracking (MPPT) algorithms was suggested that tests both step and ramp changes in irradiance. A new MPPT algorithm was developed to respond well to this standard input for various photovoltaic modules. The algorithm is introduced in steps showing the motivation for each step taken in the development of the algorithm. After this, the effects of converter losses on the MPPT algorithm will be explored. It will be seen that so long as the losses are not too great, the effects are minor. A subsequent paper will show the results from a practical implementation of this algorithm. (C) 2012 Elsevier Ltd. All rights reserved.