Abstract: The maximum power point tracking（MPPT）technology of the photovoltaic power generation

system is the great significance to ensure the output efficiency of the photovoltaic power generation system and the

stability of the system. An MPPT control algorithm was proposed based on an improved conductance increment

method，which modified the step change by a coefficient related to the current to decrease the influence of the current change on the output characteristics of the photovoltaic cell. Then，based on the technique for order preference by similarity to an ideal solution（TOPSIS）method，six evaluation indicators were constructed to evaluate three different coefficient schemes，and then determined the optimal variable step size coefficient. The simulation of the MPPT model and the TOPSIS calculation show that by using 1/I 2 as the correction coefficient to correct the dP/dU instead of the fixed step size parameter，the obtainedMPPT control algorithm has integrated tracking performance.

      Key words: photovoltaic power generation；maximum power point tracking（MPPT）；conductance increment

method ；variable step size ；technique for order preference by similarity to an ideal solution（TOPSIS）method