This paper analyzes three different current phase compensation methods used in transformer differential protections for identifying inrush current when transformer is energized on no-load. It shows that these three current compensation methods have similar effect on identifying inrush current. According to this， a new algorithm for integrating these three current compensation methods based on fuzzy logic is proposed. By appropriately selecting the membership function of the second harmonic in three-phase differential current， the membership grades in case of different current compensation methods are obtained， then the integrated membership grade are acquired. Using the two-out-of-three principle which is based on the integrated membership grade， this new algorithm improves the reliability of transformer protection in blocking inrush current. Results of dynamic simulation and the analysis of field case show that the scheme for second harmonic blocking is effective and proper.