This paper presents a new generator differential protection scheme based on phaselet. Analysis shows that phaselet algorithm can enlarge the harmonic current than Fourier algorithm. When internal faults occurs

the harmonic currents are different in two sides which can be used to improve the performance of the differential protection. Because the fault has the different influences on the different branches

the harmonic currents in the branches will be greatly different. The uncompleted differential protection and the split-phase transverse differential protection are composed of different branches

so they can obtain high sensitivity and reliability with phaselet algorithm. For large generator

the fault current will be greater

causing current transformer saturation which affects the protection performance. Research results show that the new scheme could get high performance at different conditions even when the current transformer is saturated.