Severe defects existing on stator winding bars had been discovered in operation of generator no.2 in one power,after retrofits,such as replacement of stator winding bars,and improvement of their fixed mode etc.,the defects still hadn't effectively eliminated.Based on summation and analysis of defects existing in the generator and causes of ineffective retrofit,three measures for defect-eliminating and capacity-increasing retrofit have been put forward,and the feasibility of said three methods being compared in detail,to determine the retrofit scheme.