等效电源 T2 T SO 3s5 I 2 m+ m(sin at +sin 3at+-sin5at+..) 3 5 SO s5 S s 3sin5 ) 5 1 sin3 3 1 (sin 2 2 = + t + t + t + I I i m m S     t T/2 T S i I m IS0 s1 i s3 i s5 i IS0 s1 i s3 i s5 i 等效电源