It is still an important problem to realize the optimal economical dispatch operation of series-type microgrids with capacity constraints in a communication-free manner. To address this problem, a new optimal economical dispatch control scheme is introduced for the islanded series-type microgrids without communications. There are two prominent advantages: (1) global optimal economical operation with capacity constraints is realized and (2) improved load voltage quality is obtained. Then, the stability of the introduced scheme has been analyzed with small-signal analysis method. Finally, the effectiveness of the method is verified by both simulations and experiments.