The unbalanced impedance of the asymmetric 3-phase wind power permanent magnet synchronous generator(PMSG)compensated by external circuits in series with the 3-phase windings is investigated in this paper.The asymmetr...The unbalanced impedance of the asymmetric 3-phase wind power permanent magnet synchronous generator(PMSG)compensated by external circuits in series with the 3-phase windings is investigated in this paper.The asymmetric impedance includes the unbalanced resistances,unbalanced self-inductances,and unbalanced mutual inductances.From the perspective of the second harmonic inductances in dq-frame and from the perspective of the second harmonic power,it is theoretically demonstrated that the original asymmetric 3-phase system with asymmetric impedance can be modified to a balanced system by external circuits consisting of resistances and inductances.Therefore,the second harmonic power and DC bus voltage due to the asymmetries can be suppressed naturally without any software modifications.The feasibility of this compensation method is validated by elaborate experiments at different speeds and under different load condition,although the effectiveness might be slightly affected by the non-linearity of the compensation inductance in practice.展开更多
This report describes the procedure of a case in which the skin paddle of the free fibula flap derived its supply solely from a soleal musculocutaneous perforator originating from the posterior tibial system.In contra...This report describes the procedure of a case in which the skin paddle of the free fibula flap derived its supply solely from a soleal musculocutaneous perforator originating from the posterior tibial system.In contrast,the osteo-muscular component was supplied by the peroneal vascular system.We harvested the skin paddle with its vascular supply from the posterior tibial artery separately,and the osteo-muscular fibula was harvested with its supply from peroneal vessels.In this way,we avoided violation of the second donor site for the skin paddle.In addition,we used the distal end of peroneal vessels to salvage our skin paddle instead of sacrificing another set of neck vessels for anastomosis.This technique may also be utilised in cases where the neck vessels may not be available due to previous surgeries,radiation therapy,or decision by the surgery team to not sacrifice two sets of neck vessels for anastomosis.展开更多
文摘The unbalanced impedance of the asymmetric 3-phase wind power permanent magnet synchronous generator(PMSG)compensated by external circuits in series with the 3-phase windings is investigated in this paper.The asymmetric impedance includes the unbalanced resistances,unbalanced self-inductances,and unbalanced mutual inductances.From the perspective of the second harmonic inductances in dq-frame and from the perspective of the second harmonic power,it is theoretically demonstrated that the original asymmetric 3-phase system with asymmetric impedance can be modified to a balanced system by external circuits consisting of resistances and inductances.Therefore,the second harmonic power and DC bus voltage due to the asymmetries can be suppressed naturally without any software modifications.The feasibility of this compensation method is validated by elaborate experiments at different speeds and under different load condition,although the effectiveness might be slightly affected by the non-linearity of the compensation inductance in practice.
文摘This report describes the procedure of a case in which the skin paddle of the free fibula flap derived its supply solely from a soleal musculocutaneous perforator originating from the posterior tibial system.In contrast,the osteo-muscular component was supplied by the peroneal vascular system.We harvested the skin paddle with its vascular supply from the posterior tibial artery separately,and the osteo-muscular fibula was harvested with its supply from peroneal vessels.In this way,we avoided violation of the second donor site for the skin paddle.In addition,we used the distal end of peroneal vessels to salvage our skin paddle instead of sacrificing another set of neck vessels for anastomosis.This technique may also be utilised in cases where the neck vessels may not be available due to previous surgeries,radiation therapy,or decision by the surgery team to not sacrifice two sets of neck vessels for anastomosis.