A generalized single-phase multilevel current source inverter (MCSI) topology with self-balancing current is proposed, which uses the duality transformation from the generalized multilevel voltage source inverter (MVS...A generalized single-phase multilevel current source inverter (MCSI) topology with self-balancing current is proposed, which uses the duality transformation from the generalized multilevel voltage source inverter (MVSI) topology. The existing single-phase 8-and 6-switch 5-level current source inverters (CSIs) can be derived from this generalized MCSI topology. In the proposed topology, each intermediate DC-link current level can be balanced automatically without adding any external circuits; thus, a true multilevel structure is provided. Moreover, owing to the dual relationship, many research results relating to the op- eration, modulation, and control strategies of MVSIs can be applied directly to the MCSIs. Some simulation results are presented to verify the proposed MCSI topology.展开更多
The synthesis of cycloheptanoid-based fused polycyclic frameworks is a challenge for organic chemists due to unfavorable entropic factors and ring strains.Herein,a concise synthesis of 4-desmethyl-rippertenol and 7-ep...The synthesis of cycloheptanoid-based fused polycyclic frameworks is a challenge for organic chemists due to unfavorable entropic factors and ring strains.Herein,a concise synthesis of 4-desmethyl-rippertenol and 7-epi-rippertenol bearing a unique,[6,6,5,7]-fused tetracyclic framework is reported.The route features a novel photoinduced intramolecular cyclization ofα-cyclopropyl dienone followed by an unexpected thermal 1,5-hydrogen migration.展开更多
文摘A generalized single-phase multilevel current source inverter (MCSI) topology with self-balancing current is proposed, which uses the duality transformation from the generalized multilevel voltage source inverter (MVSI) topology. The existing single-phase 8-and 6-switch 5-level current source inverters (CSIs) can be derived from this generalized MCSI topology. In the proposed topology, each intermediate DC-link current level can be balanced automatically without adding any external circuits; thus, a true multilevel structure is provided. Moreover, owing to the dual relationship, many research results relating to the op- eration, modulation, and control strategies of MVSIs can be applied directly to the MCSIs. Some simulation results are presented to verify the proposed MCSI topology.
基金supported by the National Key Research and Development Program of China(grant no.2018YFC0310905)the National Science Foundation of China(grant nos.21632002,21871012,and 21801123)the Shenzhen Basic Research Program(grant nos.JCYJ20180302180215524 and JCYJ20170818091450164).
文摘The synthesis of cycloheptanoid-based fused polycyclic frameworks is a challenge for organic chemists due to unfavorable entropic factors and ring strains.Herein,a concise synthesis of 4-desmethyl-rippertenol and 7-epi-rippertenol bearing a unique,[6,6,5,7]-fused tetracyclic framework is reported.The route features a novel photoinduced intramolecular cyclization ofα-cyclopropyl dienone followed by an unexpected thermal 1,5-hydrogen migration.
