软开关PWMboost全桥变换器_英文_.docVIP

Journal of Southeast University ( English Edition ) Vol. 19 No. 3 Sept . 2003 ISSN 1003 7985 Soft switching PWM boost full bridge converter Zhou Linquan Ruan Xinbo ( College of Automation Engineering, Nanj ing Univers ity of Aeronaut ics and Ast ronauti cs , Nanj ing 21 0016, Ch ina) Abstract: T his paper prop os es a f am il y of PWM modu lat ion st rategi es for b oost f ul l bri dge ( FB) convert ers. Th e mod ul at ion s trat egi es can b e cl as sif ied int o two k inds accordin g t o t he t urn on s equence of t h e d iagon al sw it ches . Th e concept of lead ing sw it ches and l agg ing sw it ches is int rod uced t o realiz e sof t sw it ch ing. According t o t he s oft sw it chi ng real ized by th e leading sw it ch es and t he lagg ing sw it ches, tw o k ind s of s of t sw it chin g t ech niq ues f or PWM boost FB convert ers yi eld: z ero curr ent sw it ch ing ( ZCS ) and zero cu rrent and zero volt age sw itch ing ( ZCZVS ) . Sim ulat ion resu lts ver ify t he analys is. Key words: PWM; b oost ; ful l bridge convert ers; zero current sw itching; z ero volt age sw it ch ing  The isolat ed buck full bridge ( FB) convert er is widely u sed in med ium and h igh power sup plies due to its simp le con st ru ction , low cost an d h igh reliab il ity. Its topologies and modu lation strategies , esp ecially its soft switch ing modu lation strat egies, have been [ 1- 3] I in is constant , an d the transformer is ideal. By modulat ing the four swit ches Q1 to Q4 , t he primary cu rrent i p is an AC squ are current, the amp litu de of wh ich is I in . A s econdary current app ears, and is rect ified to i rect by the output rect if ier diodes DR1 and ext ens ively research ed . T he isolat ed boost FB converter is attractive in applications su ch as s ingle stage power factor correct ion ( PFC