Abstract:

This paper proposed a composite topology structure combining Buck and the full bridge,which can reduce the pressure of the switch tube and realize the topology change function when necessary.Then,according to the characteristics of digital controller,a double loop control method is adopted,in which voltage loop is the outer loop and current loop is the inner loop.The complex topology of Buck and full bridge is modeled,and the double loop control is added to the system for analysis and modeling.In order to verify the practicability of the complex topology and control method,MATLAB is used to analyze the designed topology and control in frequency and time domain.At the same time,the 300 W digital power supply is designed by using compound topology and double loop control method.Finally,the effectiveness and practicability of the compound topology and double loop control are proved.

Key words: composite topology, two loop control, digital control, Buck and full bridge