The Open Electrical & Electronic Engineering Journal

2017, 11 : 57-67
Published online 2017 February 28. DOI: 10.2174/1874129001711010057
Publisher ID: TOEEJ-11-57

RESEARCH ARTICLE
 Modeling and Controlling Strategy of Four-Switch Buck-boost Convertor with Smooth Mode Transitions

Wei-zhong Zhang1,2, * , Hui-pin Lin3 , Yao Zhang2 and Ji-min Jin2

* Address correspondence to this author at the School of Mechanical Engineering and Automation, Zhejiang SCI-TECH University, Hangzhou 310018, China; Tel/Fax: (086)0571-87773023; E-mail: zwz_ly@163.com

ABSTRACT

Four-switch synchronous buck-boost (FSBB) converter is much suitable for battery management system for its characteristic of wide input voltage range, high efficiency, and positive voltage output. A three mode control scheme with two modulation signals and one carrier can be adopted to achieve the smooth transition among modes. Using feed forward voltage mode control, the input voltage information is injected into the control loop to prevent the disturbance effect on the output voltage through making input voltage construct the carrier signal. High efficiency is gained when the converter is operating in pulse skip mode in light load. The operating mode smooth transition and stability could be achieved by modeling the converter and designing the compensation. Finally, a power prototype was fabricated to validate the validity of the control strategy.

Keywords:

Four-switch synchronous buck-boost converter, Wide input voltage range, Three-mode smooth transition, Feed forward voltage mode control, Buck-boost (FSBB), SEPIC.