说明：  基于matlab 2010rb搭建的buck-boost chopper直流变换器升降压斩波电路仿真模型，调试通过，适合本科生学习电力电子技术仿真。
(2010 rb based on matlab to build the buck- boost chopper dc converter buck chopper circuit simulation model, debugging through, suitable for undergraduate study power electronic technology simulation.)