Briefly introduce the former study of chaos and the common method of chaos modeling . ( 2 ) some discrete - time maps based on different switching mode are summarized and analytical expressions suitable for general dc / dc converters are present ( 2 )对几种基于不同切换方式的离散映射进行归纳总结,得到适合一般dc / dc变换器精确建模的解析表达式,同时总结了混沌现象研究的常用工具。