DC-DC converters were considered as one type hybrid dynamic systems (HDS)-switched linear systems (SLS) and the concept of switched linear systems was introduced to DC-DC converter controlled systems.Based on systematical model

output controllability (OC) of DC-DC converters was studied which provides the basis of modern control method application in DC-DC converters.At first

the concept of switched linear systems was introduced and the basic DC-DC converters were built as switched linear system models.Then the output controllability definition and its sufficient and necessary criterion for switched linear systems were given.At last

the output controllability of basic DC-DC converters was analyzed.The simulation analysis and experimental verification of output controllability for Buck converter was given as an example.The analysis method of output controllability for DC-DC converters could be extended to other power converters or all switched circuit to study the output controllability.