Output controllability of switched power converters as switched linear systems

Output controllability (OC) is the basic characteristics of any control systems, but OC of switched power converters has not been studied yet. Switched linear systems (SLS) theory was introduced to OC study of switched power converters in this paper. At first, basic switched power converters, such as basic DC-DC converters, were built as switched linear system models. Then according to the characteristics of switched linear system models of power converters, the OC definition and its sufficient and necessary criterion of switched linear systems was presented. At last, the OC analysis of buck converter and boost converter was given. The analysis results verify that the basic DC-DC converters are output controllable based on switched linear system model and so modern control methods could be used to control and regulate power converters´ output. The analysis method can be extended to other switched power converters or control systems. Buck converter with load current step decrease and increase was implemented as an example to illustrate the output controllability of switched power converters.