Approximate 2-degree-of-freedom digital control for a boost DC-DC converter
If a duty ratio and a load resistance in a boost DC-DC converter are changed, the characteristics is varied greatly, that is, the boost DC-DC converter has the non-linear characteristics. In many applications of DC-DC converters, loads cannot be specified in advance, and they will be changed suddenly from no load to full load. The boost DC-DC converter used a conventional controller cannot suppress output voltage variation caused by large load change. In this paper an approximate 2-Degree-of-Freedom (2DOF) digital controller for suppressing the output voltage variation at sudden load change is proposed. This controller is actually implemented on a micro-processor and is connected to the boost DC-DC converter. Experimental results demonstrate that this type of digital controller is effective to suppress the variation.