Weighted controller structure of DC-DC converters for adaptive regulation to large-signal operations

Abstract

A weighted controller structure for DC-DC converters is proposed to deal with large-signal operations. For wide range variations of input voltage and load conditions of DC-DC converters, we firstly divide the pre-defined global operation space into local subspaces where each local linear compensator is designed for the corresponding subspace, and then all the local linear compensators are weighted into single controller structure. By doing so, the weighted controller can automatically decide which local linear compensator regulates the dynamics of DC-DC converter according to the operation conditions, and thus has the capability of self-adaptation to wide range of operating point variations. Furthermore, the prominent feature underlying the weighted control scheme is also that the nonlinearities of DC-DC converters is easily to be handled by linear compensation approaches that can be easily implemented with analog or digital control circuitries. To demonstrate the effectiveness of this controller structure, a stand-alone DC-DC converter and a cascaded DC-DC converter system are taken as examples by simulation and experimental results.