Sampled-Data Model of a Two-Phase, Dual Interleaved Buck–Boost Converter With PCM

Abstract

A sample-data modeling strategy for a 30-kW, two-phase dual interleaved buck–boost converter with peak current control is analyzed in this article. A small-signal converter model is derived to characterize the system utilizing the current peaks of the two interleaved phases and a half-symmetry, state-space representation of the circuit. The model is experimentally verified using a 32-kW, 350-V prototype that owns 7.6 kW/kg and 97.1% of power density and efficiency, respectively. A description of the controller, developed in a high-performance microcontroller, is also presented together with the experimental verification, detailing the design of the compensating ramp for a wide load range. Measured results are contrasted with the sample-data model predictions, using both transient and frequency responses, and evaluating the controlled converter dynamics at 14, 21, 26, and 30 kW. The comparison reveals the effective validity of the presented sample-data model and the effects of the supply to the dynamic performance of the high-density converter.