Disturbance Compensation-Based Discrete Single-Phase-Shift Control for DAB DC-DC Converter

A novel disturbance compensation-based discrete single-phase-shift (DCB-DSPS) control strategy is proposed in this paper to improve the dynamic performance of dual-active-bridge (DAB) dc-dc converter. In the proposed control strategy, the phase-shift ratio consists of two components. The first component is the open-loop phase-shift ratio
d
_ol
of the DAB dc-dc converter under SPS modulation, which can be easily calculated using a digital signal processor. The second component is compensated phase-shift ratio, which is selected from preset discrete values Δ
d
_H
and Δ
d
_L
according to the relationship between reference value and sampled value of output voltage. The compensated phase-shift ratio is utilized to eliminate steady-state error caused by non-ideal parasitic parameters and disturbances in the source, load, and controller, ensuring accurate regulation of the output voltage to track the reference voltage. Therefore, by directly generating discrete control phase-shift ratio, the proposed DCB-DSPS control can achieve accurate and fast adjustment of the output voltage under both input voltage and load step change. The control principle, parameters design and control performance analysis of the proposed DCB-DSPS control strategy are presented and validated on a 96V-48V/260W-50kHz DAB dc-dc converter experimental platform.