Novel Model Reference-based Hybrid Decoupling Control of Multiport-isolated DC-DC Converter for Hydrogen Energy Storage System Integration

Hydrogen energy storage systems (HESS) are increasingly recognised for their role in sustainable energy ap plications, though their performance depends on efficient power electronic converter (PEC) interfaces. In this paper, a multiport-isolated DC-DC converter, characterised by enhanced power density, reduced component count, and minimal conversion stages, is implemented for HESS applications. However, the high-frequency multiwinding transformer in this converter introduces cross-coupling effects, complicating control and result ing in large power deviations from nominal values due to step changes on other ports, which adversely impact system performance. To address this issue, a novel model reference-based decoupling control technique is pro posed to minimise the error between the actual plant output and an ideal decoupling reference model, which represents the cross-coupling term. This model reference-based decoupling control is further extended into a hybrid decoupling control technique by integrating a decoupling matrix, achieving more robust decoupling across a wider operating region. The hybrid decoupling technique mathematically ensures an improved control performance, with the cross-coupling term minimised through a proportional-derivative controller. The proposed hybrid decoupling controller achieves a maximum power deviation.