Design of H∞ Robust Controller With Load-Current Feedforward for Dual-Active-Bridge DC-DC Converters Considering Parameters Uncertainty

This paper proposes the design of H∞ robust controller with load-current feedforward for dual-active-bridge (DAB) dc-dc converters used in battery energy storage systems, aiming to ensure the dynamic response considering parameters uncertainty that the input voltage varies in a large range and the load is uncertain. Firstly, according to the state-space representation based on dual-phase-shift (DPS) control, a polytopic model of the DAB converter with two uncertain elements is established by convex optimization theory. Based on this model, linear matrix inequalities (LMIs) are then used to design the H∞ robust controller conveniently to minimize the influence of parameters uncertainty disturbance on the output voltage. At the same time, a regional closed-loop pole configuration technique is used to guarantee the dynamic response of the system under a wide range of operating conditions. Furthermore, an improved load-current feedforward control with lookup tables for phase-shift compensation is adopted to further enhance the dynamic response. Finally, an OPAL-RT hardware-in-loop platform with Texas Instruments TMS320F28377D microcontroller is used to verify the feasibility and effectiveness of the proposed H∞ robust controller.