Improved dynamic performance of dual active bridge dc-dc converters using MPC scheme

Dynamic performance is a key focus of power conversion systems for facing with input and output step-change and disturbance cases. To improve dynamic characteristic of dual-active-bridge dc-dc converters, this study proposes a non-linear model predictive control (MPC) scheme with phase-shift ratio compensation to face with the following extreme conditions: start-up or step change of load resistance, input voltage, and the desired output voltage. Furthermore, in view of the idea of direct current control, MPC scheme using fewer sensors is proposed, which greatly increases the flexibility of control system and reduce the cost. Compared to traditional voltage closed-loop (TVCL) control and model-based phase shift (MPS) control, the salient features of the proposed MPC can be summarised as excellent dynamic performance, weak parameter sensitiveness, in addition, it is also available and effective when the load current sensor is not used. Finally, three control schemes consisting of TVCL, MPS, and the proposed MPC scheme are compared and tested in a scale-down experimental prototype. The above excellent performance of the proposed MPC scheme has been verified by experimental results.