Modelling and Control of Boost Isolated Push-Pull Bidirectional DC/DC Converters

In this paper, aiming at the problem of the boost isolated push-pull bidirectional DC/DC converter that the average value of the transmitted inductor current is zero in one switching cycle and cannot be directly described by the state space model, a modal average hierarchical modelling method is proposed, and a low-order uncoupled small signal mathematical model of the system is further established to realize the decoupling of the front and rear circuits. Then based on the pre-stage model of the converter, a dual closed-loop control system is established to control the clamp capacitor voltage. Next, based on the post-stage model, a post-stage single-voltage loop phase-shifting control system is shown to control the output voltage. Finally, based on simulation analysis, the parameters of the regulator are optimized to improve the dynamic and static performance of the system.