Research On Control Strategy Of Multiple Bidirectional Buck/Boost Converter

In order to improve the dynamic response and anti-interference ability of the energy storage system,it is very important to improve the performance of the bidirectional DC-DC converter.In addition to the study of its topology,the control strategy can also be studied in depth so that it can adapt to more stringent requirements.Therefore,it is of practical significance to study the control strategy of multiple bidirectional Buck/Boost converters.Based on the theory of automatic control,a hybrid control strategy based on feedforward correction is proposed on the basis of the dual closed loop feedback control strategy based on the three double bidirectional Buck/Boost converter.The paper first analyzes the working principle of the two modes of the three bi-directional Buck/Boost converter,and uses the basic modeling method to establish the AC small signal model in the Buck and Boost modes,in order to ensure that the three double bidirectional Buck/Boost converter has a better dynamic and steady state characteristics and prevents the circulation between the branches.In this paper,a two closed loop feedback control strategy based on current inner loop independent control is adopted.Through simulation analysis,it is concluded that the feedback control strategy can not meet the requirements because of its structural constraints.In order to solve this problem,a basis for solving this problem is proposed.A hybrid control strategy for feedforward correction.On the basis of the feasibility of the theoretical analysis of the compound control strategy,the feedforward compensation network is designed,and the system simulation model under two control strategies is built by Matlab/Simulink.The simulation experiment is carried out,and the simulation results are compared,and the superiority of the proposed control strategy is preliminarily verified.In order to further verify the correctness of the proposed control strategy,an experimental prototype of the three bi-directional Buck/Boost converter is designed and made,and the experimental results show that,in the case of no increase in overshoot,the three bi-directional Buck/Boost transformation based on feedforward control strategy is adopted in comparison with the feedback control strategy.The dynamic response time of the converter is shortened by nearly 1/2,which verifies the rationality and superiority of the proposed control strategy and achieves the desired effect.