Research On Control Technology Of Bidirectional DC/DC Convert For Super Capacitor Application

In recent years,the rapid development of new energy is given priority to distributed power,but renewable energy has great randomness and uncertainty,with the development of energy storage technology,energy storage carrier which is given priority to lithium battery and super capacitor has wide application in the distributed power generation and energy storage technology depends largely on the control of the converter.This paper,which is purposed to study the change characteristics of super capacitor voltage,focuses on control of bidirectional DC/DC converter when the super capacitor voltage changes largely,and the main research contents and results are as follows:At first,this paper introduces the basic theory of the linear matrix inequality(LMI)application,as well as the system performance indicators in the specification and description method about robust control.For linear time invariant system,it analyzes and gives the design methods of system state feedback control law;for linear time-varying system,it introduces the concept of multiple cell body model.In order to improve the dynamic performance,the pole assignment is introduced to design of the controller.Secondly,according to the operation mode of the bi-directional DC/DC circuit,this paper chooses the state space averaging method to establish model.Due to the change of the super capacitor voltage,according to multiple cell body model of convex optimization theory,this paper designs the different static working point in the model,so as to improve the stability when the system parameter changes.Thirdly,according to the multiple cell body model,the change of input voltage and load are considered in the model,this paper proposes a robust H-infinity controller.In order to improve the accuracy of state variable feedback,this paper measures inductance current by kalman filter to reduce the effects of noise.At last,aiming to test and verify the research content of this paper,a kind of simulation platform based on the MATLAB/Simulink and an experiment platform based on DSP TMS28335 are established.The related simulation and experimental validation are carried out.Through validation of the simulation and experiment,the proposed mathematical model and the correctness and effectiveness of the control method in this paper has been proved.And compared with traditional double loop PI controller,robust H-infinity controller not only shows the strong robustness,but also has good dynamic performance.