The Research And Design Of Charge And Discharge For Battery Based On The Bidirectional DC-DC Conversion Techniques

With the rapid economic development and the innovation of science andtechnology, the battery is more and more widely used in these areas of aerospace,electric vehicles and uninterruptible power supplies(UPS). Therefore the study ofbattery charge-discharge technology is particularly important. The traditionalcharge and discharge device uses different circuits. While, the Bi-directionalDC-DC Converter researched in this article has the function of charge anddischarge, which achieves the effect of “one device with two functions”.Firstly, this paper introduces the current research situation of theBi-directional DC-DC Converter, and summarizes the converter modeling methodsand control technologies.Secondly, it describes the non-ideal converter circuit average-modelingmethod, and gives the small-signal model of buck and boost converter with thecontinuous current.Then, according to the system’s indicators, the paper presents the method ofdesign BUCK/BOOST Converter’s main circuit parameters, analyzes several kindof buffer circuit structures and points out their advantages and disadvantages.On the basis of comparison with previous proposed control strategies, thispaper proposes three composite control strategies.These strategies inherit the meritsof the traditional voltage control, current feedback control and feedforward control,which have the characteristics: strong anti-interference ability, fast response, andgood stability. The simulation models are built on the base of MATLAB software,simulation results indicate the effect of these proposed control strategies. At thesame time, this paper also studies the relations between system dynamic responseand system bandwidth when BUCK operates under constant-voltage situation, andgives the method to reasonable determine the bandwidth to achieve or close to theoptimal load dynamic response. Of course, the paper describes the function of eachpart of the double pole-double zero controller,and gives the basis to select thecontroller parameters.Finally, it introduces the prototype’s hardware circuit and software designingcarefully. Then a1400W bi-directional BUCK/BOOST DC-DC converter is achieved. The experiment waveforms testify that the theoretical analysis is correct.