| As a good performance energy storage component,lithium-ion batteries play an important role in alleviating the global energy crisis and combating climate change.Power electronic devices contain a large amount of high-frequency ripple in the current when charging and discharging lithium-ion batteries.It is important to study the characteristics of lithium-ion batteries under high-frequency ripple current.This can promote the development of battery energy storage technology.At present,there is no test equipment available in the market to study the effect of such high frequency ripple current on the characteristics of lithium-ion batteries.In this thesis,we design a lithium-ion battery high-frequency characteristic test platform with DSP28335 as the core.The output frequency of the platform can be adjusted in the range of 1 k Hz to 10 k Hz.The maximum DC current is 100 A,and a current with a certain amplitude ripple can be superimposed.The main work of this thesis is as follows.Firstly,the overall scheme design of the platform was carried out.By comparing the bidirectional Buck-Boost converter with the bidirectional full-bridge converter,the bidirectional full-bridge converter was selected as the main circuit topology.The total ripple distortion rate THD(Total Harmonics Distortion)of the output current was analyzed,and the high-voltage side voltage range was determined in this way.The size of the inductor value was determined based on the experimental requirements of the Li-ion titanate battery.The IGBT selection was carried out and the IGBT buffer circuit was designed.The main circuit simulation model was built and verified.Secondly,the hardware design of the control circuit was carried out.DSP28335 was selected as the main control chip,and the design of signal detection circuit,signal conditioning circuit,CAN communication interface circuit and protection circuit were completed.Analyzed the driving requirements of the IGBT and completed the design of the driving circuit based on M57962 L.The fast protection of the hardware circuit was realized by CPLD.Then,according to the functional requirements of the platform,the design framework of the software program was given and the DSP program was written;the upper computer program design was carried out using Python language to realize the real-time observation of experimental data and the modification of experimental conditions parameters.Finally,an experimental prototype was built and experiments were conducted at the required frequency to verify the feasibility of the design of the main circuit,driver circuit and buffer circuit of the platform.The experimental results showed that the platform can achieve the output of the target charging and discharging current. |
