Research Of Non Isolated Bidirectional DC-DC Converter Based On The Fuzzy PID Controller

With the global energy crisis intensified and the development of the entire automotive industry,pure electric vehicles will become the leading trend of the mainstream products.As the key component of energy management system,DC-DC converter has a high demand for its weight,volume,reliability and efficiency.As a fuel cell or battery,the bidirectional DC-DC converter is the key component to realize the energy management.In the electric vehicle energy management control system,when the electric vehicle motor needs battery power supply,the bi-directional DC-DC converter through the high voltage output of the battery to provide high speed motor operation;When the battery feed capacity,the voltage can be reduced by the bidirectional DC-DC converter,so that the storage battery is in the state of charge and the excess energy is recovered to achieve the purpose of energy saving.The bidirectional DC-DC converter realizes the integration of charging and discharging,optimizes the motor control of the electric vehicle,and improves the operation efficiency and performance of the vehicle.For electric vehicles,the output voltage value of the battery with the battery capacity(SOC)decreased gradually reduced.The bidirectional DC-DC converter can stabilize the voltage value of the preset value after the voltage transformation,and can prolong the service life of the battery of the electric vehicle to a great extent.Therefore,the use of advanced intelligent control strategy for bi-directional DC-DC converter has very important use value and scientific significance.Firstly,in this paper,the classical converter topology is introduced,and the research status of bidirectional DC-DC converter is analyzed.The working principle of non-isolated bidirectional DC-DC converter is explained.The design of the single voltage closed loop parameters of the whole circuit is studied.Based on the state space average method,the transfer function model of the bi-directional DC-DC converter system is established.Secondly,this paper presents a simple structure and excellent performance of the non isolated bidirectional DC-DC converter topology,at the same time,the design of PID controller,fuzzy controller and fuzzy PID controller,and the simulation experiment of the controller and the model in matlab/simulink,validate the validity of the controller and the control effect of the three kinds of control strategy the performance is compared.Finally,this paper designs a reasonable hardware circuit and software design.The hardware circuit design includes the main circuit,the driving circuit,the voltage sampling circuit and the power supply circuit.The software design includes the main program design,the fuzzy PID controller subroutine,the EPWM module configuration subroutine And ADC module configuration subroutine.The prototype experiment was carried out,and the related test and result analysis were carried out to verify the effectiveness of the proposed algorithm and the converter.