Study On Port Voltage Setting Technology Of Power Battery Analog Power Supply

Since 1950,problems such as energy crisis and environmental pollution have become increasingly prominent.In order to cope with the current problems,governments around the world have developed new energy vehicles one after another,and electric vehicles are the focus of development.In the face of the electric car boom,major manufacturers are bound to improve the efficiency of the R&D test platform in order to shorten the development cycle.The key component of the test platform is the power battery,but the direct use of the battery has some shortcomings such as high cost,high loss and long charging and discharging cycle.But how to make the battery analog power supply track the voltage characteristics of the battery port with high performance is still a difficult problem.In this paper,the port voltage setting technology of power battery analog power supply is studied,and the related work is done in the aspects of SOC estimation,port voltage setting method and real experiment.Firstly,in order to improve the accuracy of power battery simulation of the given power supply voltage,an Improved Extended Kalman Filter(IEKF)is used to estimate the SOC of the battery.Accurate SOC estimation is a prerequisite for the battery to simulate the given voltage of the power supply.In order to solve the problems of unstable estimation results caused by uncertain initial estimation values and inaccurate model parameters,a power battery SOC estimation method based on IEKF was proposed.The method uses the identified parameters to reconstruct the update equation of state variables,which solves the problem that multiple iterations are needed due to the uncertainty of initial estimation.The difference between the model predicted voltage and the sampling voltage is used as the threshold,and the ampere-hour method and the EKF method are switched to improve the estimation accuracy of the EKF method alone.The simulation results show that the proposed method has higher accuracy and better stability than the EKF algorithm.Secondly,a table lookup algorithm of successive nearest neighbor interpolation is proposed to determine the given voltage of the battery analog power supply in order to give consideration to the real-time,realizability and the accuracy of the given voltage.The method according to the power battery SOC in the initial period,stable period and at the end of the period of the output characteristics of three different resolution model child table,and draw lessons from the neighboring interpolation algorithm is of the advantages of small amount of calculation and easy to implement and use table partitioning of successive iteration of the model,then approximation and the actual SOC and sampling current corresponding battery model for a given voltage,refining the battery model table resolution.The influence of iteration number selection on the accuracy of the algorithm is discussed,and different sampling ratios are used to reduce the data capacity of the model.A large number of experiments are carried out on data tables with different capacity.The experimental results show that the proposed method can maintain high accuracy under the condition of low resolution data samples.Finally,a power electronics experimental platform with bidirectional DC/DC as the main circuit and TMS320F28335 as the main control chip is built.The algorithm in this paper is programmed in the CCS development environment,which verifies the realization of the algorithm in the physical platform and lays a foundation for the practical application.