Research On SOC Estimation Of Power Battery Based On Beetle Antennae Search And Central Differential Kalman Filter

In order to improve the performance of electric vehicles,the performance of battery packs needs to be further improved.Battery management system has an important effect on the performance of battery pack.In this paper,research object is SOC estimation method.Battery modeling and SOC estimation algorithm are two aspects.Firstly,a model of lithium ion batteries has been established.Based on a double piecewise equivalence circuit model an improved equivalent circuit model considering different charge-discharge model parameters was established by adding diodes to eliminate the theoretical errors caused by voltage lag in the dual polarization model.By fitting the soc-ocv curve with variable parameter double exponential function,the equivalent circuit sample of Jun ion battery can be obtained.Discrete models are obtained by discretization of the model.Then,the beetle antenna search algorithm is introduced.The algorithm is used for parameter identification.The simulation results are verified by parameter identification,and the simulation results show that the BAS algorithm has high accuracy above RLS and BCRLS.A central differential Kalman filter(CDKF)algorithm was introduced to the battery model.According to the characteristics of lithium iron phosphate batteries,A new SOC estimation algorithm is proposed.Then the algorithm is verified by matrab / SIMLINK simulation.In this paper,an improved cdkf estimation algorithm,i.e.high precision DST estimation,is proposed the maximum absolute error is less than 2%,the average absolute error is less than 0.3%.Finally,the hardware and software system to realize the actual vehicle SOC estimation algorithm are constructed,and the actual vehicle test is carried out.In cycle station,algorithm’s absolute error is less than 2%,algorithm’s average error is less than1%.When the discharge is very high,the terminal voltage of the battery changes greatly in the process of instantaneous high current pulse discharge.Therefore,the improved CDKF algorithm in this paper has a large instantaneous Errors can be corrected immediately.The result of Experimental show that our algorithm’s estimation and robustness is high.