Study on Online Intelligent Recognition and Evaluation Method of SOC and SOH Of Battery Pack for Electric Vehicle Based on Driving Cycle Characteristice

SOC(state of charge) and SOH(state of health) of battery pack are the key parameters for the battery and energy management system of electric vehicles.And a precise calculation model is difficult to be built for their many influencing factors such as the battery cell characteristics,consistency of the battery pack and equalization technology etc.Based on the real driving cycle statistical data of the electric vehicles about battery pack output,an improved Ah integral method is proposed to calculate the SOC and SOH of battery pack,which adopts the cycle capacity and equivalent cycle current in the Peukert equation to achieve homeostatic capacity correction.Meanwhile fuzzy logic is adopted to achieve the dynamic capacity correction for discharge rate fluctuations. A more comprehensive method for state evaluation of battery pack is proposed by using SOC and SOH distribution array of battery cells.Ultimately,the rationality and practicality is verified by simulation calculation.