Study On The Key Technology Of The Residual Capacity Of Retarded Power Battery

As environmental issues are concerned by more countries,new energy vehicles continue to be developed and generalized in more countries.As a important part of new energy automotive industry chain,except for power batteries with a better performance,the exploration of recycling and reuse model has become a issue,which can be not ignored.At present,China's power battery research focused mainly on improving its safety performance and working life,etc.while the recycling link is seriously out of line.Related data show that power lithium battery for car power can be used for 3 to 5 years,because the electric vehicle mileage will be significantly reduced,when its capacity is reduced to 80% of the initial capacity or more.But for energy storage systems,these batteries still have a greater use value.Another example,battery of lithium-ion batteries do not contain mercury,cadmium,lead and other toxic heavy metal elements,but their anode and cathode materials,electrolyte solution and other substances have a great impact on the environment.In addition,some research institutions predict that by 2017 lithium will be in short supply with the electric vehicle demand rising.Therefore,research should be carried out on battery recycling and reuse issues earlier.This paper first introduces the development and development trend of electric vehicles from the conceptual aspects,the development ideas and policy support of electric vehicles in China.It explains the first step of the development of power battery technology,the basic power battery sorting method,and some important performance indicators,and then analyzes the attenuation characteristics of the battery performance,and carries out risk assessment and failure analysis on the decommissioned battery.And then emphasizes the importance of life prediction,summed up the current commonly used in some state of charge state(State-Of-Charge,SOC)and life state(State-of-Health,SOH)estimation method,and then based on the remaining life(Remaining useful life,RUL)prediction of the way,from the principle of design can be uploaded,remote access to data decommissioned battery management system.Finally,for the imbalance problem of battery SOC in the cascade energy storage system with independent battery two kinds of cascade methods are proposed,which can realize differentiated charge and discharge.And the method that is based on the characteristic harmonic to eliminate PWM is in deep argument.When the battery SOC is detected to be unbalanced,the battery SOC is made to be consistent by the differentiated charge and discharge control.When the battery SOC reaches the equilibrium,the phase shift SPWM control is switched to the synchronous charge and discharge.This method improves the availability of the combined cascade energy storage system and the effective capacity of the energy storage system and improves the power quality of the energy storage system.In this paper,the principle of differentiated charge and discharge control method is deduced,and the switching condition is given.In the PSCAD/EMTDC,a combined cascade energy storage system model is established to verify the effectiveness of the proposed self-balanced control strategy.