Research Of Safety Management Strategy Of Power Battery System Of Electric Passenger Car

The safety of power batteries for electric buses is the biggest challenge of the current high-energy-density battery system to promote the application on electric buses.Safety is a system project,cannot only consider a single perspective,must combine internal and external factors to make comprehensive security management strategy.Select power battery system of pure electric bus and plug-in electric bus as the research object,based on the positive safety and passive safety management strategy research,complete safety management strategy of the power battery for electric bus,operate MIL & HIL tests,and prototype vehicle road tests.Carry out framework design of positive safety and passive safety management: Positive safety management is based on State of Power(SOP)estimation,insulation test,state estimation,limit information protection and charging safety;passive safety management is based on fire extinguishing system and monitoring system for batteries.Through reasonable optimization on positive safety and passive safety management,to achieve safe,efficient and reliable operation of the battery system.Positive safety management strategy for power battery system: Study power system SOP estimation method based on the internal resistance and look-up table method,considering the power system fault information’s influence on the SOP estimation,establish a model of SOP estimation based on the vehicle control strategy;Carry out security management strategy study based on insulation alarm status was carried out,complete algorithm model construction based on Matlab/Simulink;Study and put forward safety management based on the battery charging state of SOC dynamic follow and graded warning mechanism,combine power battery safety standards and policies,improve the positive safety management strategy design on power battery system.Power battery system passive safety management strategy: through the study of combustion mechanism of power lithium ion battery,put forward power battery system design of fire extinguisher,formulate fire extinguishing system alarm mechanism,and take different measures according to different alarm level;According to the characteristics of the battery system on buses,the design of 24-hour monitoring system is carried out in the aspects of electrical system and control strategy.Finally,the effectiveness of the proposed method was verified through the platform and the vehicle test based on the power safety system.