电动汽车Li-ion电池与SC混合储能系统能量管理策略研究

Hybrid energy storage system can make up for the inadequacy of using single battery for electric vehicle power supply, but its nonlinear characteristics and the complexity of the multiple energy storage units involved result in their difficulty in charging and discharging control and energy management, which seriously restrict the large-scale promotion of electric vehicles. Therefore, with the actual working condition of electric car, this project aims at analysising the hybrid energy storage system structure of lithium-ion battery and super capacitor, building an efficient topology structure and the equivalent model with higher accuracy; researching and improving the battery pack based on the degradation of capacity attenuation model, combining the theory of probability, put forward an estimation algorithm for high precision online estimates the health status of hybrid energy storage system and charged state; under different EV working conditions, establish a multiple objective function between energy and power demand and solve the function, obtain each storage unit efficiency coefficient for hybrid energy storage system, optimize each unit of power and energy of hybrid energy storage system management method; study frequency pulse fast charge method and equilibrium strategy, further improve the charging efficiency of hybrid energy storage system to prolong the life span. On this basis, design and implement a system with coordinated control in each hybrid energy storage units ,verifing the correctness and effectiveness of the proposed method. This study of this project provide the theory method and technical support,and promote the application of electric vehicle .

混合储能系统能弥补采用单一蓄电池作为电动汽车动力源的不足，但其非线性特性以及多储能单元的结构复杂性导致充放电控制及能量管理困难，严重制约电动汽车大规模推广。为此本项目结合电动汽车实际工况分析锂离子电池和超级电容器混合储能系统结构，构建高效率拓扑结构和高精度的等效模型；研究电池组基于容量衰减的退化模型，结合概率理论，提出高精度在线估算混合储能系统的健康状态和荷电状态的估算算法；建立满足电动汽车不同工况下能量和功率需求的多目标函数并求解，获得混合储能系统各储能单元出力系数，优化混合储能系统各单元功率和能量管理方法；研究变频脉冲快速充电方法及均衡策略，进一步提高混合储能系统充电效率延长其寿命。在此基础上，设计实现混合储能各单元能量和功率协调控制系统，验证所提方法的正确性与有效性。本项目研究可为电动汽车混合储能系统能量控制提供相应理论方法和技术支持，促进电动汽车推广应用。

为解决混合储能系统(Hybrid Energy Storage System, HESS)非线性特性以及多储能单元的结构复杂性导致充放电控制及能量管理困难等问题，本项目在对电动汽车功率需求进行深入分析的基础上，重点对锂离子电池和超级电容器构成的HESS能量管理的理论和方法展开了研究。主要包括HESS等效模型及高效率拓扑结构、HESS中超级电容器和锂离子电池的SOC及SOH估算算法、HESS能量和功率管理方法研究、高效的快速充电方法及均衡控制策略。为验证模型的正确性和算法的有效性，设计了HESS优化能量管理模拟系统，以提高HESS的负载适应能力，优化电动汽车整车动力性能；并建立了能综合反映HESS特性的模型，充分考虑车用锂离子电池和超级电容器的非线性以及实时、在线等因素；同时研究了高精度SOC、SOH估算算法，并根据车辆行驶工况和HESS状态来分配蓄电池和超级电容器的能量流向；对HESS快速高效的变频脉冲充电和无损均衡控制策略进行了仿真实验及硬件实物开发。本研究为HESS能量管理、快速充电技术和电池均衡技术奠定了坚实的工作基础，同时对于HESS的SOC和SOH估算提供了重要的启示性线索，完成了项目任务书的相关要求。