超级电容具有功率密度大的特点,将其作为电动车的辅助电源,能够弥补动力电池功率密度低的缺陷。以电动车再生制动系统为研究对象,建立由直流无刷电动机和Buck—Boost型DC-DC变换器、超级电容组及控制器组成的复合电源的电动车再生制动系统的数学模型。为对电动车再生制动系统模型进行验证,设计开发再生制动模拟试验系统,采用小功率直流无刷轮毂电动机驱动系统模拟电动车驱动系统,采用飞轮惯性矩模拟电动车惯性负载。在此基础上对再生制动系统数学模型进行仿真计算和试验验证,结果表明所建立的数学模型准确有效。以制动过程中制动力矩波动范围小为目标,采用恒流控制策略对电枢电流进行控制。仿真结果表明,由动力电池和超级电容组成的电动车复合电源,能够有效吸收再生制动能量,所采用的恒流控制策略能够实现制动过程中的制动力矩稳定及较高的能量回收效率。
Due to the characteristics of high power density existing in super capacitor, the defects of low power density in power battery can be remedied, by using super capacitor as the auxiliary power source of electric vehicle, electric vehicle regenerative braking system is acted as the research object, the mathematical models of electric vehicle regenerative braking system of composite power sources are established, consisting of the brushless dc motor, Buck-Boost DC-DC converter, super capacitor as well as controller. In order to validate the electric vehicle regenerative braking system model, the regenerative braking simulation test system is designed and developed, the small power brushless dc wheel motor drive system is used to simulate electric vehicle drive system, the flywheel moment of inertia is used to simulate electric vehicle inertia load. The mathematical models of regenerative braking system are calculated and experimental verified, the results show that the mathematical model established is accurate and effective. In order to maintain small braking torque fluctuation range during the braking process, constant current control strategy is employed to control the armature current. As simulation results and experiment data shows, electric vehicle composite power source, consisting of power battery and super capacitor, can effectively absorb the regenerative braking energy. By adopting the constant current control strategies, stable braking torque can be implemented in the process of braking, and higher enerL-~ recovery efficiencv is realized.