燃料电池混合动力系统的极小值控制策略

质子交换膜燃料电池和蓄电池构成的混合动力系统在UUV上有着广阔的应用前景。由于燃料电池自身的工作效率和循环寿命与其工作状态直接相关,因此协调2个能量单元之间的功率分配就成了混合动力系统在开发过程中的关键任务。为了利用能量分配使整个系统工况达到最优,一系列最优化控制理论在混合动力系统中得到应用,并发挥了重要作用。为了将系统的等效氢气消耗总量降到最低,本文重点介绍一种针对UUV混合动力系统的基于极小值原理的能量管理策略。相比之前的控制策略,本文方法能够将全局优化问题转化为局部优化问题,且无需全航程的功率信息作为先验知识。最后利用某小型UUV的典型功率负载曲线开展模拟计算,计算结果显示,从3种不同的初始值开始计算过程最终都能收敛至最优解的某个邻域内,说明提出的控制算法具有很好的鲁棒性,能够在UUV的能量管理系统中实现很好的在线功率分配,达到等效氢耗量最小的优化目标。本文方法具有计算效率高、占用内存少的优势,为实现工程应用中的在线调节创造了可能。

Pontryagin's minimum principle control strategy for fuel cell hybrid power system

Hybrid power system which consists of a proton exchange membrane fuel cell and a battery has great perspective for Unmanned Underwater Vehicles(UUVs)?As fuel cell's working point has a direct relationship with its efficiency and lifetime,a key concern of the hybrid power system is the power distribution between the two parts.In order to optimize the power distribution,optimal control method is often equipped with the hybrid power system.Aiming at minimizing the equivalent hydrogen cost,this work present an optimal real-time energy management strategy based on the Pontryagin's minimum principle for UUV's hybrid power system.Compared with some other methods,this approach convert the global optimization into a local one and don't need the whole trip profile as a prior knowledge.In this research,a typical UUV working profile is tested with different initial co-state values to evaluate the proposed method,and the results indicate it shows good robustness and effectiveness.In addition,this method possesses shorter calculation time and smaller storing space,which is helpful for online optimization in actual applications.