人类社会面临的能源危机和环境污染日趋严重，促使能源系统向清洁低碳的可再生能源方向发展，新能源汽车已经成为人们关注的焦点。质子交换膜燃料电池汽车以氢气为燃料，适用于长距离、大载荷场景，具有很好的应用前景。低温环境适应性是燃料电池汽车商业化道路上面临的重要挑战之一。燃料电池电堆内部状态分布不均匀，零下环境低温启动容易造成内部结冰和电堆损坏。受限于模型精度与计算量的矛盾，缺乏对应大面积多片电堆低温启动内部机理和状态分布的模型，难以实现低温启动过程内部状态分布、温升速率和能效的优化控制。低温环境整车运行能耗高，缺乏高效的氢-电-热耦合系统及控制方法，难以实现整车的能耗和续驶里程的优化。本文进行了燃料电池低温启动建模研究。建立了燃料电池低温启动一维机理模型，揭示了低温启动过程膜电极状态分布机理。针对机理模型精度与计算时间的矛盾，提出了催化剂层分区降维简化方法，建立了降维简化模型，关键位置状态分布和精度与数值模型接近，计算时间减小至数值模型的十分之一。建立了大面积多片电堆伪三维模型，实现电堆低温启动过程动态仿真及内部状态分布描述，为控制方法研究提供了模型基础。本文进行了燃料电池低温启动方法研究。针对低温启动电堆一致性恶化的问题，研究了端板加热优化方法，设计了新型端板加热结构。提出了基于物质再循环的低温启动方法，提高了温升速率并改善内部不均匀性。优化冷却水循环并提出间歇式控制方法，实现了启动到运行的平稳过渡。提出了面向实际系统的分步启动方法，改善了堆内温度一致性，显著提升电堆热量利用率和温升速率。本文进行了低温环境燃料电池客车整车热管理研究。针对低温环境下燃料电池客车能耗高的问题，提出了整车氢-电-热多域耦合热管理方法，设计了基于燃料电池余热供暖的新型整车热管理系统，建立系统模型并设计多模式控制策略和温度控制算法，基于模型仿真进行系统能效分析和优化。本文提出的低温启动方法应用在燃料电池发动机上，成功实现石墨双极板电堆的-30°C低温启动。面向2022年北京-张家口冬奥会应用场景，本文提出的热管理系统和方法在燃料电池公交车和高速公路客车上应用，实车道路示范运营表明，车辆冬季能耗相比传统方案降低1 kg/100 km，节能12%。

Energy crisis and environment pollution faced by human beings acceletrate the transform of energy system to renewable energy and the development of new energy vehilcle. With the strength in long distance and heavy duty application, hydrogen based polymer electrolyte membrane fuel cell vehicle has a good application prospect. However, low temperature environment adaptability ramians one of the main obstacles on the further commercialization of fuel cell vehicles. Starting up from sub-zero temperature environment may cause water freezing in fuel cells and enven damange, and the internal states inside fuel cell stack are unevenly distributed. Restrited to the trade off between model accuracy and computation cost, there is lack of fuel cells cold start model that can describe both mechanism of cold start and internal state distribution. Thus it is difficult to realize optimization of internal state distribution, heating rate and energy utility. Heat supply in low-temperature environment significantly increases the energy consumption of fuel cell vehicle. Efficient hydrogen-electricity-heat coupled system management method is deeded to improve the energy consumption and driving range.Fuel cells cold start modelling is studied in this dissertation. A one-dimenssional model of single cell cold start is developed, describing the internal states distribution and transient process in MEA. In order to overcome the trade off between model accuraty and computation cost, CL-partition method is proposed to develop dimension reduction simplified model, which inherts the key feature of one dimensional model but only costs one tenth of the computation time. Based on the simplified model, cold start model of fuel cell stack is developed. The simulation of cold start process and internal state distribution of fuel cell stack with large area and multi cells provides model basis for cold start method study.Fuel cells cold start strategy is then studied in this dissertation. End plate heating method is optimized and a novel end plate self heating structure is proposed in order to improve the temperature inconsistency in fuel cell stack during cold start. Dual recirculation based cold start strategy is proposed to further improve the heating rate and internal state distribution. Cooling system is optimized and intermittent coolant control strategy is proposed, realizing the smooth transition from cold start to steady operation. For real fuel cell system and different operation temperatures, a multi step cold start strategy is designed. Through energy flow and mass flow optimization, the temperature consistency, temperature rising rate and energy utlity are significantly improved.In order to improve the energy consumption of fuel cell vehicle in low-temperature, thermal management of fuel cell vehicle is studied. A hydrogen-electricity-heat coupled thermal management method is proposed anda a novel thermal management system based on fuel cell wasted heat recovery is designed. System model is developed and a simulation platform is established. Multi mode control strategy and temperature regulation algorithm is then developed. Simulation studies is then conducted to analyze and optimize the proposed system and control strategy. The fuel cells cold start method proposed in this dissertation has been applied on fuel cell engine, realizing successful cold start from -30°C of fuel cell stack with graphite bipolar plates. The proposed themal management system and method has been applied on fuel cell city bus and interurban bus, which will serve in the 2022 Beijing-Zhangjiakou Winter Olympic Games. Real road demonstration shows 1 kg/100km reduction of hydrogen consumption in winter comparing to traditional solution, realizing 12% erergy saving.