电动汽车用高性能双向充电拓扑构造及非线性控制策略研究

In order to address the environmental and energy issues, developing the new energy vehicles (EVs) has been listed in the emerging sectors of strategic importance in China. However, as a fundamental power supply facility for EVs, the DC charger has such problems as single direction power flow, poor gird-connection stability, weak load adaptability and so on. These issues directly restrict the development and applications of EVs. Thus, this project aims to research the high-quality bidirectional charger for EVs. Based on the silicon carbide devices, using the methods of functional unit re-combination and auxiliary unit implementation, the project studies the construction principle of bidirectional charger typologies, as well as optimizing the system parameters with the Pareto algorithm. Then, the project develops the generalized state-space model of the gird-side converter (GSC) and the extended describing function model of the battery-side converter (BSC). Subsequently, combing the system operation mechanisms, the project proposes the control strategies for the GSC and the BSC respectively, which are the robustness grid-connected control method combined on back-stepping control and virtual inertia control, and the output adaptive control method based on the impedance model. Finally, a hardware-in-loop simulation and an experimental prototype are designed, in order to verify the correctness of the new topology and its control strategies. The research achievements will provide design guides for topology design, modeling, control strategy and experimental verification of the bidirectional charger system, which are of great significance for the low-cost, high-efficiency, safe and stable operation of the DC charger system.

发展新能源汽车是解决环境和能源问题的关键途径，我国已将其列为重大国家战略新兴产业。然而，作为新能源汽车的基本动力供给设施，直流充电桩存在能量单向流动、并网稳定性差、负载适应能力弱等问题，直接制约新能源汽车规模发展和应用。为此，本项目重点研究电动汽车用高性能双向充电系统，以碳化硅功率器件为基础，以功能单元重组、辅助单元互补为手段，探索双向充电拓扑构造原则，基于Pareto算法优化系统参数设计；建立拓扑的网侧广义状态空间模型和输出侧扩展描述函数模型，结合拓扑运行机理分别设计网侧和输出侧控制策略，即：基于反步控制和虚拟惯量的复合鲁棒并网控制策略和基于阻抗模型的输出自适应控制策略，并分析系统稳定性。最后，研制半实物仿真平台和小功率实验平台，验证新拓扑方案的可行性。研究成果为双向充电系统的拓扑结构+控制策略+实验验证一体化设计提供思路，对充电系统低成本、高效、安全稳定运行等具有重要意义。

本项目围绕电动汽车充电，从拓扑结构、数学建模、非线性控制策略等方面开展研究。在拓扑结构方面，充分探讨了充电系统变流器常见拓扑结构（如三相PWM变流器、矩阵整流器等），并构建了基于SiC功率器件的高频链矩阵变流器充电系统。在数学建模方面，提出一种变流器环路增益精确建模方法，描述了全频域特性及测量的环路增益与注入点位置的定量关系。在非线性控制策略方面，提出了基于干扰观测器的变流器有限时间控制策略，提高了系统直流侧动态响应速度和抗干扰能力；针对不平衡电网工况，提出了变流器的有限时间命令滤波控制策略，在三种不同控制模式下实现了时变功率精准跟踪和直流电压稳定；提出了高频链矩阵变流器的双闭环反步控制策略，实现了动力电池的交流充电和直流充电两种模式，提高了系统鲁棒性；提出了三次谐波注入式矩阵变换器的模型预测控制，消除了常规方案参数调节难的问题，优化了系统输入输出性能。共发表国际权威学术期刊IEEE汇刊论文5篇（SCI 1区），会议论文2篇。授权中国发明专利2件，申请中国发明专利3件。