基于多绕组中频变压器的新型车载变换器拓扑结构及控制策略研究

To overcome the drawbacks of traditional electric vehicle (EV) converter, such as low power density and low reliability, this project proposed a novel EV converter topology by combining multiphase electric machine, multilevel converter and medium frequency multi-winding transformer. The proposed EV converter consists of electric machine converter, energy storage converter and medium frequency multi-winding transformer, with no common DC bus with large amount of capacitors in electric machine converter or no large amount of battery cells in series in energy storage converter. It possesses the advantage of compact structure, high power density, improved operating and harmonic characteristics and high reliability and so on. It is a widely available EV converter topology, which can use both AC and DC input, can work in different modes such as pure electric mode and hybrid electric mode, and can support both of battery charging and battery replacement. This project focused on the study of modulation method, control method of electric machine converter, control method of energy storage converter and energy management strategy. The ultimate goal is to provide a complete solution of EV converter system with high power density, high reliability, high control performance and high performance-price ratio and lay a solid foundation for the future application in industry.

为了解决传统电动汽车变换器功率密度低、可靠性差等问题，本课题将多相电机、多电平变换器和多绕组中频变压器相结合，提出了一种新型车载变换器拓扑，该拓扑由电机控制变换器、储能变换器和将它们以磁通方式耦合在一起的多绕组中频变压器组成，其电机变换器侧无大容量公共直流母线，储能变换器侧无大量储能单体串联，整个拓扑具有结构紧凑、功率密度高、运行性能和谐波特性好、故障冗余运行能力强等特点。该拓扑输入侧兼容交直流两种输入，运行模式上兼容纯电动、混合动力等多种模式，充电方式上兼容换电、插电两种方式，是一种具有广泛适用性的车载变换器解决方案。课题对该拓扑的调制策略、电机控制系统控制方法、储能系统控制方法和能量管理策略等进行了深入研究，最终目标是实现一整套功率密度高、可靠性好、具有良好控制性能和性价比的车载变换器系统，为其在实际中的推广应用奠定技术基础。

为了解决传统电动汽车变换器功率密度低、可靠性差等问题，本课题将多相电机、多电平变换器和多绕组中频变压器相结合，提出了一种新型车载变换器拓扑，该拓扑由电机控制变换器、储能变换器和将它们以磁通方式耦合在一起的多绕组中频变压器组成，其电机变换器侧无大容量公共直流母线，储能变换器侧无大量储能单体串联，整个拓扑具有结构紧凑、功率密度高、运行性能和谐波特性好、故障冗余运行能力强等特点。该拓扑输入侧兼容交直流两种输入，运行模式上兼容纯电动、混合动力等多种模式，充电方式上兼容换电、插电两种方式，是一种具有广泛适用性的车载变换器解决方案。课题对该拓扑的调制策略、电机控制系统控制方法、储能系统控制方法和能量管理策略等进行了深入研究，最终目标是实现一整套功率密度高、可靠性好、具有良好控制性能和性价比的车载变换器系统，为其在实际中的推广应用奠定技术基础。