【作者】 李晶；

【导师】 姜久春；

【作者基本信息】 北京交通大学 ， 电力电子与电力传动， 2014， 博士

【摘要】 纯电动汽车充电系统的稳定性与谐波特性随使用环境的改变而发生变化,本文以三相PWM整流器模块与DC-DC变换器模块组成的充电系统为研究对象,分析电网分布参数、动力电池特性、充电模块数量的变化对系统的稳定性、瞬态响应、谐波特性的影响,以便为纯电动汽车充电系统的设计提供理论和实践的支持。首先,建立了理想工作环境中的三相PWM整流器在dq坐标系中的降阶线性小信号二端口模型与DC-DC变换器在恒压充电模式与恒流充电模式中的线性小信号二端口模型。理想工作环境中充电机数学模型的建立为充电机在非理想工作环境中的稳定性、瞬态响应与谐波特性分析奠定了数学基础。在考虑输入电源与输出负载特性的情况下,建立了三相PWM整流器与DC-DC变换器的数学模型,找出了影响数学模型稳定性的关键因子。针对关键因子分析在理想使用环境下设计的充电机在非理想输入电源与非理想输出负载的情况下的稳定性与瞬态响应如何改变。研究表明：电源的输出阻抗与负载的输入阻抗共同作用影响充电系统的稳定性与瞬态响应,不同的负载类型对系统稳定性的影响程度不同,针对理想使用环境设计的充电机要留有足够的稳定裕量才能够在使用环境变化时仍然稳定。在充电系统的两种基本结构,即共交流母线结构与共直流母线结构中,建立了三相PWM整流器与DC-DC变换器的数学模型,找出了影响系统稳定性的关键因子。针对关键因子分析充电机组成充电系统后的稳定性与瞬态响应如何改变。研究表明：在交流母线或直流母线容量足够大时,母线上可以同时稳定运行的充电模块数量仍然是有限的,该数量可以使用母线输出阻抗与充电模块输入阻抗比值的根轨迹在虚轴上分岔点处的增益来估计。建立三相PWM整流器在dq坐标系中的Norton模型,将电网谐波电压与基波电压一同转换到dq坐标系中,分析电网输出阻抗与PWM整流器输入阻抗相互作用对电网中谐波电压引起的谐波电流的放大作用。研究表明：电网输出阻抗与三相PWM整流器的输入阻抗相互作用会放大电网中某些频率的谐波电压成分所产生的谐波电流。更多还原

【Abstract】 In the pure electric vehicle charging system which composed of three-phase PWM rectifier modules and DC-DC converter modules, studies have been made on the stability, the transient response and the harmonic changing with operating environment variation.Three-phase PWM rectifier reduction linear small signal model in the dq coordinates, the constant-voltage mode DC-DC converters linear small signal model and constant-current mode DC-DC converters linear small signal model are built.Considering the operating environment of the charging system, find the key factors which influence the charger mathematical model. Simulation and experimental results show that power output impedance and load input impedance together affect the charging system stability and transient response, the design of the charging system must allow sufficient stability margin to be able to remain stable when operating environment changed.Considering two basic architecture of the charging system, AC bus architecture and DC bus architecture, find the key factors that affect system stability and transient response. Simulation and experimental results show that the charging system’s environment will affect the charging system stability, transient response. If the quantity of charging molues are not limited, the stability of the charging system can be changed. The maximum quantity of charging modules of the bus can be estimated by the root locus of the ratio of bus output impedance and charging module input impedance.Three-phase PWM rectifier Norton model is established in the dq coordinates, harmonic voltage together with the fundamental voltage were converted to the dq coordinates, then analyze harmonic currents changes which caused by grid output impedance interaction with PWM rectifier input impedance. Simulation and experimental results show that the charging system’s environment will affect the charging system harmonic. Grid output impedance and the input impedance of the three-phase PWM rectifier interaction will enlarge the grid current harmonics component of certain frequency.更多还原