【作者】 陈诚；

【导师】 黄学良； 谭林林； 袁晓冬；

【作者基本信息】 东南大学 ， 电气工程（专业学位）， 2024， 硕士

【摘要】 电动汽车作为取代燃油汽车,推动新能源产业发展的重要工具,已受到社会广泛关注。如何便捷、高效、快速地实现电动汽车电能补充,成为当下新能源汽车发展的重要问题。目前电动汽车有线充电技术存在充电接口插拔易产生接触火花、雨天危险性高等问题,因此,无线充电技术具备出色的便捷性、稳定性与安全性,能较好的满足电动汽车充能的现实需求,在电动汽车领域具备很大的应用潜力。目前,电动汽车无线充电技术的发展仍然存在不足:系统难以满足不同场景负载宽范围功率传输的需求。车端装置的系统参数受相应电动汽车硬件的制约,不宜进行参数调整。因此提升电动汽车无线充电系统的功率兼容性,关键在于地端装置的设计。综上所述,通过研究地端系统的电路拓扑与控制方式,实现宽功率范围无线充电的稳定、高效工作具有重要的应用价值。本文围绕电动汽车无线充电系统地端装置模块自适应控制展开了相关研究,从地端系统硬件架构和控制策略出发,以宽功率范围和高效率能量传输为目标,分别针对无电流过零畸变大功率图腾柱PFC变换器实现方法、逆变器自适应投切及环流抑制等关键方面进行了研究,主要开展了以下工作:1)针对现有电动汽车无线充电系统难以实现宽范围功率兼容的问题,本文采用了一种适用于地端装置宽范围功率调整的功率模块串并联组合方案,通过调整功率模块投切数量实现多等级功率传输。对电动汽车无线充电地端装置各模块进行建模,分析了各模块电路特性。针对不同功率模块连接方式,研究功率模块投切对补偿网络谐振特性的影响,设计了一种谐振电感参数补偿电路。2)针对图腾柱PFC输入电流过零畸变的问题,分析了传统控制策略下开关管驱动信号占空比变化规律,详细探究了电流过零点时电流内环PI失效的原因,总结了造成输入电流过零畸变问题的原因。接着,提出了一种电容注入式改进控制策略,通过改进工作模态,避免电流过零点处开关管占空比突变的情况,实现了图腾柱PFC输入电流在过零点处的平滑过渡,并进行仿真和实验验证。3)针对系统逆变器投切致使电路失谐的问题,分析了逆变器数量和补偿网络参数之间的耦合关系,提出了一种谐振电感参数补偿方法,通过修正谐振电感参数,使得系统具备逆变器数量和补偿网络参数解耦的特性。建立逆变器投切瞬态等效全响应电路模型,分析投切瞬间逆变器输出电流与功率的振荡机理,提出了一种基于暂态分量消除的投切策略,通过选取投切点实现电参量振荡削减,并搭建仿真模型,对所提出的平滑投切策略进行了验证。4)针对逆变器并联状态,各逆变器输出特性不一致产生环流现象,造成系统传输效率降低的问题,建立了两逆变器并联无线充电系统等效电路模型,分别对导致环流的逆变器直流输入电压和谐振电感参数偏差进行定量分析。在此基础上,提出了基于相量同步的环流抑制方法,通过仿真对提出的环流抑制策略进行了验证。5)对电动汽车无线充电系统装置样机硬件电路进行了设计与制作,搭建了两逆变器并联电动汽车无线充电样机实验平台,通过实验验证了环流抑制理论分析与仿真结果。更多还原

【Abstract】 Electric vehicles,as a pivotal tool for replacing fuel-powered vehicles and propelling the advancement of the new energy industry,have garnered extensive societal attention.The efficient,rapid,and convenient replenishment of electric power for these vehicles poses a significant challenge in the evolution of new energy transportation.Currently,wired charging technologies encounter issues such as contact sparks during plug engagement and heightened risks in rainy conditions.Therefore,wireless charging technology emerges as an ideal solution due to its exceptional convenience,stability,and safety features that better cater to the practical requirements of electric vehicle energy replenishment while holding substantial potential for application in this domain.However,the development of wireless charging technology for electric vehicles still faces certain limitations:it struggles to meet demands for power transmission across various operational scenarios.The system parameters of vehicle-side devices are constrained by corresponding electric vehicle hardware;hence adjusting these parameters is inappropriate.Consequently,enhancing power compatibility within the wireless charging system critically relies on designing ground-side devices.Accordingly,conducting research on circuit topology and control methods of ground-side systems to achieve stable and efficient operation throughout a wide power range holds significant practical value.This thesis focuses on the adaptive control of the ground-side device module in wireless charging systems for electric vehicles.Starting with an analysis of the hardware architecture and control strategy of the ground-side system,this study investigates key technologies such as implementation methods for a high-power totem-pole power factor correction(PFC)converter with significant reduction in zero-current distortion,adaptive switching techniques for inverters,and suppression of circulating currents.The primary contributions of this research are as follows:1)Addressing the issue of achieving wide-range power compatibility in existing electric vehicle wireless charging systems,this thesis employs a power module combination scheme of series and parallel connections suitable for wide-range power adjustment in ground-side devices.By adjusting the number of power modules switched on,multi-level power transmission is achieved.The modules of the electric vehicle wireless charging ground-side device are modeled,and the circuit characteristics of each module are analyzed.The impact of power module switching on the resonance characteristics of the compensation network is studied,and a novel ground-side transmitter based on resonant inductor compensation is proposed.2)Concerning the problem of zero-cross distortion of the totem pole PFC input current,the variation of the switch driver signal duty cycle under traditional control strategies is analyzed.The reasons for the ineffectiveness of the current inner-loop PI at the zero-crossing point are thoroughly investigated,summarizing the causes of input current zero-cross distortion.Subsequently,an improved control strategy using capacitor injection is proposed.By modifying the operational mode,sudden changes in the duty cycle of the switching tube at the zero-crossing point are avoided,achieving a smooth transition of the totem pole PFC input current at the zero-crossing point,with simulation and experimental validation provided.3)Addressing the issue of circuit detuning caused by inverter switching,the coupling between the number of inverters and the parameters of the compensation network is analyzed.A resonant inductor parameter compensation method is proposed,by adjusting the resonant inductor parameters,decoupling the number of inverters from the network parameters is achieved.A transient full-response circuit model for system inverter switching is established,analyzing the oscillation mechanism of inverter output current and power during switching.A smooth switching strategy based on transient component elimination is proposed,selecting switching points to reduce oscillations in electrical parameters,with a simulation model constructed and the smooth switching strategy validated.4)Regarding the phenomenon of circulating currents produced by inconsistent output characteristics of inverters in parallel states,leading to reduced system transmission efficiency,an equivalent circuit model for a two-inverter parallel wireless charging system is established.Quantitative analysis of the causes of circulating currents,such as DC input voltage of inverters and deviations in resonant inductors,is conducted.A phase-synchronization-based circulating current suppression method is proposed,with simulations validating the proposed suppression strategy.5)The hardware circuit of electric vehicle wireless charging system device prototype is designed and manufactured,and the experimental platform of electric vehicle wireless charging prototype with two inverters in parallel is built.The theoretical analysis and simulation results of circulation suppression are verified by experiments.更多还原