高效双向电动汽车充电机的研究

发布时间：2018-02-03 14:42

本文关键词： 充电机 PWM变换器 DC/DC 功率前馈无差拍多阶段恒流　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：电动汽车作为一种高效、节能、零排放的交通工具，将成为未来城市的主导。而对电动汽车充电机的研究，将直接影响未来电动汽车的发展。电动汽车充电系统为动力蓄电池提供能量补给，是电动汽车产业的重要支撑系统，也是电动汽车商业化过程中的一个重要环节。由于充电设施中的非线性、冲击性以及不对称负荷所产生的谐波引起电能质量指标恶化，干扰了电力设备及电气负载的正常运行，所以本文研究了一种双向、高功率因数、低谐波的电动汽车充电机。本文主要从以下几个方面进行研究：（1）首先分析了传统电动汽车充电机的拓扑结构和工作原理。传统电动汽车充电机一般采用两级式结构，即前级不可控整流电路和后级DC/DC变换器电路。由于这种充电机存在功率因数低、谐波含量高等问题，所以本文提出了一种高效双向的电动汽车充电机拓扑结构，即前级采用三相PWM变换器电路与后级采用带隔离半桥推挽DC/DC变换器电路，对其工作原理进行了详细分析。（2）通过分析电动汽车蓄电池充电特性，在常规充电和快速充电方式的基础上提出了一种多阶段恒流充电方式。针对双向电动汽车充电机的前级三相PWM变换器提出了一种功率前馈电流无差拍控制策略，实现了系统快速、无差跟踪；针对后级DC/DC变换器提出了一种电压电流双闭环控制策略，，实现了系统的高效充放电。通过仿真验证了所提控制方法的正确性和有效性。文中还对所提控制策略进行了稳定性分析，结果表明控制策略具有良好的稳定性。（3）简单介绍了数字信号处理DSP工作原理与特点，并对事件管理器中的通用定时器、PWM信号产生与捕获单元进行了详细说明。对电动汽车充电机的控制子系统进行了详细阐述，其中包括过零中断模块、采样与数据处理模块、有功分量计算模块、前级功率前馈电流无差拍控制模块、后级电压电流双闭环控制模块。为保证整个系统安全、可靠运行，采用了软件保护子系统。（4）为验证本文所提出拓扑结构的实用性，研制了一台额定功率为20kW的高效双向电动汽车充电机，并详细说明了装置的主电路和控制电路设计方案。实验结果表明本文研究的高效双向电动汽车充电机拓扑结构和控制方法的正确性。本文研究的高效双向电动汽车充电机，为实现零污染、低噪声的电动汽车提供了可能，为实现电网调节用电峰谷差提供了可能。
[Abstract]:As an efficient, energy-saving, zero emission vehicle, electric vehicle will become the dominant city in the future. It will directly affect the development of electric vehicle in the future. The charging system of electric vehicle provides energy supply for the power battery, which is an important supporting system of electric vehicle industry. It is also an important link in the process of commercialization of electric vehicles. Because of the nonlinearity, impact and harmonic produced by asymmetric load in charging facilities, the power quality index is deteriorated. It interferes with the normal operation of power equipment and electrical load, so this paper studies a bidirectional, high power factor, low harmonic electric vehicle charger. Firstly, the topology and working principle of the traditional electric vehicle charger are analyzed. The traditional electric vehicle charger generally adopts the two-stage structure. The former stage uncontrollable rectifier circuit and the rear stage DC/DC converter circuit, because of the low power factor, high harmonic content and other problems. In this paper, an efficient bi-directional electric vehicle charger topology is proposed, that is, the front stage uses three-phase PWM converter circuit and the rear stage uses half bridge push-pull DC/DC converter circuit with isolation. The working principle is analyzed in detail. By analyzing the charging characteristics of electric vehicle battery. On the basis of conventional charging and fast charging, a multi-stage constant current charging method is proposed, and a power feedforward current no-beat control strategy is proposed for the front-stage three-phase PWM converter of bidirectional electric vehicle charger. Slightly. The system is fast and has no difference tracking. A voltage and current double closed loop control strategy is proposed for the rear stage DC/DC converter. The high efficiency charge and discharge of the system is realized. The correctness and effectiveness of the proposed control method are verified by simulation. The stability of the proposed control strategy is also analyzed in this paper. The results show that the control strategy has good stability. This paper briefly introduces the working principle and characteristics of digital signal processing (DSP), and gives a general timer in event manager. The PWM signal generation and acquisition unit is described in detail. The control subsystem of electric vehicle charger is described in detail, including zero-crossing interrupt module, sampling and data processing module. In order to ensure the safe and reliable operation of the whole system, the active power component calculation module, the forward power feedforward current non-beat control module and the rear stage voltage and current double closed loop control module are adopted. In order to verify the practicability of the topology proposed in this paper, a high efficiency bidirectional electric vehicle charger with rated power of 20kW has been developed. The main circuit and control circuit design scheme of the device are described in detail. The experimental results show that the topology structure and control method of the high efficiency bidirectional electric vehicle charger studied in this paper are correct. The high efficiency bidirectional electric vehicle charger studied in this paper provides the possibility for realizing zero pollution and low noise electric vehicle, and it is possible for the power grid to adjust the peak and valley difference of power consumption.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U469.72;TM910.6

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