VIENNA整流器的控制策略研究

发布时间：2018-06-02 09:12

本文选题：VIENNA整流器 + SVPWM控制　；参考：《电子科技大学》2017年硕士论文

【摘要】：由于国家工业的发展迅猛,变流装置得到了广泛的应用,而其带来的一大问题就是电网污染。大量无功功率和谐波注入电网,使得电能质量降低。因此,提高电能质量问题成为当下的一大热点。VIENNA整流器作为一种典型的拓扑结构,一经提出,便受到了广泛的关注。作为一种三电平拓扑结构,开关管电压应力比两电平拓扑低;上下桥臂不会同时导通,不用考虑死区时间,而且开关管的减少使得控制算法易于实现。因此,从经济和安全性方面考虑,对VIENNA整流器控制技术的研究具有很大的实用价值。本文首先介绍了VIENNA整流器的工作原理,分析了各个开关状态下的工作状态,在此基础上对VIENNA整流器进行分析,得到了其在abc自然坐标系以及dq旋转坐标系下的数学模型,为下文的研究打下了基础。其次介绍了空间矢量调制算法,由于传统的SVPWM控制方法需要进行复杂的电流区间判断,因此,通过对电压辅助区间的分析运用简化了调制过程。针对输出端中点电压不平衡的问题,利用小矢量对中点电压的影响,设计了均压模块来调节中点电压的平衡。再次介绍了VIENNA整流器双闭环控制策略,通过分析电压外环在系统启动和负载突变时动态响应差的问题,提出了一种优化的电压外环的控制方法,并进行了仿真验证。通过两种方法下的仿真对比,验证了优化的电压外环控制方法的可行性。最后在Matlab/Simulink平台上搭建了VIENNA整流器的仿真模型,对控制方法进行了验证。搭建了7.5kW电动汽车直流充电模块实验平台,介绍了系统的软件流程,并在硬件平台上对控制算法进行了验证,验证了系统所采用控制策略的有效性。
[Abstract]:Because of the rapid development of national industry, converters have been widely used, and one of its major problems is power grid pollution. A large number of reactive power and harmonics are injected into the power grid, which reduces the power quality. Therefore, the improvement of power quality has become a hot topic. As a typical topology, VIENNA rectifier has been widely concerned. As a three-level topology, the voltage stress of the switch is lower than that of the two-level topology, the upper and lower arms do not switch on at the same time, the dead-time is not considered, and the reduction of the switch makes the control algorithm easy to implement. Therefore, the study of VIENNA rectifier control technology is of great practical value in terms of economy and security. In this paper, the working principle of VIENNA rectifier is introduced, and the working state of each switching state is analyzed. On this basis, the mathematical models of VIENNA rectifier in abc natural coordinate system and dq rotating coordinate system are obtained. It lays a foundation for the following research. Secondly, the space vector modulation algorithm is introduced. Because the traditional SVPWM control method needs to judge the complex current range, the modulation process is simplified by the analysis of the voltage auxiliary region. Aiming at the imbalance of the midpoint voltage at the output end, a voltage balancing module is designed to adjust the voltage balance of the midpoint voltage by using the influence of the small vector on the midpoint voltage. The double closed loop control strategy of VIENNA rectifier is introduced again. By analyzing the dynamic response difference of the voltage outer loop when the system starts and the load changes, an optimized control method of the voltage outer loop is proposed and verified by simulation. The feasibility of the optimized voltage outer loop control method is verified by the simulation and comparison between the two methods. Finally, the simulation model of VIENNA rectifier is built on Matlab/Simulink platform, and the control method is verified. The experiment platform of DC charging module for 7.5kW electric vehicle is built, the software flow of the system is introduced, and the control algorithm is verified on the hardware platform, which verifies the effectiveness of the control strategy adopted by the system.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM461

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