高升压比开关耦合电感准Z源逆变器研究

发布时间：2018-05-17 06:42

本文选题：准Z源逆变器 + 开关耦合电感　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：PWM逆变器为新能源发电系统以及交流电机驱动系统中的重要组成部分。针对传统PWM逆变器只能实现降压逆变等固有的缺点,通过在PWM逆变器直流侧增加准Z源网络,构成了准Z源逆变器。准Z源逆变器不仅具有传统PWM逆变器的所有功能,而且能够实现升压逆变,使PWM逆变器的应用范围大大拓展。而升压比是衡量准Z源逆变器升压能力的关键参数,因此研究并改进准Z源逆变器,提高它的升压能力十分有意义。本课题将逆变器等效为交流侧传统PWM逆变器和直流侧准Z源升压网络两部分,分别对前后两级进行数学模型的建立。采用信号流图的建模方法重点研究了直流侧准Z源网络数学模型,得到了系统的交流小信号模型。在此基础上,通过比较不同的直通零矢量调制方法,选择最大增益SVPWM调制法,并对调制过程引入的三次谐波进行分析与消除,确定了调制方案。在提高升压能力方面,采用高升压比开关耦合电感结构对带有开关电感结构的准Z源逆变器进一步改进。在不增加磁性元件数量的前提下,通过耦合电感的变比,使逆变器的升压比明显提高。开关耦合电感结构的工作原理和过程在论文中得到了详细的研究,并与传统准Z源逆变器进行了比较。同时详细给出了具有指导性意义的耦合电感设计过程,进行了仿真研究,验证了改进方案的正确性。在控制系统方面,本课题以逆变器的小信号模型为基础,给出了主电路参数设计方法,并采取电流电压双闭环的控制策略,分析了双闭环PI调节器的参数设计方法,仿真结果也对开关耦合电感准Z源逆变器的稳定性和动态性能进行了验证。
[Abstract]:PWM inverter is an important part of new energy generation system and AC motor drive system. Aiming at the inherent shortcoming that traditional PWM inverter can only realize step-down inverter, a quasi-Z-source inverter is constructed by adding quasi-Z-source network to the DC side of PWM inverter. The quasi-Z-source inverter not only has all the functions of the traditional PWM inverter, but also can realize the boost inverter, which greatly expands the application range of the PWM inverter. The boost ratio is the key parameter to measure the boost capacity of the quasi-Z-source inverter, so it is very meaningful to study and improve the quasi-Z-source inverter. The inverter is equivalent to conventional AC side PWM inverter and DC side quasi Z source boost network in this paper. The mathematical model of DC side quasi Z source network is studied by using the modeling method of signal flow graph, and the AC small signal model of the system is obtained. On this basis, by comparing different direct-pass zero vector modulation methods, the maximum gain SVPWM modulation method is selected, and the third harmonic wave introduced in the modulation process is analyzed and eliminated, and the modulation scheme is determined. In order to improve the boost capacity, the quasi-Z-source inverter with switching inductance structure with high booster ratio is further improved. Without increasing the number of magnetic elements, the boost ratio of the inverter is obviously improved by changing the ratio of coupling inductors. The principle and process of switching coupling inductor structure are studied in detail in this paper, and compared with the traditional quasi-Z source inverter. At the same time, the design process of instructive coupling inductor is given in detail, and the simulation research is carried out to verify the correctness of the improved scheme. In the aspect of control system, based on the small signal model of inverter, the main circuit parameter design method is given, and the control strategy of current and voltage double closed loop is adopted, and the parameter design method of double closed loop Pi regulator is analyzed. The simulation results also verify the stability and dynamic performance of switching coupling inductor quasi Z source inverter.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM464

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