五电平逆变器SVPWM控制策略及过调制研究

发布时间：2018-10-10 14:20

【摘要】：多电平（Multilevel）逆变器广泛应用于大功率交流调速、有源滤波器、船舶推进等中高压、大功率工业场合。与传统变换器相比，多电平变换器具有输出性能好，谐波含量低，开关损耗低，电磁干扰小等优点。本文以二极管箝位型五电平逆变器为研究对象，对多电平中的关键技术进行研究。首先，介绍了NPC/H等多电平逆变器的拓扑结构，重点分析了二极管箝位型五电平逆变器的工作原理。介绍了SVPWM空间矢量调制算法及七段式开关序列的设计，研究了四种简化空间矢量脉宽调制策略：基于m-n坐标系算法、无坐标系算法、基于两电平分解算法以及分类算法，并应用于五电平矢量调制中，调制策略相对传统SVPWM调制方法简化了基本矢量的选取和作用时间的计算，省去了大量三角函数运算，节省了处理器的资源，通过仿真及实验证明了调制策略的正确性和有效性。其次，为了改善逆变器的输出性能、充分利用直流侧电压，获得最大电磁转矩，本文针对五电平逆变器过调制控制策略进行深入研究。分别探讨了基于两电平分解、分类算法及叠加原理的过调制处理方案，，给出了输出基波电压和谐波频谱，说明参考电压矢量能够从线性调制区域向过调制区域平滑过渡，扩大逆变器的运行范围。仿真和实验验证了过调制策略的有效性和准确性。再次，分析研究了五电平矢量控制系统，以永磁同步电机作为五电平逆变器负载。分析了永磁同步电机的数学模型，讨论了转子磁链定向的id=0控制。仿真及实验表明id=0控制方式下的五电平矢量控制系统具有良好的动、静态性能，电机的转速和位置可以实现快速跟踪，而且误差很小，实现了电机的最大转矩控制。最后，本文完成了NPC五电平逆变器主电路及控制系统的软、硬件设计，以TMS320F28335DSP和XC3S400FPGA为核心的控制系统搭建了NPC五电平逆变器实验平台，并基于该实验平台完成了本文所采用控制策略的相关实验的研究。
[Abstract]:Multilevel (Multilevel) inverter is widely used in high power AC speed regulation, active filter, ship propulsion and other high voltage, high power industrial occasions. Compared with conventional converters, multilevel converters have the advantages of better output performance, lower harmonic content, lower switching loss and less electromagnetic interference. In this paper, the key techniques of multilevel inverter are studied based on diode-clamped five-level inverter. Firstly, the topology of multilevel inverter such as NPC/H is introduced, and the working principle of diode clamped five-level inverter is analyzed. This paper introduces the design of SVPWM space vector modulation algorithm and seven-segment switch sequence, and studies four simplified space vector pulse width modulation strategies: based on m-n coordinate system algorithm, non-coordinate system algorithm, two-level decomposition algorithm and classification algorithm. Compared with the traditional SVPWM modulation method, the modulation strategy simplifies the selection of the basic vector and the calculation of the working time, saves a large number of trigonometric function operations, and saves the processor resources. The correctness and effectiveness of the modulation strategy are proved by simulation and experiment. Secondly, in order to improve the output performance of the inverter and make full use of the DC side voltage to obtain the maximum electromagnetic torque, the overmodulation control strategy of the five-level inverter is studied in this paper. The over-modulation processing scheme based on two-level decomposition, classification algorithm and superposition principle is discussed, and the output fundamental voltage and harmonic spectrum are given. It is shown that the reference voltage vector can smooth transition from linear modulation region to over-modulation region. Expand the scope of operation of the inverter. Simulations and experiments verify the effectiveness and accuracy of the overmodulation strategy. Thirdly, the five-level vector control system is analyzed and studied. The permanent magnet synchronous motor (PMSM) is used as the load of the five-level inverter. The mathematical model of permanent magnet synchronous motor (PMSM) is analyzed, and the id=0 control of rotor flux orientation is discussed. Simulation and experiments show that the five-level vector control system based on id=0 has good dynamic and static performance, the speed and position of the motor can be tracked quickly, and the error is very small, and the maximum torque control of the motor is realized. Finally, the software and hardware design of the main circuit and control system of NPC five-level inverter is completed. The experimental platform of NPC five-level inverter is built with TMS320F28335DSP and XC3S400FPGA as the core control system. Based on the experimental platform, the related experiments of the control strategy adopted in this paper are completed.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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