五电平变换器电流无差拍控制技术研究

发布时间：2018-02-28 20:44

本文关键词： 五电平逆变器 SVPWM g-h坐标系 PI控制无差拍控制　出处：《中国矿业大学》2014年硕士论文　论文类型：学位论文

【摘要】：多电平逆变器（Multilevel Inverter）在大功率交流调速、有源滤波器、交流柔性输电等中高压、大容量工业应用领域得到广泛应用，其主要原因是：与传统两电平逆变器相比，多电平逆变器具有输出性能好、谐波含量低、开关损耗小、电磁干扰小等优点。本文以二极管箝位式（NPC）五电平逆变器矢量控制系统为研究对象，对其SVPWM算法、电流控制策略等环节进行了研究，，主要研究内容如下：首先，对NPC五电平逆变器工作原理进行了分析。介绍了SVPWM空间矢量调制算法的原理，以两电平为例分析了传统SVPWM算法的实现步骤，在此基础上，研究了一种基于g-h坐标系的五电平电压空间矢量脉宽调制策略，相对传统SVPWM调制策略，该调制策略使基矢量选取和作用时间计算得到简化，算法实现过程中省去了大量三角函数运算，节省了算法运行时间。仿真和实验结果验证了算法的可行性。其次，分析了五电平逆变器永磁同步电机（PMSM）矢量控制系统中的电流控制策略。本文主要针对电流PI控制和电流无差拍控制两种算法进行了分析，分别对其算法原理、参数设计和控制性能进行了研究，理论推导和仿真结果表明，电流PI控制算法带宽受限制并且在稳态精度和快速性上存在矛盾；无差拍控制算法响应快、能实现无差跟踪，但它是基于控制对象精确数学模型的算法，对系统参数依赖性大，鲁棒性不高。本文采用改进无差拍控制算法，提高了系统的鲁棒性，同时该算法对降低电机转矩脉动具有优良的特性。在电流控制策略理论分析的基础上，对电流PI控制和电流改进无差拍控制进行了MATLAB仿真。搭建了五电平矢量控制系统仿真模型，五电平逆变器以PMSM为负载，对电流PI控制策略和电流改进无差拍控制策略进行了仿真研究。仿真结果表明，相对电流PI控制策略，改进无差拍控制策略在保证较快的响应速度条件下，电机的转矩脉动更小，能实现无差跟踪。最后，搭建了五电平逆变器实验平台，设计了基于TMS320F28335DSP和XC3S400FPGA为核心的控制系统，给出了实验平台各模块参数设计，并基于该实验平台完成了电流PI控制和改进电流无差拍控制两种算法的实验，实验结果与仿真结果一致，为将无差拍控制策略应用于五电平逆变器并将其实用化提供了理论依据。
[Abstract]:The multi - level inverter is widely used in high - voltage and large - capacity industrial application fields such as high - power AC speed regulation , active filter , AC flexible transmission , etc . The main reason is that the multilevel inverter has the advantages of good output performance , low harmonic content , low switching loss and small electromagnetic interference compared with the traditional two - level inverter . First , the working principle of NPC five - level inverter is analyzed . The principle of the space vector modulation algorithm is introduced . Based on this , a five - level voltage space vector pulse width modulation ( PWM ) strategy based on the g - h coordinate system is analyzed . Based on this , a five - level voltage space vector pulse width modulation ( PWM ) strategy based on g - h coordinate system is presented . Secondly , the current control strategy in a five - level inverter permanent magnet synchronous motor ( PMSM ) vector control system is analyzed . The principle , parameter design and control performance of the current PI control algorithm are studied . The results show that the bandwidth of the current PI control algorithm is limited and there is a contradiction in the steady state accuracy and speediness . On the basis of current control strategy theory , MATLAB simulation is carried out on current PI control and current improving non - beat control . A five - level vector control system simulation model is built , and five - level inverter is used as a load to simulate current PI control strategy and current improved non - difference beat control strategy . Finally , a five - level inverter experiment platform is built , and the control system based on the DSP and XC3S400FPGA is designed . The experimental results are consistent with the simulation results . The experimental results are consistent with the simulation results . In order to apply the sensorless control strategy to the five - level inverter and provide the theoretical basis for practical application .

【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】：TM46

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