AC-DC矩阵变换器调制与控制策略的研究

发布时间：2018-01-06 19:21

本文关键词：AC-DC矩阵变换器调制与控制策略的研究　出处：《山东大学》2014年博士论文　论文类型：学位论文

【摘要】：AC-DC矩阵变换器是一种拓扑结构新颖的降压型通用整流装置,由于无需大容量储能元件,所以具有结构紧凑、能量密度高、可靠性和可维护性好的优点,非常适合对重量、体积、效率和可靠性要求较高的应用场合。同时,其正弦输入电流的功率因数可以自由调节,最高可达1,具有天然的能量回馈能力,可以输出双极性电压并导通双向电流,允许负载四象限运行,符合理想整流器的基本要求。本文将理论分析、计算机仿真和样机实验相结合,系统、深入地研究了AC-DC矩阵变换器的空间矢量调制策略、新型非线性控制策略和谐振抑制方法等关键技术问题,为AC-DC矩阵变换器的实用化提供了理论支持和技术准备。本文首先从AC-DC矩阵变换器的空间矢量调制策略出发,深入分析了AC-DC矩阵变换器的变换关系。为了抑制共模电压峰值和减少窄脉冲的产生,提出了一种利用有效电流矢量代替零电流矢量的改进型空间矢量调制策略及其优化的开关调制模式。然后在考虑换流时间的基础上,推导了使用传统空间矢量调制策略搭配不同开关调制模式,及使用改进型空间矢量调制策略时,窄脉冲产生几率与调制度和扇区角度的关系表达式。理论分析证明,所提算法不仅对共模电压幅值、有效值和谐波含量有明显的抑制效果,还可在更宽的调制度范围内获得较优的输入、输出性能。仿真和实验结果验证了算法的可行性和有效性。针对AC-DC矩阵变换器抗电网畸变能力较差的问题,首先定量分析了AC-DC矩阵变换器在电源电压幅值不平衡和波形非正弦情况下的工作特性,推导了输入、输出各电量的解析表达式。然后提出了一种αβ坐标系下空间矢量调制策略的通用实现方法,其特点是可以灵活构造期望输入电流矢量,改变AC-DC矩阵变换器的工作特性。最后以获得平直的输出直流电压为目的,提出了一种期望输入电流矢量的构造方法,可以同时补偿电源电压矢量幅值和角速度不恒定造成的输出直流电压脉动。同时,该补偿控制策略有效减少了开平方、三角函数和反三角函数等复杂运算的次数,更利于工程实现。理论分析的正确性和算法的可行性得到了仿真实验的验证。提出了一种基于空间矢量表达和滑模变结构的非线性控制策略。推导了AC-DC矩阵变换器的误差状态空间模型,讨论了滑模切换线的选取方法,给出了滑动模态的可到达条件并设计了开关表。着重研究了控制器参数对变换器性能的影响,从最大化滑模存在域宽度和降低开关频率的角度出发,给出了控制器参数选择方法。实验结果证明,基于本控制策略的AC-DC矩阵变换器具有算法简单、无稳态误差、动态响应速度快、抗网侧干扰能力强和输入功率因数高等优点。输入LC滤波器是AC-DC矩阵变换器中不可或缺的重要组成部分,但是其固有的谐振特性易被电源电压中的谐波污染或输入电流中的谐波分量激发,造成变换器无法正常工作。为了在抑制输入滤波器谐振的同时,改善AC-DC矩阵变换器的运行特性,提出了一种两相同步旋转坐标系下的双闭环反馈控制策略。分别利用单周期控制技术和经典控制理论设计了输入电流内环控制器和负载电压外环调节器,并从数学的角度讨论了单周期控制策略与空间矢量调制策略的异同点。提出了一种具有选频特性的主动阻尼控制策略,并将其与输入电流内环控制器相结合,避免了类似算法中复杂的归一化和三角函数运算,降低了软件复杂度。在考虑实际控制器延时的基础上,分析了控制器参数对系统稳定性的影响。提出了一种基于DSP和CPLD的单周期控制器实现方法,使得数字化单周期控制成为可能。实验结果验证了所提算法的有效性和数字单周期控制的可行性。本文通过对AC-DC矩阵变换器调制策略和控制策略的研究,得出了一些有意义的经验和结论,为AC-DC矩阵变换器进一步的实用化研究提供了一定的技术基础。
[Abstract]:AC-DC matrix converter is a novel topology of general step-down rectifying device, without the need for large capacity storage devices, so it has the advantages of compact structure, high energy density, reliability and maintainability good advantage, very suitable for weight, volume, efficiency and reliability of applications to higher requirements. At the same time, power the factor of sinusoidal input current can be adjusted up to 1, has a natural regenerative capacity, can output bipolar voltage and turn-on bidirectional current, allowing the load of four quadrant operation, meet the basic requirements of an ideal rectifier. In this paper, theoretical analysis, computer simulation and experiment combination system, in-depth study of the space vector modulation strategy of matrix converter AC-DC, the key technical problems of strategy harmonic suppression methods for nonlinear control model, AC-DC matrix converter provides theoretical support and practical Holding and technical preparation.
This paper from the space vector modulation strategy of matrix converter AC-DC based on in-depth analysis of the relationship between the AC-DC transformation matrix converter. In order to suppress the common mode voltage peak and reduce the narrow pulse generation, proposed switch modulation mode improved space vector modulation strategy is an effective use of current vector instead of zero current vector and then optimized. Considering the commutation time, derived using traditional space vector modulation strategy of different collocation switch modulation mode, and use the improved space vector modulation strategy, the relationship between expression of pulse generation and modulation rate and sector angle. Theoretical analysis proves that the proposed algorithm not only on common mode voltage amplitude, RMS suppression the obvious effect of harmonic content, can also get better input, while the modulation range of output performance. The simulation and experimental results verify the calculation The feasibility and effectiveness of the law.
According to the AC-DC matrix converter power grid anti distortion ability is poor, the quantitative analysis of AC-DC matrix converter in the power supply voltage unbalance and non sinusoidal condition characteristics and waveform, deduces the analytical expression of the output of each input power. Then a new method is proposed to realize the general vector modulation strategy of alpha beta coordinates. The space, which is characterized by flexible structure expected input current vector, change the operating characteristics of AC-DC matrix converter. Finally, in order to obtain the output DC voltage level for the purpose, proposed a method to construct the desired input current vector, the output DC voltage ripple compensation can also supply voltage vector amplitude and angular velocity is not constant cause at the same time, the compensation control strategy can effectively reduce the number of times square, complex calculation of trigonometric and inverse trigonometric function, more conducive to the realization of the project. The correctness of the analysis and the feasibility of the algorithm are verified by the simulation experiment.
This paper presents a nonlinear variable structure space vector expression and sliding mode control scheme based on error. The state space model of AC-DC matrix converter is deduced, the method of selecting the switching line, given the sliding mode reaching conditions and the design of the switching table. Emphatically studied the influence of controller parameters on the performance of the converter and from the maximum sliding domain width and reduce the switching frequency of the angle, gives the controller parameter selection method. Experimental results show that the AC-DC matrix converter control strategy based on a simple algorithm with no steady-state error, fast dynamic response, anti disturbance ability and network side input power factor is high.
The input LC filter is an important part of AC-DC matrix converter, but its inherent resonant characteristics are easily supply voltage harmonic pollution in or in the input current harmonic excitation, resulting in converter can not work normally. In order to suppress the resonance of the input filter at the same time, improve the working characteristics of AC-DC matrix converter. Put forward a double closed loop synchronous rotary coordinate feedback control strategy. Using one cycle control technique and classical control theory to design the input current loop controller and load voltage regulator, and from the angle of mathematics is discussed. One cycle control strategy and the space vector modulation strategy is proposed. The similarities and differences active damping has frequency selective properties of the control strategy, and combine it with the input current loop controller, avoiding the complex and similar normalization algorithm The operation of trigonometric function, reduce the software complexity. In consideration of the actual controller delay, analyzes the influence of controller parameters on the stability of the system. A new method is proposed to realize single cycle controller based on CPLD and DSP, the digital one cycle control possible. Experimental results verify the feasibility and effectiveness of the proposed algorithm. The digital one cycle control.
Based on the research of modulation strategy and control strategy of AC-DC matrix converter, some meaningful experiences and conclusions are obtained, which provide a technical basis for further practical research of AC-DC matrix converter.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM46

【参考文献】