基于内模原理的单相PWM逆变器分数阶相位补偿重复控制技术研究

发布时间：2019-03-09 18:00

【摘要】：常规重复控制提供了一种精确波形控制方案,可以实现任何已知整数周期信号的零稳态误差跟踪,以补偿由参量变化特别是非线性负载引起的谐波失真。其中,重复控制系统要求外部控制信号周期必须是采样周期的整数倍,然而,它不总是满足于实际应用。当延迟指数项出现分数阶时,常规重复控制不能精确地跟踪控制周期信号,引起电力电子器件控制性能的显著下降。为此,本文采用内嵌拉格朗日插值算法的低通滤波器逼近分数阶指数,提出了基于内模原理的分数阶相位补偿重复控制技术。在固定采样频率下,所述分数阶相位补偿重复控制为滞后非整数项提供了解决方案。论文以电压型单相全桥恒压恒频PWM逆变器的波形控制为研究平台,首先建立和分析逆变器状态空间方程,给出了滤波电路参量的选择条件。然后阐述线性反馈控制的控制原理,论述常规重复控制原理,并分析其系统特性,以此为基础,引入分数阶相位补偿重复控制器,继而详细分析分数阶相位补偿重复控制系统的设计原理及系统特性。为了验证所提分数阶相位补偿重复控制器的精准性和优越性,在仿真环境中分别进行了线性反馈控制系统、常规重复控制系统和所提控制系统的对比仿真实验。此外,搭建了以DSP为控制系统的单相PWM逆变器实验平台,并介绍包含采样电路、驱动电路等硬件电路的选取分析,同时分析包含主程序、ADC采样、SPWM产生及控制器程序的软件设计。最后,实验波形和数据验证了分数阶相位补偿重复控制器的精准性和优越性。
[Abstract]:Conventional repetitive control provides an accurate waveform control scheme which can track the zero steady-state error of any known integer periodic signal to compensate the harmonic distortion caused by the variation of parameters especially the nonlinear load. The repetitive control system requires that the period of the external control signal must be an integer multiple of the sampling period, but it is not always satisfied with the practical application. When the delay index term appears fractional order, the conventional repetitive control can not accurately track the control periodic signal, which results in the significant degradation of the control performance of power electronic devices. In this paper, the low-pass filter with embedded Lagrangian interpolation algorithm is used to approximate the fractional exponent, and a fractional phase compensated repetitive control technique based on the internal model principle is proposed. At a fixed sampling frequency, the fractional phase compensated repetitive control provides a solution for the delay non-integer term. Based on the waveform control of the voltage-type single-phase full-bridge constant-voltage and constant-frequency PWM inverter, the state space equation of the inverter is established and analyzed firstly, and the selection conditions of the filter circuit parameters are given. Then the control principle of linear feedback control is expounded, and the principle of conventional repetitive control is discussed, and the characteristics of the system are analyzed. On the basis of this, fractional phase compensated repetitive controller is introduced. Then the design principle and characteristics of fractional phase compensated repetitive control system are analyzed in detail. In order to verify the precision and superiority of the proposed fractional phase compensated repetitive controller, the comparative simulation experiments of the linear feedback control system, the conventional repetitive control system and the proposed control system are carried out in the simulation environment. In addition, the experiment platform of single-phase PWM inverter with DSP as control system is built, and the selection and analysis of hardware circuits including sampling circuit, driving circuit and so on are introduced. At the same time, the main program, ADC sampling, and so on are analyzed. SPWM generation and software design of controller program. Finally, the experimental waveform and data verify the precision and superiority of the fractional phase compensation repetitive controller.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

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