基于双闭环准比例谐振控制的逆变器研究

发布时间：2018-12-16 02:07

【摘要】：逆变器作为不间断电源、光伏发电系统等系统的核心,其控制算法决定了逆变器的性能、关系到整个系统的运行状态。目前,逆变器多采用PID控制算法,不能实现逆变器的无静差调节。针对此问题,本文提出了一种双闭环准比例谐振控制方式,并以dsPIC单片机为核心设计了实验样机,对控制算法进行了验证,结果表明本文提出的控制算法可以实现逆变器的无静差调节。本文的主要内容如下：首先对单相逆变器的数学模型进行分析,通过平均状态分析方法对单极性SPWM控制的逆变器进行建模,在简化模型的基础上,将逆变器的设计分为滤波器、电流内环控制器、电压外环控制器三个部分,建立了可适应多种控制算法的单相逆变器双环控制模型。在此基础上,对LC滤波器进行了设计,对比分析了比例谐振控制器和准比例谐振控制器的特性,建立了基于双闭环准比例谐振控制器的控制算法,分析了电流内环和电压外环的开环、闭环频率特性以及准比例谐振控制的无静差控制性能。其次,建立了双闭环准比例谐振控制逆变器的MATLAB仿真模型,对逆变器在满载、半载、阻感性负载及非线性负载情况下的稳态和动态特性进行仿真,验证了双闭环准比例谐振器的控制效果。最后,对逆变器的硬件电路进行设计,分析了控制电路、采样电路、驱动电路、采样信号滤波电路的设计原理,结合dsPIC单片机进行软件设计,搭建了实验样机,并在低压下进行了算法验证调试。
[Abstract]:As the core of uninterruptible power supply and photovoltaic system, the control algorithm of inverter determines the performance of inverter and relates to the running state of the whole system. At present, most inverters adopt PID control algorithm, which can not realize the static error regulation of the inverter. In order to solve this problem, a double closed loop quasi-proportional resonance control method is proposed in this paper. The experimental prototype is designed with dsPIC microcontroller as the core, and the control algorithm is verified. The results show that the proposed control algorithm can realize the static error control of the inverter. The main contents of this paper are as follows: firstly, the mathematical model of single-phase inverter is analyzed, and the unipolar SPWM inverter is modeled by the average state analysis method. The inverter is divided into three parts: filter, current inner loop controller and voltage outer loop controller. On this basis, the LC filter is designed, the characteristics of the proportional resonance controller and the quasi-proportional resonance controller are compared and analyzed, and the control algorithm based on the double closed loop quasi-proportional resonance controller is established. The open-loop and closed-loop frequency characteristics of current inner loop and voltage outer loop and the static error control performance of quasi-proportional resonance control are analyzed. Secondly, the MATLAB simulation model of double closed loop quasi-proportional resonant control inverter is established, and the steady and dynamic characteristics of the inverter under full load, half load, resistive load and nonlinear load are simulated. The control effect of double closed loop quasi-proportional resonator is verified. Finally, the design principle of the control circuit, sampling circuit, driving circuit and sampling signal filter circuit is analyzed. The software design of the inverter is combined with the dsPIC microcontroller, and the experimental prototype is built. The algorithm is validated and debugged at low voltage.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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