单相逆变器输出波形控制技术研究

发布时间：2019-01-18 18:38

【摘要】：近年来,随着社会的发展,现代电力电子技术水平不断提高,各种非线性用电设备的数量和比重都在增加,逆变器的波形控制技术迅速发展,对低谐波、高精密、响应速度快的逆变电源需求逐渐增多,逆变电源的高精度与低谐波性能对保护用电设备和减小逆变电源对电网污染等方面起着巨大的作用,目前存在了各种各样波形控制技术。本文以单相逆变器带非线性负载为研究对象,分析逆变器的几种闭环控制方法来补偿输出波形的畸变,提高输出电压波形质量,研究目标是使逆变器的输出电压波形具有良好的稳态和动态性能。首先建立了单相逆变器的数学模型,分析单相逆变器的输出滤波器参数选择方法,确定了输出滤波器的滤波电感和滤波电容的实际参数,分析了逆变器输出波形产生畸变的各种影响因素。然后通过闭环控制的方法来提高输出波形的质量,介绍了重复控制的原理,对单相逆变器采用重复控制进行时域、频域仿真分析,仿真结果说明重复控制能使系统具有优良的稳态性能,输出电压的THD较低,但重复控制存在一个基波周期的延迟会使系统的响应速度变慢。为了弥补重复控制的缺点,研究了基于重复控制的PI双闭环控制,分析了PI双闭环控制的电流内环的设计方案,时域、频域的仿真分析说明基于重复控制的PI双闭环控制能使逆变器的输出波形系统具有较好的稳态和动态性能,输出电压的THD较低,但是这种复合控制方法的系统稳态性能没有单独重复控制好。基于阻抗调节的重复控制是将重复控制和极点配置结合使用,利用极点配置提高系统的阻尼,改善逆变器的动态性能,降低逆变器的输出阻抗,经过时域、频域的仿真分析,说明基于阻抗调节的重复控制使逆变器的输出波形具有良好的稳态和动态性能,输出电压的THD值比单独重复控制时小。单纯的LC滤波器存在瞬态振荡,通过虚拟阻抗技术增加系统的阻尼,使逆变器输出滤波器具有瞬态振荡抑制效果好、损耗低、易实现等优点。可以在单相逆变器的波形控制仿真和实验中采用虚拟阻抗技术,这样不仅可以消除输出滤波器的瞬态振荡,还能提高逆变器的传输效率,改善输出波形质量。最后根据以上的研究搭建以STM32F407IG型号的ARM控制芯片为核心的实验平台,设计各部分硬件电路,编写各个算法的软件程序,实验结果表明,本文采用的波形控制方法能正确有效地实现本文的研究目标。
[Abstract]:In recent years, with the development of society, the level of modern power electronics technology has been improved, the number and proportion of all kinds of nonlinear power equipment are increasing, the waveform control technology of inverter has developed rapidly, for low harmonic, high precision, The demand of inverter power supply with fast response speed is increasing gradually. The high precision and low harmonic performance of inverter power supply plays a great role in protecting power equipment and reducing the pollution caused by inverter power supply and so on. At present, there are various waveform control techniques. In this paper, the single-phase inverter with nonlinear load is studied, and several closed-loop control methods of inverter are analyzed to compensate the distortion of output waveform and improve the quality of output voltage waveform. The research goal is to make the output voltage waveform of inverter have good steady and dynamic performance. Firstly, the mathematical model of single-phase inverter is established, and the parameter selection method of output filter of single-phase inverter is analyzed, and the actual parameters of filter inductance and filter capacitance of output filter are determined. The factors influencing the distortion of inverter output waveform are analyzed. Then the closed-loop control method is used to improve the quality of output waveform. The principle of repetitive control is introduced, and the time-domain and frequency-domain simulation analysis of single-phase inverter using repetitive control is carried out. The simulation results show that the repetitive control can make the system have good steady-state performance and the THD of output voltage is low, but the response speed of the system will be slowed down by the delay of a fundamental period in the repetitive control. In order to remedy the shortcoming of repetitive control, the PI double closed loop control based on repetitive control is studied, and the design scheme of PI double closed loop current inner loop, time domain, is analyzed. The simulation analysis in frequency domain shows that PI double closed loop control based on repetitive control can make the output waveform system of inverter have better steady-state and dynamic performance, and the THD of output voltage is lower. However, the steady-state performance of this compound control method is not as good as that of repetitive control alone. The repetitive control based on impedance regulation is a combination of repetitive control and pole configuration, which can improve the damping of the system, improve the dynamic performance of the inverter and reduce the output impedance of the inverter. It is shown that the repetitive control based on impedance regulation makes the output waveform of the inverter have good steady and dynamic performance, and the THD value of the output voltage is smaller than that of the single repetitive control. There is transient oscillation in simple LC filter. By increasing the damping of the system by virtual impedance technique, the inverter output filter has the advantages of good transient oscillation suppression effect, low loss and easy to be realized. Virtual impedance technology can be used in the simulation and experiment of single-phase inverter waveform control, which can not only eliminate the transient oscillation of the output filter, but also improve the transmission efficiency of the inverter and improve the quality of the output waveform. Finally, based on the above research, an experimental platform based on STM32F407IG ARM control chip is built, and the hardware circuits are designed, and the software programs of each algorithm are written. The experimental results show that, The waveform control method used in this paper can realize the research goal correctly and effectively.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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