微电网SPWM单相并网逆变器控制技术研究

发布时间：2019-05-29 12:27

【摘要】：能源危机和环境污染问题加速了人类对可再生能源的研究和开发。新型的分布式电源如太阳能光伏电池、风力发电机组和燃料电池等可再生能源发电是构成微电网重要的分布式电源，分布式发电形式可以实现能源地域互补和资源优化配置。这些分布式电源需经过固定的接口设备并入电网，给远程负载供电，或者直接利用逆变器转换给本地的交流负载供电，因此无论是哪种供电形式都将经过并网逆变器的转换。在现代电力电子技术迅速发展及信息科学技术不断进步的带动下，高新技术产品和用电设备对供电质量提出了越来越严格的要求，因此研究出性能优越、功能完备、可靠性高的并网逆变器就成为人们十分关注的课题。本文主要做了如下几个方面的工作：（1）研究了基于TMS320F28335的SPWM单相并网逆变器控制技术。构建了微电网模型和逆变器仿真模型，分析了逆变器的SPWM的基本概念、调制技术和锁相环的原理。在MATLAB/SIMULINK仿真环境中建立了微电网系统的仿真模型，，仿真结果表明，应用锁相环技术，系统在0.17s内完成逆变电流与电网电压的锁相。随后进行了逆变电路器件的选择以及LC滤波电路的设计。（2）研究了并网逆变器的主电路拓扑结构，分析了系统的工作原理，确定了系统的控制策略。硬件设计方面分别介绍DSP最小系统电路、信号采集模块、IGBT功率驱动模块、人机交互模块、通讯模块；软件设计方面分别介绍系统的主程序、系统时钟的设计、SPWM对称规则采样法的实现、CAP实现锁相环功能等。（3）以SPWM波和逆变电流为测试对象，建立单相并网逆变系统，分别研究了电网电压转换波形质量，SPWM死区设置，载波比不同时的SPWM波形和电网电压与逆变信号的锁相。实验结果与设计理论对比分析结果表明：对称规则采样法的应用能够得到波形质量很好的SPWM波；逆变正弦信号频率为50Hz，正弦信号能与电网电压信号完成锁相，锁相的频率误差为2.5%，在允许波动范围内；单相SPWM并网逆变控制系统结构设计合理、运行稳定，验证了方案的合理性和有效性。
[Abstract]:Energy crisis and environmental pollution accelerate the research and development of renewable energy. New distributed power sources, such as solar photovoltaic cells, wind turbines and fuel cells, are important distributed power sources in microgrid. Distributed power generation can complement each other and optimize the allocation of resources. These distributed power supplies need to be integrated into the power grid through fixed interface equipment to supply power to the remote load, or directly use the inverter to convert to the local AC load power supply, so no matter which power supply form will be converted through the grid-connected inverter. Driven by the rapid development of modern power electronics technology and the continuous progress of information science and technology, high-tech products and electrical equipment have put forward more and more strict requirements for the quality of power supply, so it is found that the performance is superior and the function is complete. High reliability grid-connected inverter has become a very concerned topic. The main work of this paper is as follows: (1) the control technology of SPWM single-phase grid-connected inverter based on TMS320F28335 is studied. The microgrid model and inverter simulation model are constructed. The basic concept of inverter SPWM, modulation technology and the principle of phase-locked loop are analyzed. The simulation model of microgrid system is established in MATLAB/SIMULINK simulation environment. The simulation results show that the phase-locked loop technology is used to complete the phase-locking of inverter current and grid voltage in 0.17s. Then the selection of inverter circuit devices and the design of LC filter circuit are carried out. (2) the main circuit topology of grid-connected inverter is studied, the working principle of the system is analyzed, and the control strategy of the system is determined. In the aspect of hardware design, the DSP minimum system circuit, signal acquisition module, IGBT power drive module, human-computer interaction module and communication module are introduced respectively. In the aspect of software design, the main program of the system, the design of system clock, the realization of SPWM symmetric rule sampling method and the realization of phase-locked loop (PLL) function by CAP are introduced respectively. (3) taking SPWM wave and inverter current as the test object, the single-phase grid-connected inverter system is established, and the voltage conversion waveform quality, SPWM dead time setting, SPWM waveform with different carrier ratio and phase-locking between grid voltage and inverter signal are studied respectively. The experimental results are compared with the design theory. The results show that the SPWM wave with good waveform quality can be obtained by the application of symmetric regular sampling method. The frequency of the inverter sinusoidal signal is 50Hz, and the sinusoidal signal can be phase-locked with the voltage signal of the power grid. The frequency error of the phase-locked signal is 2.5%, which is within the allowable fluctuation range. The single-phase SPWM grid-connected inverter control system has reasonable structure design and stable operation, which verifies the rationality and effectiveness of the scheme.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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