单相并网逆变系统控制技术的研究

发布时间：2018-06-23 10:08

本文选题：单相并网 + 电流闭环　；参考：《天津工业大学》2016年硕士论文

【摘要】：随着能源和环境问题的日益严峻,风力发电、光伏发电等新型可再生能源因其具有不消耗化学能源、资源储备近乎无限、不污染环境等优势受到世界范围内的广泛关注。目前,并网逆变器因其在整个与电网相连的并网发电系统中的所起到的重要作用逐渐成为国内外学者研究的重心。课题对单相并网逆变系统中的控制方式、电网信息同步算法等关键技术进行了深入探索与分析,以期提高并网逆变器在整个系统中所表现出来的综合性能。首先,本课题分析了并网逆变系统的具体原理和工作流程,在研究现有控制方案的基础上提出基于数字式的固定开关周期的电流滞环控制算法,对其工作机理进行了详细阐述并推导了开关周期和电流纹波随电网相角的分布规律。进一步提出基于数字式变采样周期的固定开关周期的电流控制方案,以提高系统的整体运行性能,并以所获得的理论分析结果为基础获得了采样周期的在线调整依据。其次,对传统增强型锁相环的工作原理及其在非理想电网条件下的工作特性进行详细的理论分析,针对传统锁相环在电网含有谐波和因模拟器件的非线性等原因造成采集到的数据发生直流偏移时无法准确锁定电网信息的问题,提出基于延时移相相减和戈策尔滤波器的增强型锁相环算法,以实现在非理想电网条件下电网基波中相角、频率和幅值的准确在线估计,以提高系统对电网扰动和畸变的鲁棒性。再次,在对课题所提出的基于数字式变采样周期的固定开关周期的电流滞环控制方法和基于延时移相相减和戈策尔滤波的增强型锁相环算法的研究之上,获得了整个系统设计的总体方案,利用Matlab软件中的Simulink模块来构造基于数字式变采样周期的准固定开关周期的电流滞环控制方法和基于混合滤波的增强型锁相环算法的系统仿真方案,对所提出的数字式电流滞环控制方法、锁相环算法及系统整体结构进行了详细的仿真验证。最后,以数字式信号处理芯片中的TMS320F28335为控制主体,构造了全数字化单相并网逆变系统终端平台,给出了系统关键器件参数的详细设计方案以及软件程序的流程,对所提出的数字式电流滞环控制方案、基于混合滤波的增强型锁相环算法以及整个系统进行了详细的实验验证,给出了系统在论文提出的控制方案和改进的增强型锁相环算法时相对应的实验波形,证明系统并网性能。
[Abstract]:With the increasingly serious energy and environmental problems, new renewable energy sources, such as wind power, photovoltaic power generation and so on, have attracted worldwide attention because of their advantages of not consuming chemical energy, almost unlimited resource reserves, and not polluting the environment. At present, grid-connected inverter has gradually become the focus of research for its important role in the whole grid-connected generation system. The key technologies of single-phase grid-connected inverter system, such as the control mode of single-phase grid-connected inverter system and the information synchronization algorithm of power network, are deeply explored and analyzed in order to improve the comprehensive performance of grid-connected inverter in the whole system. Firstly, the principle and working flow of grid-connected inverter system are analyzed, and a digital hysteresis current control algorithm based on fixed switching cycle is proposed based on the research of existing control schemes. The working mechanism is described in detail and the distribution law of the switching period and current ripple with the phase angle of the grid is deduced. Furthermore, a current control scheme based on digital variable sampling period for fixed switching cycle is proposed to improve the overall performance of the system. Based on the obtained theoretical analysis results, the on-line adjusting basis of the sampling period is obtained. Secondly, the working principle of the traditional enhanced PLL and its working characteristics under the condition of non-ideal power grid are analyzed in detail. In view of the problem that the traditional PLL can not accurately lock the power network information when it contains harmonics and because of the nonlinearity of analog devices, the collected data can not be accurately locked when DC offset occurs. An enhanced phase-locked loop algorithm based on time-delay phase-shift subtraction and Gozel filter is proposed to realize the accurate on-line estimation of the phase angle, frequency and amplitude of the fundamental wave in the power network under non-ideal conditions. In order to improve the robustness of the system to the disturbance and distortion of the power system. Thirdly, the current hysteresis control method based on digital variable sampling period and the enhanced phase-locked loop algorithm based on delay-phase shift subtraction and Gozel filter are studied. The overall scheme of the whole system design is obtained. The Simulink module in Matlab software is used to construct the current hysteresis control method based on digital variable sampling period and the system simulation scheme of enhanced phase-locked loop algorithm based on hybrid filter. The digital hysteresis control method, the phase-locked loop algorithm and the overall structure of the system are simulated and verified in detail. Finally, a digital single-phase grid-connected inverter terminal platform is constructed with TMS320F28335 in the digital signal processing chip as the main control body. The detailed design scheme of the key device parameters and the flow chart of the software program are given. The proposed digital hysteresis current control scheme, the enhanced phase-locked loop algorithm based on hybrid filter and the whole system are verified in detail. The experimental waveforms corresponding to the proposed control scheme and the improved enhanced phase-locked loop algorithm are given, and the performance of the system is proved.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM464

【相似文献】