光伏MPPT技术及孤岛检测技术研究

发布时间：2018-01-10 17:36

本文关键词：光伏MPPT技术及孤岛检测技术研究　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

更多相关文章： MPPT 自适应 锁相环 孤岛检测

【摘要】：随着社会整体生活水平的提高,与之带来的便是人们对资源依赖的程度逐渐加强,特别是对电力的需求早已不同往日,而过度的开采已加剧了传统资源的消耗速度。近几年,各国为了自身能更好地发展,且出于对下一代负责和对环境保护的目的,加快了对新能源研究的步伐,而光伏发电系统当然是其中不可缺少的一部分。本文首先搭建了光伏电池工程用数学模型来分析其在不同外界环境条件下的输出特性,为后续研究内容作好基础。接着研究光伏电池最大功率跟踪(MPPTT),先分析了其算法原理,接着介绍了几种传统最大功率跟踪算法,然后介绍了一种自适应扰动观测法,但其表现效果离理想效果仍有一些差距,为此,本文以扰动观测法为基础提出了基于变步长和死区相结合的改进型MPPT,其能更好地兼顾跟踪精度和跟踪时间。最后,通过仿真模型验证了所提算法的正确性和有效性。在单相光伏并网控制技术的内容中,通过详细分析,得出基于SOGI的单相锁相环存在着微小偏差量,该偏差量会使系统产生二次谐波,从而影响锁相的准确性,特别当电压发生突变时,其易失去锁相能力。因此,本章在锁相环节中加入陷波器来滤除二次谐波,从而使锁相效果更具准确性。通过对比,在以电网作为扰动源的情况下,得出基于PR调节器的电网电压前馈补偿策略更好地适用于并网系统中。最后,通过仿真模型验证了所研究内容。最后一章分析了孤岛效应发生机理,介绍了一些常见的被动式、主动式孤岛检测方法,着重分析了主动频率偏移法,在其基础上,研究了正反馈主动频率偏移法,为了更进一步地提高检测效果,本文模仿自适应思想,通过结合变步长和限制值来研究变反馈系数主动频率偏移法,其能更好地兼顾检测时间和输出电流的总体谐波失真。然后分析了不可检测区域,通过对比分析,得出了基于Qfo×Cnorm坐标系的盲区分析能更好地反映负载的真实情况以及主动式孤岛检测法的有效性。最后,通过仿真模型验证了所研究内容及方案的正确性和有效性。
[Abstract]:With the improvement of the living standard of the whole society, the degree of people's dependence on resources is gradually strengthened, especially the demand for electricity has long been different. In recent years, for their own better development, and for the purpose of being responsible for the next generation and environmental protection, countries have accelerated the pace of research on new energy. Photovoltaic power generation system is of course an indispensable part of it. Firstly, a mathematical model of photovoltaic cell engineering is built to analyze the output characteristics of photovoltaic cell under different environmental conditions. Then the maximum power tracking algorithm of photovoltaic cell MPPTT is studied. Firstly, the principle of MPPTT algorithm is analyzed, and then several traditional maximum power tracking algorithms are introduced. Then an adaptive perturbation observation method is introduced, but the performance of the method is still far from the ideal effect. Based on the perturbation observation method, an improved MPPTs based on the combination of variable step size and dead zone is proposed in this paper, which can better balance the tracking accuracy and tracking time. Finally. The simulation model verifies the correctness and effectiveness of the proposed algorithm. In the content of single-phase photovoltaic grid-connected control technology, through detailed analysis, it is concluded that there is a small deviation in single-phase phase-locked loop based on SOGI. This deviation will make the system produce second harmonic, which will affect the accuracy of phase lock, especially when the voltage changes, it is easy to lose the ability of phase locking. Therefore, in this chapter, a notch filter is added to the phase-locked loop to filter the second harmonic. In order to make the effect of phase locking more accurate. Through the comparison of the power grid as a disturbance source, it is concluded that the voltage feedforward compensation strategy based on PR regulator is more suitable for grid-connected system. Finally, the mechanism of islanding effect is analyzed, some common passive and active detection methods are introduced, and the active frequency offset method is emphatically analyzed. On the basis of this, the positive feedback active frequency offset method is studied. In order to improve the detection effect further, this paper simulates the adaptive idea. By combining the variable step size and the limiting value to study the variable feedback coefficient active frequency offset method, it can better balance the detection time and the total harmonic distortion of the output current. Then, the non-detectable region is analyzed and analyzed by comparison. The blind area analysis based on Qfo 脳 Cnorm coordinate system can better reflect the real situation of the load and the effectiveness of the active islanding detection method. Finally. The correctness and validity of the research content and scheme are verified by simulation model.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615

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