三相光伏并网逆变器重复控制策略研究

发布时间：2018-03-16 17:13

本文选题：光伏并网逆变器　切入点：软件锁相环　出处：《山东大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着能源危机日趋加剧,清洁和可再生能源逐渐成为人们关注的重点话题,并且得到了世界范围的密切关注。在人们的日常生活中我们利用比较多的清洁能源有水能发电电、风能等等,相比而言太阳能的优势更加的突出,比如无污染,应用的范围广等,所以太阳能也十分受到人类的重视。但作为一种新的能源形式其在发电的方式上还是与传统方式存在很大的差异。第一,光伏电池形成的电能具有显著的非线性特征,为了保证光伏发电的效率最高,需要及时的对其电池放电最大功率点进行跟踪(MPPT)。第二,光伏发电系统属于典型的分布式发电,其产生的大部分能量需要通过电网进行传输,所以需要加大研究相应的光伏发电并网技术。在光伏并网逆变控制上,单纯的依靠传统的PI控制并不能起到很好的效果,本文根据研究的需要提出了一种新的控制方案,即PI控制与重复控制相结合的方式,并进一步的提出了采用TMS320LF2407芯片来保证系统中的并网电流与电网电压保持同步的控制,保证其可靠性。并构建了仿真模型进行深入的研究与分析,实验结果表明,在本研究提出的控制方式下,并网电流可以最大程度上实现与给定电流的跟踪,对于电流波形进行了良好的控制,其谐波畸变率极大的降低,小于5%,符合国家对于逆变器并网的规定。最后在10Kw光伏并网逆变器平台上进行了实验,实验结果证明上述方案明显降低了总谐波畸变率(THD)值。
[Abstract]:With the worsening of the energy crisis, clean and renewable energy has gradually become the focus of attention, and has been paid close attention around the world. In our daily life, we use more clean energy to generate electricity from water, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity, electricity and electricity. Wind energy and so on. Compared with solar energy, the advantages of solar energy are more prominent, for example, no pollution, a wide range of applications, etc. So solar energy is also paid much attention to by human beings. But as a new form of energy, there is still a great difference between the power generation mode and the traditional way. First, the electric energy formed by photovoltaic cells has remarkable nonlinear characteristics. In order to ensure the highest efficiency of photovoltaic power generation, it is necessary to track the maximum power point of its battery discharge in time. Second, photovoltaic power generation system is a typical distributed generation system, and most of the energy generated by the photovoltaic system needs to be transmitted through the power grid. Therefore, it is necessary to study the corresponding grid-connected photovoltaic technology. In photovoltaic grid-connected inverter control, simply relying on the traditional Pi control can not play a good effect. This paper puts forward a new control scheme according to the need of the research. That is the combination of Pi control and repetitive control. Furthermore, a TMS320LF2407 chip is proposed to ensure the synchronization of grid-connected current and grid voltage in the system. The simulation model is constructed for further research and analysis. The experimental results show that the grid-connected current can track the given current to the maximum extent under the control mode proposed in this study. The current waveform is well controlled, and the harmonic distortion rate is greatly reduced, less than 5, which accords with the national regulation of grid-connected inverter. Finally, the experiment is carried out on the 10KW photovoltaic grid-connected inverter platform. The experimental results show that the total harmonic distortion rate (THD) is significantly reduced by the proposed scheme.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM464;TM615

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