基于低压配网电压质量的光伏并网逆变器的控制方法研究

发布时间：2018-08-06 14:44

【摘要】：随着化石能源的日益枯竭和环境问题的日益凸显,开发清洁能源已成为当代趋势。太阳能以其独特优点作为理想的绿色能源受到国内外研究学者的青睐,光伏并网发电技术得到迅速发展。在分布式发电系统中,并网逆变器起着至关重要的作用,其控制策略决定着配电网的电能质量和光伏并入电网的容量、光伏在电网中的渗透率,因此本文针对并网逆变器的控制方法进行研究。首先,论文对不同分类的光伏并网逆变器的拓扑结构进行讨论,并根据分布式光伏发电接入配电网系统的特点,建立了本文研究中所采用的分布式光伏发电系统的拓扑类型。其次,为了减少接入的分布式光伏电源对公共电网的污染,提高配电网的电压质量,本文分析了光伏电源并入配电网引起电压质量问题的机理,通过讨论传统的改善配电网电压质量的措施及其局限性,提出了通过控制逆变器的方法解决光伏并入配电网引起的电压质量问题是当代的研究热点。针对配电网电路R/X值远大于输电线路的特点,初步提出了限制光伏电源并入配电网的有功出力的设想,并对该设想的合理性和可行性展开了推理研究。最后经过对比分析国内外电力专家提出的各种光伏并网逆变器的控制方法,综合考虑配电网电压质量、网络损耗、线路容量、逆变器容量、功率因数等限制条件,优化了传统的控制策略,提出了改进的光伏并网逆变器的控制方法,并通过仿真对该控制策略的有效性进行验证。
[Abstract]:With the increasingly depletion of fossil energy and the increasingly prominent environmental problems, the development of clean energy has become a contemporary trend. Solar energy with its unique advantages as an ideal green energy has been favored by domestic and foreign researchers, photovoltaic grid-connected power generation technology has been rapid development. In distributed generation system, grid-connected inverter plays an important role. Its control strategy determines the power quality of distribution network, the capacity of PV integrated into the grid, and the permeability of photovoltaic in the grid. Therefore, the control method of grid-connected inverter is studied in this paper. Firstly, the topology of grid-connected photovoltaic inverter with different classification is discussed, and according to the characteristics of distributed photovoltaic generation connected to distribution network system, the topology type of distributed photovoltaic power generation system is established in this paper. Secondly, in order to reduce the pollution caused by the connected distributed photovoltaic power supply and improve the voltage quality of the distribution network, this paper analyzes the mechanism of the voltage quality problem caused by the incorporation of the photovoltaic power source into the distribution network. By discussing the traditional measures to improve the voltage quality of distribution network and its limitations, it is proposed that the method of controlling the inverter to solve the voltage quality problem caused by the incorporation of photovoltaic into the distribution network is a hot research topic. In view of the fact that the R / X value of the distribution network circuit is far greater than that of the transmission line, the assumption of limiting the active power output of the photovoltaic power supply into the distribution network is put forward preliminarily, and the rationality and feasibility of the assumption are studied. Finally, by comparing and analyzing the control methods of various photovoltaic grid-connected inverters proposed by domestic and foreign power experts, considering the voltage quality of distribution network, network loss, line capacity, inverter capacity, power factor and so on, comprehensive consideration of the distribution network voltage quality, network loss, line capacity, inverter capacity, power factor, etc. The traditional control strategy is optimized, and the improved control method of grid-connected photovoltaic inverter is proposed, and the effectiveness of the control strategy is verified by simulation.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

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