含分布式光伏电源的配电网继电保护研究

发布时间：2018-06-13 18:20

本文选题：分布式光伏电源 + 低电压穿越　；参考：《南京理工大学》2017年硕士论文

【摘要】：近年来,利用太阳能的光伏发电技术得到了快速的发展,并且在商业和工业化应用中日趋成熟。预计在未来的几年内,我国电网中光伏电源的数量将大幅增长。然而,大量分布式光伏电源的接入会给配电网的安全稳定运行带来一些不利的影响。传统的配电网保护无法适用于含分布式光伏电源的配电网,可能产生误动或者拒动。分析了光伏并网逆变器基于电网电压定向的控制策略,并根据国内外对光伏并网发电系统的低电压穿越的技术要求,研究了基于无功电流支撑的光伏并网系统低电压穿越控制策略。该控制策略能够保证光伏电源在并网点电压跌落时的输出电流不过流,并向电网提供一定无功功率,同时,根据光伏并网系统的低电压穿越控制策略建立了光伏电源的短路计算模型。基于光伏电源的压控电流源等效模型,分析了含分布式光伏电源的配电网的故障特性,研究了含分布式光伏电源的配电网故障分析方法。通过仿真验证了该故障分析方法能够正确计算含分布式光伏电源配电网中故障电流的大小与相位。根据含光伏电源配电网的故障特性,分析了分布式光伏电源的接入对配电网传统方向元件的影响,并在此基础上研究了适用于含分布式光伏电源配电网的方向元件判据,通过仿真验证了该方向元件判据的有效性。最后,在能正确判别故障方向的基础上,提出了适用于含多个光伏电源的配电网自适应正序电流速断保护。通过仿真验证了该保护方案可根据光伏电源容量、发生故障位置的不同,实现自适应在线保护整定,能够有效提高本地保护范围,有较好的实用性。
[Abstract]:In recent years, solar photovoltaic power generation technology has been rapid development, and in commercial and industrial applications are increasingly mature. In the next few years, the number of photovoltaic power supply in China's power grid is expected to increase significantly. However, the access of a large number of distributed photovoltaic power sources will bring some adverse effects to the safe and stable operation of the distribution network. Traditional distribution network protection can not be applied to distribution network with distributed photovoltaic power, which may cause maloperation or rejection. This paper analyzes the control strategy of grid-connected photovoltaic inverter based on grid voltage orientation, and according to the technical requirements of low-voltage traversing of photovoltaic grid-connected generation system at home and abroad. The low voltage traversing control strategy of photovoltaic grid-connected system based on reactive current support is studied. The control strategy can ensure that the output current of photovoltaic power supply is not only current but also provide a certain amount of reactive power to the power grid, at the same time, According to the low voltage traversing control strategy of photovoltaic grid-connected system, the short-circuit calculation model of photovoltaic power supply is established. Based on the equivalent model of voltage-controlled current source of photovoltaic power supply, the fault characteristics of distribution network with distributed photovoltaic power supply are analyzed, and the fault analysis method of distribution network with distributed photovoltaic power source is studied. The simulation results show that the fault analysis method can correctly calculate the magnitude and phase of the fault current in the distribution network with distributed photovoltaic power. According to the fault characteristics of distribution network with photovoltaic power supply, the influence of the access of distributed photovoltaic power source on the traditional directional elements of distribution network is analyzed, and the criterion of directional component suitable for distribution network with distributed photovoltaic power source is studied. The validity of the criterion is verified by simulation. Finally, based on the correct identification of fault direction, an adaptive positive sequence current fast break protection is proposed for distribution network with multiple photovoltaic sources. The simulation results show that the protection scheme can realize adaptive on-line protection setting according to the capacity of photovoltaic power supply and the different fault location. It can effectively improve the local protection range and has good practicability.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM77

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