风电接入对配电网继电保护的影响及其保护配置研究

发布时间：2018-01-31 04:29

本文关键词： 双馈异步发电机(DFIG) 配电网电流保护 RTDS/RSCAD纵联差动保护　出处：《广西大学》2014年硕士论文　论文类型：学位论文

【摘要】：环境污染的日益尖锐,化石能源的日益枯竭,促进和加速了新能源的开发和利用。风力发电技术在新能源中技术最为成熟,大规模风电场接入电网成为一种必然趋势。兆瓦级的双馈异步风力发电机(DFIG,简称双馈风机)已经成为目前的主流机型,发展非常迅速。然而,风电接入配电网会改变配电网的拓扑结构,进而会导致功率、潮流分布变得更加复杂,传统配电网电流保护的整定条件发生了变化,引起保护出现灵敏度降低、拒动、误动等一系列的问题,无法满足包含风电的配电网的需求,一定会给电力系统的安全、稳定运行带来极大的隐患。因此,研究风电接入给配电网继电保护带来的影响及保护配置具有重要意义。本文首先从DFIG的工作原理、数学模型以及矢量控制策略这三个方面进行分析,在RTDS/RSCAD平台上建立双馈风机的并网模型,对其并网运行特性及故障特性进行仿真研究,实现功率的解耦控制。其次,从理论上分析了风电接入配电网后对传统电流保护和自动重合闸装置产生的影响及原因,风电接入不同位置以及风电接入不同容量对保护产生的影响。利用RTDS/RSCAD搭建了风电场接入的10kV配电网仿真模型,先对不含风电的配电网模型进行短路电流和保护方案的整定计算及仿真验证。在含风电的模型中,通过设置不同的故障位置、改变风电接入的容量以及线路的长度,仿真验证了风电的接入容量增大到某一定值,会使接入点上游保护误动作,接入点下游保护的电流速断的保护范围增大,无法保证选择性；线路长度的改变也会对保护造成不同程度的影响。最后,针对含风电的配电网采用分区纵联差动保护与过电流保护相配合的新型方法,以10kV配电网系统为对象进行计算和仿真验证。结果证明采用的新方法可以保证保护的可靠性,可以满足风电接入以后对配电网继电保护的要求。
[Abstract]:The increasingly sharp environmental pollution and the depletion of fossil energy promote and accelerate the development and utilization of new energy. The technology of wind power generation is the most mature in the new energy. It is an inevitable trend for large-scale wind farms to connect to the power grid. DFIGs (doubly-fed wind turbines) with megawatt level have become the mainstream models and are developing very quickly. However, wind power access to the distribution network will change the topology of the distribution network, which will lead to power, power flow distribution becomes more complex, the traditional distribution of current protection setting conditions have changed. It can not meet the needs of the distribution network including wind power, which will bring great hidden trouble to the safety and stability of the power system. It is of great significance to study the impact of wind power access on distribution network relay protection and protection configuration. Firstly, this paper analyzes the working principle, mathematical model and vector control strategy of DFIG, and establishes the grid-connected model of doubly-fed fan on RTDS/RSCAD platform. The characteristics of grid-connected operation and fault characteristics are simulated and studied to realize decoupling control of power. Secondly. The influence of wind power on the traditional current protection and automatic reclosing device is analyzed theoretically. Wind power access to different locations and wind power access to different capacity of the impact on the protection. Using RTDS/RSCAD to build a wind farm access to the 10kV distribution network simulation model. First, the short-circuit current and protection scheme of the distribution network model without wind power are calculated and simulated. In the model with wind power, different fault locations are set up. By changing the wind power access capacity and the length of the line, the simulation results show that the access capacity of the wind power increases to a certain fixed value, which will make the upstream protection of the access point malfunction, and the protection range of the current quick break of the downstream protection of the access point will be increased. Selectivity cannot be guaranteed; The change of line length will also cause varying degrees of impact on the protection. Finally, for the distribution network with wind power, a new method of zonal longitudinal differential protection and over-current protection is adopted. The results show that the new method can guarantee the reliability of the protection and can meet the requirements of relay protection after wind power is connected to the distribution network.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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