【作者】 陈洁；

【导师】 宋吉江；

【作者基本信息】 山东理工大学 ， 电气工程， 2012， 硕士

【摘要】 基于清洁的可再生能源的分布式发电不仅是集中式发电不可缺少的有效补充,而且对于缓解日趋严峻的能源与环境问题具有重大的战略意义。在分布式发电采用的能源中,太阳能的广泛性、无限性和经济性是其他能源所无法比拟的,因此太阳能光伏发电倍受世界各国的重视,并被公认为技术含量高、最有发展前途的技术之一。随着光伏发电技术逐步成熟、发电成本不断降低,光伏系统并网成为太阳能开发利用的主流趋势。然而光伏发电系统的输出功率易受外界环境条件影响。当大规模,高容量的光伏系统并网后必定给配电网带来一系列问题和挑战,其中之一就是对配电网的保护产生影响,因为光伏发电系统并网后改变了原有配电网的网络结构和潮流分布,这可能使得故障电流的大小、流向和持续时间发生变化,直接影响继电装置的保护性能,破坏保护与安全自动装置之间的配合。为了保证配电网的安全稳定运行,也为了推广光伏发电并网技术的应用,本文基于光伏系统并网对配电网保护的影响这一问题展开了研究。本文首先分析了在配电网采用不同保护配置方案的情况下,当系统发生故障时,光伏发电并网系统对其继电保护和安全自动装置的影响。然后在搭建的配电网模型上,采用PSCAD/EMTDC软件进行仿真,针对光伏发电系统从不同位置并网,并网容量不同以及配电网系统发生不同位置的故障等条件下流过配电网的故障电流变化情况来分析光伏发电并网对配电网故障电流的影响。之后依据是否允许孤岛运行,对现有的含光伏电源的配电网保护方案进行分类介绍。提出基于广域测量系统的保护改进方案,该方案对配电网原有的保护配置进行改进并利用广域测量系统收集多点保护动作信息以便综合判断出故障的准确区位,从而防止保护误动。当发生永久性故障时,采用短时间断供电模式形成孤岛运行,充分发挥了光伏电源的积极作用,提高了配电网供电的安全可靠性。更多还原

【Abstract】 The distributed generation based on clean and renewable energy is not only an indispensable and effective complement to centralized power generation, and of great strategic significance to alleviate the increasingly serious energy and environmental issues. Solar energy is unmatched by other energy sources which are used by distributed power generation because of it is broad, unlimited and economy. So the solar photovoltaic power has aroused much worldwide attention, and is recognized with high technological content, as one of the most promising technologies. With photovoltaic technology gradually mature and the cost of power generation reduced ceaselessly, the grid-connected photovoltaic system has become the mainstream trends in solar energy development and utilization. However, the output power of the photovoltaic power generation system is susceptible to external environmental conditions.When the large-scale, high-capacity photovoltaic systems connected the grid must bring distribution network a series of issues and challenges, one of which is the influence on the distribution network protection, because the grid-connected photovoltaic system changes the original network structure and power flow of the distribution network, which may change the fault current magnitude, flow direction and duration,direct impact on the protective properties of the relay device, damage the co-ordination between protection and automatic safety devices. In order to ensure the safe and stable operation of distribution network, as well as to promote the applications of thegrid-connected photovoltaic system technology, The paper launches the research on the effects of grid-connected photovoltaic system on distribution network protection.With the distribution network using different protection configuration scheme,the effects of grid-connected photovoltaic system on relay protection and automatic safety devices when failure occurs are firstly analyzed in the paper. Then distribution network fault current changes are analyzed and the conclusion of the effects of grid-connected photovoltaic system on distribution network fault current is drawn according to different photovoltaic system access locations, different access capacity, different fault locations in distribution network.The existing protection scheme of distribution network with photovoltaic system based on whether to allow the island running to classify and be described.Based on wide area measurement system protection scheme is Proposed. The scheme to improve the existing distribution network protection configuration and use of wide area measurement system to collect multi-point protection action information to conduct the comprehensive determine the accurate location of the fault, thereby preventing protection malfunction.When a permanent fault occurs, a short time off the power supply mode is used to form island running.It gives full play the positive role of the photovoltaic power and improves the safety and reliability of the distribution network power supply.更多还原