含大规模风电接入的柔性直流电网启动控制策略研究

发布时间：2019-01-20 08:39

【摘要】：当今世界的能源结构正在发生转变,可以预见,在电力系统未来数十年的发展中,可再生能源将逐步取代传统化石能源成为电力供给的主要来源。在这个过程中,如何实现可再生能源的大规模并网,提高地区电网对可再生能源的消纳能力是世界能源发展所要面临的难题。随着柔性直流输电的快速发展,以此技术为基础构建的直流电网将有效解决上述问题。本文对含大规模风电的柔性直流电网的启动过程进行了研究,首先考虑了单个换流站的充电过程,分别对有源换流站经交流侧和无源换流站经直流侧进行预充电的原理进行了分析;然后对风电场经柔性直流输电接入电网的技术进行了研究,分别设计实现了风场侧换流站的无源逆变控制策略和风电并网控制策略;最后,以张北柔性直流电网示范工程为背景,讨论了多个换流站经架空线及高压直流断路器完成组网后整个系统的协调启动控制策略,分别对常规情况及几种典型运行方式切换下的直流电网启动流程进行了设计。以上研究工作在进行过程中均在PSCAD/EMTDC中搭建了相应的仿真模型,对理论分析的正确性及控制策略的有效性进行了验证。
[Abstract]:Nowadays, the energy structure of the world is changing. It can be predicted that renewable energy will gradually replace the traditional fossil energy as the main source of power supply in the future decades of power system development. In this process, how to realize the large-scale grid connection of renewable energy and improve the capacity of regional power grid to absorb renewable energy is a difficult problem for the development of energy resources in the world. With the rapid development of flexible DC transmission, the DC network based on this technology will solve these problems effectively. In this paper, the start-up process of flexible DC network with large-scale wind power is studied. Firstly, the charging process of a single converter station is considered. The principle of precharging of active converter station via AC side and passive converter station via DC side is analyzed respectively. Then, the technology of connecting wind farm to grid through flexible direct current transmission is studied, and the passive inverter control strategy of wind field side converter station and the control strategy of wind power grid connection are designed and realized respectively. Finally, taking the demonstration project of Zhangbei flexible DC network as the background, the coordinated startup control strategy of the whole system after several converter stations have completed the networking through overhead lines and HVDC circuit breakers is discussed. The starting process of DC network under normal operation and several typical operation modes is designed. In the process of the above research, the corresponding simulation models are built in PSCAD/EMTDC, and the correctness of the theoretical analysis and the effectiveness of the control strategy are verified.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM721.1

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