摘要
直流电网可在大范围内平抑可再生能源发电的波动性、间歇性,实现广域范围内、跨地区交流电网的高度互联,是构建未来全球能源互联网的重要形态。然而,直流电网的构建给暂态特性分析与保护策略设计带来新的技术挑战。以基于模块化多电平换流器的对称单极直流电网为研究对象,介绍换流站内部和直流线路的典型故障特性。在此基础上,提出直流电网故障的快速检测方法和保护策略,并给出几种可行的直流电网故障重启策略。最后,通过PSCAD/EMTDC对典型工况下故障保护与重启过程进行仿真分析,验证所提出策略的有效性和可行性。
Being able to stabilize the fluctuation and intermittence of renewable energy power generation in a large range and achieve a highly interconnected trans-regional AC power grid in a wide area, DC power grid is an important form for building the future global energy interconnection. However, the construction of DC power grid brings new technical challenges to the analysis of transient characteristics and the design of protection strategy. Taking the symmetric monopole DC power grid based on modular multilevel converter as the research object, the typical fault characteristics of the converter station and DC lines are introduced. On this basis, the method of rapid detection of DC power grid fault and protection strategy are put forward and several feasible restart strategy of DC power grid fault are given. Finally, the simulation and analysis of fault protection and restart process under typical operating conditions are carried out by PSCAD/EMTDC, which verifies the effectiveness and feasibility of the proposed strategy.
出处
《智能电网》
2016年第10期993-1002,共10页
Smart Grid
