直流输电新型分布式接地极的优化设计

Optimization Design of Distributed HVDC Ground Electrode

为改善直流输电工程单极大地运行方式容易造成变压器直流偏磁问题,突破直流极接地性能的设计局限,提出了一种直流输电分布式接地极设计方案。研究了三种分布式接地极的仿真模型,并用实例分析了三者的区别,简化计算模型可以取得与完整计算模型一致的结果,从而减少了仿真计算的规模。提出了基于全局最优位置混沌粒子群算法的分布式接地极选址优化方法,并以一个交直流混联电网为例研究了优化选址的效果。本文还以该交直流混联电网为例说明了分布式接地极的实际应用方案,并分析了分布式接地极的电流分布,对交流电网内变压器直流偏磁的缓解作用,为分布式接地极的应用提供参考。

To overcome the limitations of HVDC ground electrodes in dc bias of transformer and grounding performance, design concept of distributed groundelectrodes is put forward in this paper. Three kinds of distributed groundelectrodes simulation models are discussed and the difference between them is analyzed with practical examples. The complete calculation model and the simplified calculation model can achieve the same results, but the results of the circuit model may has obvious error because of the ignorance of sub-electrode mutual-resistance. A newly established HVDC electrode based on the global optimal position chaos particle swarm optimization algorithm and an optimization method of substation site selection are proposed, the effect of substation site selection optimization is studied by taking Hubei AC/DC hybrid power grid as an example. Practical application of the distributed groundelectrodes is shown taking the example of Hubei power grid. Current distribution, relief for HVDC magnetic biasing of transformers in power grid and impact on the environment of distributed groundelectrodes are analyzed, which provides reference for the application of the distributed groundeleetrodes.