基于灵敏度分析的直流输电接地极优化选址方法研究

为了最大程度避免直流输电工程单极大地运行方式造成的变压器直流偏磁问题,提出了一种直流输电接地极的优化选址方法。研究了直流接地极选址时需要考虑的大地电性参数、电力规划需求、周边交流电网的结构与参数等因素,建立了直流接地极位置与变压器直流偏磁风险之间的关联度模型。对此模型进行了灵敏度分析,并以此为依据,提出了高压直流输电接地极选址优化方法。以一个交直流混联电网为例研究了优化选址的效果。优化方法对避免交流电网变压器直流偏磁风险有理论参考作用。

Optimization method of grounding pole location for HVDC transmission system based on sensitivity analysis

In order to avoid the DC bias of transformer caused by HVDC project, a method for optimal location of HVDC grounding electrode is proposed. After studying the influence factors of the DC grounding location that should be considered, such as the earth electrical parameters, power planning requirements, structure and parameters of surrounding AC power network and so on, this paper establishes a correlation model between the DC grounding pole position and transformer DC bias risk. Secondly, it makes the sensitivity analysis and on this basis puts forward the HVDC grounding pole location optimization method. Finally, an AC/DC hybrid power grid is used as an example to verify the effect of the proposed method. The optimization method has theoretical reference for avoiding the DC bias risk of AC grid transformer. This work is supported by Science and Technology Project of State Grid Anhui Electric Power Company and Natural Science Foundation of Xinjiang Uygur Autonomous Region (No. 2017D01C417).