【作者】 刘连光； 王开让； 郭世晓； 赵军； 魏凯； 刘春明；

【Author】 Liu Lian-guang;Wang Kai-rang;Guo Shi-xiao;Zhao Jun;Wei Kai;Liu Chun-ming;State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources (North China Electric Power University);Department of Operation and Maintenance Gansu Electric Power Corporation;

【机构】 新能源电力系统国家重点实验室(华北电力大学)； 甘肃省电力公司运维检修部；

【摘要】 以往500k V电网GIC计算,通常忽略220k V及以下电网的GIC。2005年起,我国西北开始建设的750k V电网普遍采用单相自耦变,变压器原、副边电网的GIC可经自耦变压器的公共绕组及中性点流入流出变压器,研究GIC对750k V变压器的干扰以及基于变压器中性点的GIC治理,变压器副边电网的GIC不可忽略。为探明330k V电网GIC对750k V变压器中性点GIC的贡献,以甘肃电网为例,分别考虑330k V电网、750k V电网和330k V与750k V电网三种情况,分别建立了三种情况电网GIC模型,运用MATLAB计算了三种电网的GIC,并通过对计算结果和原、副边电网GIC相互作用及相互影响分析,探明了750k V与330k V电网GIC相互作用的特征及相互影响的规律,以及330k V电网GIC对750k V变压器中性点GIC的贡献。该项研究工作及成果,对750k V变压器中性点GIC准确计算和中性点GIC治理具有重要的意义。更多还原

【Abstract】 When calculating GIC in a 500 k V power network, GIC in the 220 k V network and below is usually ruled out in previous studies. Since 2005, China has launched the construction of 750 k V power network in the northwest, in which autotransformers are widely used GIC, once induced in such network, is able to flow in or out of the autotransformer through the common winding and the neutral point. Therefore, to analyze the impact of GIC on the 750 k V transformers, and in turn, mitigate GIC in the neutral point, we must take into consideration the influence of GIC in the secondary winding. We took Gansu power network as a testing case to investigate the contribution of GIC from 330 k V network to the GIC in the neutral point of the 750 k V autotransformer. We established network models under three different scenarios, which are respectively 330 k V network alone, 750 k V network alone, and the combination of 330 k V and 750 k V networks. We then calculated GIC under these different scenarios with the same geoelectric field conditions in MATLAB. Analysis was made on the calculation results and the interaction between GIC in primary and secondary windings, which revealed the characteristics and the pattern of the GIC interaction between windings, as well as the contribution of GIC from 330 k V to the GIC in the neutral point of 750 k V autotransformer. Conclusions drew from the research is of great significance for GIC calculation and GIC mitigation strategies in the 750 k V power network.更多还原