±800kV晋北-南京特高压直流输电对安徽电网交流变压器直流偏磁影响分析与治理

Analysis and Control of the DC Magnetic Bias Influence on Anhui Power Grid in ± 800kV Jinbei-Nanjing UHVDC Project

为分析±800kV晋北-南京特高压直流输电工程产生的直流偏磁对安徽电网交流变压器的影响,文章基于场路耦合方法,建立安徽交流电网直流电流分布模型,实测获得安徽地区典型土壤电阻率,仿真分析了直流接地极注入5000A入地电流后安徽电网220kV及以上变电站的直流偏磁情况,根据仿真计算结果提出了相应的治理措施,并结合工程启动调试,开展了治理前后的直流偏磁电流测试,验证了治理措施的有效性。

Based on the field road coupling method, the DC current distribution model of Anhui power grid was established to analyze the influence of DC magnetic bias on AC Transiormers of Anhui power grid in ±800kV Jinbei-Nanjing UHVDC project. The typical soil resistivity in Anhui region was measured and the DC bias, at substations of 220kV and above, was analyzed after the DC earth pole being charged 5000A through simulation. According to the results, corresponding control measures were put forward. The test of DC bias magnetic current before and after control was also carried out in combination with en- gineering commissioning, which validated the effectiveness of the control measures.