考虑特高压和复杂接线的直流偏磁风险治理

准东—皖南特高压直流工程是世界上首个±1 100kV特高压输电工程,避免其可能造成的直流偏磁风险意义重大。为此,结合安徽电网规划情况,对接地极附近165km范围内的大地构造调研和现场实测反演得到等效的土壤模型,依据场路耦合理论建立安徽电网交流系统直流电流分布计算模型,计算各个变电站主变中性点电流,分析了直流偏磁对安徽省交流电网影响范围、影响程度及主要的影响因素,并探讨了换流站和特高压站变压器受直流偏磁的影响,针对各电压等级变电站提出直流偏磁抑制措施,制定治理原则,进一步探究综合治理方案,从而使治理效果、治理经济性达到较好的平衡。

DC Bias Mitigation Considering Ultra High Voltage Systems and Sophisticated Connection Modes

The ultra-high-voltage direct current (UHVDC) project of Zhundong-Wannan is the first ±1 100 kV UHVDC project. So it is significant to avoid the possibility of DC bias. First, combing the latest research in the field and according to Anhui power grid planning situation, this paper researches and measures the earth tectonics that is located near the earth electrode of more than 165 km. Secondly, according to the field-coupled model, DC distribution network in AC power network in Anhui province is established. The neutral currents of every substation''s main transformer are calculated and analyzes the sphere of influence, the influence degree and the main influencing factors of DC bias on the AC power grid in Anhui Province. Thirdly, the influences of DC bias on transformers in converter station and UHV Substation are discussed. Finally, different DC bias suppression measures are proposed for converting station of different voltage levels, treatment principles are made, comprehensive disposal plan is further explored to make better balance between the treatment effect and management economy.