国华台电主变直流偏磁分析与治理

The Direct Current Magnetic Bias and Control of Guohua Taishan Power Plant's Main Transformer

讨论了直流输电大地电流对国华台电主变压器影响,计算分析比较了电容隔直法、小电阻限流法、反向电流限制法和电位补偿法消除国华台电变压器中性点直流电流的优缺点;在广东省220kV及以上电网的夏季大、小运行方式下,对国华台电1#、2#主变中性点增加电容隔直装置后对现有保护的配置与整定的影响进行分析和校核验证,确定了采用电容法隔直来抑制国华台电主变压器中性点直流电流。

The article discussed the DC power transmission and ground current's impact on Guohua Taishan Power Plant's main transformer,calculated and compared the merits and demerits of the methods of capacitance DC isolation,small resistance current restriction,reverse current restriction and electrical potential compensation in eliminating neutral direct current.In the big and small operation mode in summer of Guangdong Province's 220kV and above electric power grid,analysis and verification of current protection distribution and influence after adding capacitance DC isolation device to the neutral points of Guohua Taishan Power Plant's 1# and 2# transformers are carried out to finally determine that the method of capacitance DC isolation is adopted to prevent neutral direct current in Guohua Taishan Power Plant's main transformer.