隔直装置在直流偏磁治理中的应用研究

Application of the DC Blocking Device on the DC Magnetic Bias Suppression

特高压直流输电采用单极大地模式运行时,流经交流变压器的直流电流会使交流变压器发生直流偏磁。通过分析直流回路的流通路径及电流参数,选择合适的抑制方法,可以有效地解决直流偏磁问题。以酒泉湖南±800 kV特高压直流输电工程酒泉换流站为背景,首先对其周边交流变电站的直流偏磁产生过程及其影响进行分析,然后结合实际测试,对直流偏磁影响情况进行分析,最后对直流偏磁的治理方法进行分析研究。

When the UHVDC(ultra high voltage direct current)transmission using unipolar earth mode,the DC (direct current) current through the transformer in the AC system will produce DC bias.Through the analysis of the flow path and current parameters of the DC circuit,and the appropriate suppression method was chosen which could effectively solve the problem of DC bias.Based on the Jiuquan converter station of the Jiuquan to Hunan ± 800 kV HVDC transmission engineering,firstly,the process of DC bias and its influence on the surrounding AC substation were analysed.Then,the influence of DC bias was analysed by the actual test.Finally,the suppression methods of DC bias were studied.