基于自身结构改进的变压器直流偏磁抑制措施研究与实现

Research and Implementation Restricting Method of DC Magnetic Bias Induced Current Effects on Transformers Based on Improved Structure

高压直流输电系统中存在直流偏磁问题,直流偏磁产生的谐波会严重危及电网的安全运行。文中基于变压器铁心的直流偏磁特性及变压器自身结构特点提出了一种基于变压器自身结构的变压器直流偏磁抑制措施,达到变压器直流偏磁抑制的目的。首先应用PSCAD软件对试验变压建模并搭建仿真回路进行了原理验证;其次研制了一台变压器模型样机并开展了直流偏磁抑制试验;最后将变压器模型样机与一台同规格变压器进行了性能对比试验研究。试验结果表明,该方法能在不增加变压器损耗、温升的条件下有效抑制变压器直流偏磁,试验数据证明了该方法的有效性和正确性。

DC parallel transmission lines lead to DC bias of converter transformer in the HVDC transmission. The harmonic caused by DC bias disturbs the safe operation of electrical network. Based on DC bias characteristic of transformer and internal structure, the new restricting method is added in way to transformer DC magnetic bias suppression. Firstly, PSCAD software is used to build the model and to make simulation circuit to carry out the principle verification; Secondly, a transformer model prototype is developed and the DC magnetic bias suppression test is carried out; Finally, the transformer model prototype and a transformer with the specifications of the performances are compared. The experimental results show that the scheme can not increase in transformer loss. The method in this design is proved to be effective and efficient one by the results of experiment.