变压器励磁涌流成因及抑制措施

Cause and Suppression Method of Transformer Magnetizing InrushCurrent

变压器是移动变电站中的重要设备,其安全与可靠运行非常重要。变压器在正常运行时,励磁电流很小,通常只有额定电流的3%~8%,大型变压器甚至不到1%。可是在空载合闸时,会产生与变压器合闸时电压初相角以及变压器特性有关的励磁涌流。在最不利的情况下,励磁涌流可以达到额定电流的几倍,其最直接的影响就是导致变压器保护装置误动作。因此文章通过分析变电站励磁涌流的形成原因及其影响因素,提出了抑制励磁涌流的措施。

Transformers are important equipment in mobile substations,and their safe and reliable operation is very important.When the transformer is in normal operation,the excitation current is very small,usually only 3%to 8%of the rated current,and even less than 1%for large transformers.However,during no-load closing,there will be an inrush current related to the initial phase angle of the voltage when the transformer is closing and the characteristics of the transformer.In the most unfavorable case,the magnetizing inrush current can reach several times the rated current,and its most direct effect is to cause the transformer protection device to malfunction.In the most unfavorable case,the magnetizing inrush current can reach several times the rated current,and its most direct effect is to cause the transformer protection device to malfunction.Therefore,the causes and influencing factors of inrush current in substation were analyzed,and the measures to restrain inrush current were put forward.