基于电压与电流微分比值原理的新型变压器保护

为解决变压器差动保护由于励磁涌流而经常误动的问题，从变压器磁特性出发，先阐述了利用磁通特性原理区分励磁涌流的不足，然后提出了利用电源侧电压和电流微分的比值来判别变压器是否含有励磁涌流的新方法。此方法原理简单，易于实现，无需任何先验参数，具有数据采样方便，计算量小，动作可靠、迅速等特点。对变压器各种运行状态进行ATP仿真试验，初步证实了该方法的正确性。最后通过对动模试验数据的分析表明，该方法能够迅速、可靠地切除变压器内部故障，具有很高的实用价值。

RESEARCH ON NOVEL TRANSFORMER PROTECTION BASED ON THE RATIO OF VOLTAGE AND FLUXIONAL DIFFERENTIAL CURRENT

In order to resolve the mal-operation in transformer differential protection due to magnetizing inrush current, this paper introduces the shortcomings of magnetic flux characteristics principle at first. A new method for distinguishing magnetizing inrush current is then put forward based on the ratio of voltage and fluxional differential current. The principle in which none of the anticipated internal parameters is needed is easy to understand and implement. Furthermore, the method is convenient for data acquisition and has less computation, and the protection using this method is reliable and quick. Finally, ATP simulation tests show that the method is reasonable. The results of dynamic analog test confirm that the method is able to clear the internal fault reliably and quickly.