基于广义瞬时功率的新型变压器保护原理

在差有功法的基础上，提出一种利用广义瞬时功率实现变压器保护的新原理。该原理通过消去变压器回路方程中直接体现主磁通的非线性项，构造了仅含漏电感和绕组电阻的二端网络。根据输入端口的广义瞬时功率直流分量的大小，来区分励磁涌流和内部故障电流。该原理避开了励磁涌流和铁损带来的不利影响，计算量小，易于工程实现。经仿真和动模试验验证，新原理能够快速、可靠的切除变压器内部故障，对空投轻微故障也有足够的灵敏度。

A Novel Principle of Transformer Protection Based on Generalized Instantaneous Power

On the basis of power differential method, a novel principle of transformer protection using generalized instantaneous power is presented. By eliminating the mutual flux leakage in the transformer loop equation, a two-terminal network only containing the winding resistance and the leakage inductance is generated. According to the direct current component of the generalized instantaneous power flowing into the two-terminal network, magnetizing inrush and internal fault can be distinguished. The principle is independent of inrush and iron loss and has less calculation burden. Simulation and dynamic testing results verify that this scheme has stability during inrush current and is able to clear internal fault even light fault reliably and quickly.