变压器纵联支接阻抗保护

Transformer Longitudinal Tapped Impedance Protection

为了提升变压器保护性能,文中提出了变压器的纵联支接阻抗保护方案。利用变压器两侧电压电流相量计算出变压器纵联支接阻抗,支接阻抗随变压器状态的不同将在阻抗平面上呈现出不同的运行轨迹,本方案根据该特点判断变压器是否故障。该方法不受励磁涌流影响,整定范围很宽,而且对变压器参数的要求低,对于空投于轻微匝间短路故障情况也可以准确判断。仿真实验及动模实验表明该方案能够快速可靠的切除内部故障。

In order to improve the performance of the transformer protection,this paper proposes a new transformer protection scheme which is based on longitudinal tapped impedance. Voltages and currents of both sides of transformer are utilized to calculate the longitudinal tapped impedance,the impedance will present different trajectories for different situations of transformer,this feature can be used to identify the transformer condition. This scheme is not impacted by inrush current,has a wide setting margin and has low demand in parameters of transformer,and the circumstance of transformer closing with an existing slight turn-to-turn fault can also be identified by the proposed method. Simulation and dynamic experiment indicate that this method is able to clear the internal fault quickly and reliably.