基于零模电流与环流比例关系的变压器漏感参数获取方法

从分析变压器暂态涌流特性出发,致力于得到变压器各侧漏感值。首先推导了变压器回路方程,然后得到了原方零模电流和三角绕组环流的比例关系,并求出了自漏感表达式。针对220 kV变压器三角绕组环流无法测量的问题,基于三角绕组环流与原方不饱和相电流平衡的特点,采用原方不饱和相电流代替环流。从而求出零模电流与选定的不饱和相电流的准比例系数,进一步通过判别不饱和时间区间,以该区间内的平均值作为所求的比例系数,最后通过上述表达式计算出自漏感。该方法通过了改进变压器模型仿真验证和现场录波的应用。

Method for obtaining leakage inductance parameter of transformer based on proportional relationship between zero-mode current and circulating current

In order to analyze the transient inrush current characteristics of the transformer, it is necessary to obtain the accurate leakage inductance value on each side of the transformer. In this paper, the transformer loop equation is first deduced, the proportional relationship between the primary zero-mode current and the delta circulating current is got, and the self-leakage expression is obtained. For the problem that the delta winding current of 220 kV transformer cannot be measured, the primary unsaturated phase current is used instead of the circulating current based on the balance of the delta winding circulating current and the primary unsaturated phase current. After determining the quasi-proportional coefficient of the selected unsaturated phase current and the zero-mode current, the unsaturated time interval is further determined, and the average value in the interval is used as the obtained proportional coefficient. Finally, the self-leakage is calculated by the above expression. The improved transformer model simulation and on-site recording verify the method. This work is supported by National Key Research and Development Program of China (No. 2016YFB0900600) and Science and Technology Project of Guangdong Power Grid Co., Ltd. (No. GDKJXM20162461).