公开(公告)号：US09379535B2

公开(公告)日：2016-06-28

申请号：US14524879

申请日：2014-10-27

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Douglas I. Taylor

IPC: H02H7/04 ,  H02H9/00 ,  H01F21/08

CPC classification number: H02H7/04 ,  H02H9/002 ,  Y10T307/826

Abstract: A system for reducing inrush current in a three phase utility transformer upon energization of the transformer by an applied three phase voltage utilizes a pre-flux circuit for establishing residual flux levels in the core segments of the primary windings of the transformer which are near the prospective flux levels established in the core segments by the applied voltage. The pre-flux circuit includes a pre-fluxing capacitor which, after being charged to a predetermined voltage level, is discharged serially through two of the primary windings to establish the predetermined flux levels in the core segments of the two windings, and a reduced flux level in the core segment of the remaining primary winding. The transformer is energized at the instant of positively-referenced peak phase voltage to the third primary winding such that prospective and residual flux approach a near-equal level in all three core segments and inrush current is reduced. The method may be applied to the secondary or tertiary windings instead of the primary windings. Additionally, an alternative method allows application of the pre-fluxing circuit to a delta-connected set of transformer windings.

Abstract translation: 一种用于在通过施加的三相电压通电变压器的情况下减小三相公用变压器中的浪涌电流的系统利用预通量电路来建立变压器初级绕组的铁芯段中的残余磁通量级，其中接近预期 通过施加的电压在芯段中建立的通量水平。 预通量电路包括预充电电容器，其在被充电到预定电压电平之后，串联地通过两个初级绕组放电，以在两个绕组的芯段中建立预定的磁通量，并且减小通量 剩余初级绕组的核心段的水平。 变压器在正相参考的峰值相电压瞬间通电到第三个初级绕组，使得预期和剩余通量在所有三个核心段中达到近似相等的水平，并降低涌流。 该方法可以应用于次级或三级绕组而不是初级绕组。 此外，另一种方法允许将预通量电路应用于三角形连接的变压器绕组组。