公开(公告)号：US09106076B2

公开(公告)日：2015-08-11

申请号：US13929112

申请日：2013-06-27

Applicant: ABB Technology AG

Inventor： Mika Tausa ,  Kari Vanhala

IPC: H02H3/34 ,  H02H7/045 ,  H02H3/347 ,  H02H3/28

CPC classification number: H02H3/343 ,  H02H3/283 ,  H02H3/347 ,  H02H7/045 ,  H02H7/0455

Abstract: A method in a three-terminal differential protection includes measuring a terminal phase current (IT1(y), IT2(y), IT3(y)) at each terminal (T1, T2, T3) of a protected zone of the differential protection in each phase (L1, L2, L3) to be protected, and determining a bias current (Ib(y)) of the phase on the basis of the terminal phase currents (IT1(y), IT2(y), IT3(y)). The bias current determination includes subtracting phasor values of the terminal phase currents of two terminals from the phasor value of the terminal phase current of one terminal. The terminal phase current, which is a minuend in the phasor difference computation, is selected on the basis of the phase angles or amplitudes of the terminal phase currents.

Abstract translation: 三端差动保护中的方法包括测量差动保护的保护区的每个端子（T1，T2，T3）处的端相相电流（IT1（y），IT2（y），IT3（y）） 根据终端相电流（IT1（y），IT2（y），IT3（y））确定相位的偏置电流（Ib（y））， ）。 偏置电流确定包括从一个端子的端子相电流的相量值中减去两个端子的端子相电流的相量值。 基于相位电流的相位角或振幅，选择相量差计算中的终端相电流。