公开(公告)号：US10830801B2

公开(公告)日：2020-11-10

申请号：US15886642

申请日：2018-02-01

申请人： Landis+Gyr Innovations, Inc.

发明人： John T. Voisine

IPC分类号： G01R21/133 ,  H01F38/14 ,  H02B1/03 ,  H01F38/34 ,  G01R21/06

摘要： An arrangement includes an A/D converter and a processing circuit. The A/D converter is configured to generate digital samples of voltage and current waveforms in a polyphase electrical system. The processing circuit is operably coupled to receive the digital samples from the A/D converter. The processing circuit configured is to obtain contemporaneous phase current and voltage samples IA, IB, IC and/or IN, and VA, VB, VC. The processing circuit is further configured to determine source leg current sample values based on three of the current samples of IA, IB, IC, and IN, and also based on a ratio of the impedance on one leg of a center-tapped source transformer secondary winding to another secondary winding of a source transformer. The processing circuit is further configured to determine a VA value based at least in part on the source leg current samples. The processing circuit is further configured to provide information representative of the VA calculation to one of a group consisting of a display, a communication circuit, a memory and a billing calculation unit.