公开(公告)号：US20210396790A1

公开(公告)日：2021-12-23

申请号：US17467625

申请日：2021-09-07

Applicant: SMA Solar Technology AG

Inventor： Vitali Sakschewski ,  Thorsten Buelo ,  Florian Rauscher

IPC: G01R19/25 ,  G01R29/16 ,  G01R31/42 ,  G01R31/62

Abstract: The disclosure relates to a method and related device for approximately determining voltages at a high-voltage side of a transformer on the basis of measured voltages at a low-voltage side of the transformer. The method includes measuring delta voltages and phase voltages and phase angles at the low-voltage side of the transformer, transforming the phase voltages and phase angles into positive and negative phase sequence system voltages and phase angles of the positive and negative phase sequence systems, respectively, at the low-voltage side, determining positive and negative phase sequence system voltages and phase angles of the positive and negative phase sequence systems, respectively, at the high-voltage side from the positive and negative phase sequence system voltages and phase angles of the positive and negative phase sequence systems, respectively, at the low-voltage side, determining estimated values of a zero phase sequence system voltage and of a phase angle of a zero phase sequence system at the high-voltage side from the measured delta voltages and phase voltages and phase angles at the low-voltage side, and transforming the positive, negative and zero phase sequence system voltages and the phase angles into phase voltages and/or delta voltages at the high-voltage side of the transformer.

公开(公告)号：US11808794B2

公开(公告)日：2023-11-07

申请号：US17467625

申请日：2021-09-07

Applicant: SMA Solar Technology AG

Inventor： Vitali Sakschewski ,  Thorsten Buelo ,  Florian Rauscher

IPC: G01R19/25 ,  G01R31/62 ,  G01R29/16 ,  G01R31/42

CPC classification number: G01R19/2513 ,  G01R29/16 ,  G01R31/42 ,  G01R31/62

Abstract: The disclosure relates to a method and related device for approximately determining voltages at a high-voltage side of a transformer on the basis of measured voltages at a low-voltage side of the transformer. The method includes measuring delta voltages and phase voltages and phase angles at the low-voltage side of the transformer, transforming the phase voltages and phase angles into positive and negative phase sequence system voltages and phase angles of the positive and negative phase sequence systems, respectively, at the low-voltage side, determining positive and negative phase sequence system voltages and phase angles of the positive and negative phase sequence systems, respectively, at the high-voltage side from the positive and negative phase sequence system voltages and phase angles of the positive and negative phase sequence systems, respectively, at the low-voltage side, determining estimated values of a zero phase sequence system voltage and of a phase angle of a zero phase sequence system at the high-voltage side from the measured delta voltages and phase voltages and phase angles at the low-voltage side, and transforming the positive, negative and zero phase sequence system voltages and the phase angles into phase voltages and/or delta voltages at the high-voltage side of the transformer.