TY - GEN
T1 - A sensor to detect the DC bias of distribution power transformers
AU - Buticchi, Giampaolo
AU - Lorenzani, Emilio
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011
Y1 - 2011
N2 - The widespread use of power converters in low-voltage distribution grids has given rise to issues regarding the power quality. In fact, non-linear loads such as AC Drives, switching-mode power supplies and grid-connected converters can cause, besides the generation of several current harmonics, also a DC current component injection into the grid. This DC current component can lead to magnetic saturation of the distribution power transformers; in this condition, the transformers present distorted current waveforms, increased power absorption and overheating, that can damage the transformer insulations. This paper presents a way to diagnose the magnetic saturation by a non-direct measurement of the DC current component flowing in the power transformer. In other words, the proposed solution provides an information about the total DC injection produced by the sum of all the electric devices connected to the distribution power transformer. The DC current component causes a DC voltage drop across the parasitic resistance of the transformer's winding: sensing this DC voltage drop allows to evaluate the DC current component. A magnetic sensor was developed in order to obtain a great sensitivity, and the implemented closed loop control allowed to guarantee a good linearity with a high rejection ratio of the grid voltage variations. Simulation and experimental results confirm the effectiveness of the proposed approach.
AB - The widespread use of power converters in low-voltage distribution grids has given rise to issues regarding the power quality. In fact, non-linear loads such as AC Drives, switching-mode power supplies and grid-connected converters can cause, besides the generation of several current harmonics, also a DC current component injection into the grid. This DC current component can lead to magnetic saturation of the distribution power transformers; in this condition, the transformers present distorted current waveforms, increased power absorption and overheating, that can damage the transformer insulations. This paper presents a way to diagnose the magnetic saturation by a non-direct measurement of the DC current component flowing in the power transformer. In other words, the proposed solution provides an information about the total DC injection produced by the sum of all the electric devices connected to the distribution power transformer. The DC current component causes a DC voltage drop across the parasitic resistance of the transformer's winding: sensing this DC voltage drop allows to evaluate the DC current component. A magnetic sensor was developed in order to obtain a great sensitivity, and the implemented closed loop control allowed to guarantee a good linearity with a high rejection ratio of the grid voltage variations. Simulation and experimental results confirm the effectiveness of the proposed approach.
UR - http://www.scopus.com/inward/record.url?scp=81255147292&partnerID=8YFLogxK
U2 - 10.1109/DEMPED.2011.6063603
DO - 10.1109/DEMPED.2011.6063603
M3 - Conference contribution
AN - SCOPUS:81255147292
SN - 9781424493036
T3 - SDEMPED 2011 - 8th IEEE Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives
SP - 63
EP - 70
BT - SDEMPED 2011 - 8th IEEE Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives
T2 - 8th IEEE Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives, SDEMPED 2011
Y2 - 5 September 2011 through 8 September 2011
ER -