Protection of hybrid transformers in the distribution grid

Due to the increasing integration of renewable energy sources and power electronic loads into the distribution grid, a deterioration of the grid power quality is expected. Consisting of a low frequency transformer and a fractionally rated power electronic converter, the hybrid transformer can be applied to ensure a high power quality by controlling voltage, current, active and reactive power dynamically. For the application in grids with conventional grid protection infrastructure, hybrid transformers have to withstand considerable overvoltage and -current stresses during voltage surges or grid short circuits. Since the semiconductors are less robust than low frequency transformers with respect to these stresses, the effects of possible fault scenarios and a protection concept are studied in this paper.

[1]  J. W. Feltes,et al.  The effect of switching surges on 34.5 kV system design and equipment , 1990 .

[2]  D.G. Holmes,et al.  An integrated approach for the protection of series injection inverters , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[3]  Mighanda Manyahi,et al.  Simplified model for estimation of lightning induced transient transfer through distribution transformer , 2005 .

[4]  J.W. Kolar,et al.  Modeling of Pulse Transformers with Parallel- and Non-Parallel-Plate Windings for Power Modulators , 2007, IEEE Transactions on Dielectrics and Electrical Insulation.

[5]  M. Paolone,et al.  Lightning-Induced Overvoltages Transferred Through Distribution Power Transformers , 2009, IEEE Transactions on Power Delivery.

[6]  D. Gentsch,et al.  New Ultra Fast Earthing Switch (UFES) device based on the vacuum switching principle , 2010, 24th ISDEIV 2010.

[7]  Göran Engdahl,et al.  Simulation and verification of Thomson actuator systems , 2010 .

[8]  M.A.R.M. Fernando,et al.  Lightning surges at distribution transformer secondary , 2010, 2010 5th International Conference on Industrial and Information Systems.

[9]  Subhashish Bhattacharya,et al.  Protection of a transformerless intelligent power substation , 2013, 2013 4th IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG).

[10]  Il-Woo Kim,et al.  Characteristic Analysis and Design of a Thomson Coil Actuator Using an Analytic Method and a Numerical Method , 2013, IEEE Transactions on Magnetics.

[11]  Subhashish Bhattacharya,et al.  Overloading and overvoltage evaluation of a Transformerless Intelligent Power Substation , 2013, 2013 IEEE Power & Energy Society General Meeting.

[12]  Jasmin Smajic,et al.  Simulation and Measurement of Lightning-Impulse Voltage Distributions Over Transformer Windings , 2014, IEEE Transactions on Magnetics.

[13]  Weijie Wen,et al.  Research on Operating Mechanism for Ultra-Fast 40.5-kV Vacuum Switches , 2015, IEEE Transactions on Power Delivery.

[14]  Johann W. Kolar,et al.  Protection of MV/LV solid-state transformers in the distribution grid , 2015, IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society.

[15]  J. Biela,et al.  Evaluation of topologies and optimal design of a hybrid distribution transformer , 2015, 2015 17th European Conference on Power Electronics and Applications (EPE'15 ECCE-Europe).

[16]  F. Blaabjerg,et al.  Frequency-Domain Thermal Modeling and Characterization of Power Semiconductor Devices , 2016, IEEE Transactions on Power Electronics.