A finite-element analysis approach to determine the parasitic capacitances of high-frequency multiwinding transformers for photovoltaic inverters

Magnetic components such as transformers and inductors play a significant role in the efficiency and size/weight of inverter. They are also amongst the most difficult components to design, often requiring numerous design interactions and testing. Understanding and accurate prediction of parasitic winding capacitances of high-frequency multiwinding transformers in PV inverters is fundamental to improve performance, lower cost, and speed time to market. Parasitic capacitances are highly dependent on the winding geometry and the proximity of conducting surfaces. As the geometry of the components becomes more complicated, it is almost impossible to derive analytical equations that describe accurately the behavior of magnetic components. Currently, parasitic capacitances of the multiwinding transformers are only known with certainty once a prototype is built. Therefore a design-build-test cycle needs to be iterated, often at substantial cost and time. This paper presents a technique and method to quantitatively predict the parasitic capacitance of high-frequency multiwinding transformer by means of finite-element analysis (FEA). Comparison of the FEA results with a commercially constructed experimental prototype results shows good agreement.

[1]  Oscar Garcia,et al.  Model of the capacitive effects in magnetic components , 1995, Proceedings of PESC '95 - Power Electronics Specialist Conference.

[2]  P. T. Krein,et al.  Minimum Energy and Capacitance Requirements for Single-Phase Inverters and Rectifiers Using a Ripple Port , 2012, IEEE Transactions on Power Electronics.

[3]  Hamid A. Toliyat,et al.  A step-up/down three-phase resonant high-frequency AC-link inverter , 2013, APEC 2013.

[4]  Johann W. Kolar,et al.  Using Transformer Parasitics for Resonant Converters—A Review of the Calculation of the Stray Capacitance of Transformers , 2005, IEEE Transactions on Industry Applications.

[5]  A. Massarini,et al.  Lumped parameter models for single- and multiple-layer inductors , 1996, PESC Record. 27th Annual IEEE Power Electronics Specialists Conference.

[6]  Chen Wei,et al.  More precise model for parasitic capacitances in high-frequency transformer , 2002, 2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289).

[7]  R. S. Balog,et al.  Determination of parasitic parameters in a high frequency magnetic to improve the manufacturability, performance, and efficiency of a PV inverter , 2012, 2012 38th IEEE Photovoltaic Specialists Conference.

[8]  L. Heinemann,et al.  Modeling and accurate determination of winding losses of high frequency transformers in various power electronics applications , 2000, APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.00CH37058).

[9]  J. Kolar,et al.  Using transformer parasitics for resonant converters - a review of the calculation of the stray capacitance of transformers , 2005, Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005..

[10]  W. Marsden.  I and J , 2012 .

[11]  F. Blache,et al.  Stray capacitances of two winding transformers: equivalent circuit, measurements, calculation and lowering , 1994, Proceedings of 1994 IEEE Industry Applications Society Annual Meeting.

[12]  Arthur F. Witulski,et al.  Introduction to modeling of transformers and coupled inductors , 1995 .

[13]  R. S. Balog,et al.  FEA tool approach for determination of parasitic capacitance of the windings in high frequency coupled inductors filters , 2012, 2012 IEEE Power and Energy Conference at Illinois.

[14]  V. A. Niemela,et al.  Calculating the short-circuit impedances of a multiwinding transformer from its geometry , 1989, 20th Annual IEEE Power Electronics Specialists Conference.

[15]  J. Alonso,et al.  A complete transformer electric model, including frequency and geometry effects , 1992, PESC '92 Record. 23rd Annual IEEE Power Electronics Specialists Conference.

[16]  Marian K. Kazimierczuk,et al.  Self-capacitance of inductors , 1997 .

[17]  J.W. Kolar,et al.  Self-Capacitance of High-Voltage Transformers , 2007, IEEE Transactions on Power Electronics.

[18]  J. A. Collins.  An accurate method for modeling transformer winding capacitances , 1990, [Proceedings] IECON '90: 16th Annual Conference of IEEE Industrial Electronics Society.

[19]  A. Schellmanns,et al.  Representing electrical behaviour of transformers by lumped element circuits: a global physical approach , 1999, Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370).

[20]  J.A. Cobos,et al.  Bridging the Gap Between FEA Field Solution and the Magnetic Component Model , 2007, IEEE Transactions on Power Electronics.

[21]  Oscar Garcia,et al.  A full procedure to model high frequency transformer windings , 1994, Proceedings of 1994 Power Electronics Specialist Conference - PESC'94.

[22]  J. Uceda,et al.  Modeling High-Frequency Multiwinding Magnetic Components Using Finite-Element Analysis , 2007, IEEE Transactions on Magnetics.

[23]  Nima Yousefpoor,et al.  Minimisation of total harmonic distortion in a cascaded multilevel inverter by regulating voltages of dc sources , 2012 .