A CM Filter Configuration for Grid-Tied Voltage Source Converters

Common mode (CM) filters play a crucial role in determining adherence to conducted emissions (CE) standards for grid-tied voltage source converters. Design and implementation of such filters can be challenging since they depend on several factors like identification of CM noise paths, fidelity of passive components and discerning the frequency and amplitude of CM noise sources. In this article, a CM filter has been proposed, which uses passive components along with the converter's heat sink as a circulating return path for the CM currents. Based on the presented CM circuit models with the proposed filter, a detailed design process has been delineated for selecting the passive components required to realize the CM filter. Additionally, the heat-sink potential has been shown to be touch safe during both ideal and nonideal grid conditions with the proposed CM filter. CE spectral results measured using a commercially procured line impedance stabilization network and captured time domain converter operational wave forms for a 2-level, 3$\phi$ grid-tied voltage source converter validate the functionality and effectiveness of the presented design.

[1]  T. Lipo,et al.  Elimination of common mode voltage in three phase sinusoidal power converters , 1996, PESC Record. 27th Annual IEEE Power Electronics Specialists Conference.

[2]  Hans Ertl,et al.  EMI Filter Design for a 1 MHz, 10 kW Three-Phase/Level PWM Rectifier , 2011, IEEE Transactions on Power Electronics.

[3]  Vinod John,et al.  Filter Optimization for Grid Interactive Voltage Source Inverters , 2010, IEEE Transactions on Industrial Electronics.

[4]  M. Liserre,et al.  Design and control of an LCL-filter based three-phase active rectifier , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[5]  Thomas G. Habetler,et al.  Design and implementation of an inverter output LC filter used for dv/dt reduction , 2002 .

[6]  S. Bhattacharya,et al.  Improved Common Mode Noise Models for Three Level T-Type Neutral Point Clamped Converters , 2018, 2018 IEEE Energy Conversion Congress and Exposition (ECCE).

[7]  Vinod John,et al.  Common-Mode Filter Design for PWM Rectifier-Based Motor Drives , 2013, IEEE Transactions on Power Electronics.

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

[9]  Prasad Enjeti,et al.  An improved inverter output filter configuration reduces common and differential modes dv/dt at the motor terminals in PWM drive systems , 1998 .

[10]  Robin J. Evans,et al.  Study of heat sink EMI effects in SMPS circuits , 2001, 2001 IEEE EMC International Symposium. Symposium Record. International Symposium on Electromagnetic Compatibility (Cat. No.01CH37161).

[11]  Mike Rose,et al.  High Frequency Power Distribution Unit (HFPDU) for MRI systems , 2017, 2017 19th European Conference on Power Electronics and Applications (EPE'17 ECCE Europe).

[12]  J. Kolar,et al.  EMI Filter Volume Minimization of a Three-Phase, Three-Level T-Type PWM Converter System , 2017, IEEE Transactions on Power Electronics.

[13]  Dongil Shin,et al.  Quantified Design Guidelines of a Compact Transformerless Active EMI Filter for Performance, Stability, and High Voltage Immunity , 2018, IEEE Transactions on Power Electronics.

[14]  D. Boroyevich,et al.  High power density EMI filter design with consideration of self-parasitic , 2012, 2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[15]  Thomas A. Lipo,et al.  Improvements in EMC performance of inverter-fed motor drives , 1995 .