A modified LLCL-filter with the reduced conducted EMI noise

For a transformerless grid-tied converter using Pulse Width Modulation (PWM), the harmonics of grid-injected current, the leakage current and the Electromagnetic Interference (EMI) noise are three important issues during design of the output filter. In this paper, the Common-Mode (CM) and the Differential-Mode (DM) EMI noises are investigated for the LCL- and LLCL-filters based single-phase full-bridge grid-tied inverter. Based on this, a modified LLCL-filter topology is proposed to provide enough attenuation on the conducted EMI noise as well as to reduce the DC-side leakage current. The parameter design method of the filter is also developed. The comparative analysis and discussion on four filter cases (the conventional LCL-filter, the conventional LLCL-filter, the modified LCL-filter, and the modified LLCL-filter) are carried out and verified through simulations and experiments on a 0.5 kW, 110 V / 50 Hz single-phase full-bridge grid-tied inverter prototype.

[1]  F. Blaabjerg,et al.  An LLCL Power Filter for Single-Phase Grid-Tied Inverter , 2012, IEEE Transactions on Power Electronics.

[2]  Jian Sun,et al.  Optimal Damping of Multistage EMI Filters , 2012, IEEE Transactions on Power Electronics.

[3]  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).

[4]  Yi Zhao,et al.  Transformerless Inverter With Virtual DC Bus Concept for Cost-Effective Grid-Connected PV Power Systems , 2013, IEEE Transactions on Power Electronics.

[5]  Frede Blaabjerg,et al.  A New Design Method for the Passive Damped LCL and LLCL Filter-Based Single-Phase Grid-Tied Inverter , 2013, IEEE Transactions on Industrial Electronics.

[6]  Wenhua Tan,et al.  A High Frequency Equivalent Circuit and Parameter Extraction Procedure for Common Mode Choke in the EMI Filter , 2013, IEEE Transactions on Power Electronics.

[7]  Jian Sun,et al.  Conducted EMI modeling and mitigation for power converters and motor drives , 2012, 2012 ESA Workshop on Aerospace EMC.

[8]  Remus Teodorescu,et al.  Leakage current evaluation of a singlephase transformerless PV inverter connected to the grid , 2007, APEC 07 - Twenty-Second Annual IEEE Applied Power Electronics Conference and Exposition.

[9]  X. Margueron,et al.  High-Frequency Model of the Coupled Inductors Used in EMI Filters , 2012, IEEE Transactions on Power Electronics.

[10]  Yunjie Gu,et al.  Improved Transformerless Inverter With Common-Mode Leakage Current Elimination for a Photovoltaic Grid-Connected Power System , 2012, IEEE Transactions on Power Electronics.

[11]  F. Blaabjerg,et al.  Review and Comparison of Step-Up Transformerless Topologies for Photovoltaic AC-Module Application , 2013, IEEE Transactions on Power Electronics.

[12]  Thomas A. Lipo,et al.  Pulse Width Modulation for Power Converters: Principles and Practice , 2003 .

[13]  F. Blaabjerg,et al.  A composite passive damping method of the LLCL-filter based grid-tied inverter , 2012, 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG).

[14]  Hojoon Shin,et al.  Low-Common Mode Voltage H-Bridge Converter with Additional Switch Legs , 2013, IEEE Transactions on Power Electronics.

[15]  Yen-Shin Lai,et al.  Effective EMI filter design method for three-phase inverter based upon software noise separation , 2010, The 2010 International Power Electronics Conference - ECCE ASIA -.

[16]  F. Wang,et al.  Analysis of CM Volt-Second Influence on CM Inductor Saturation and Design for Input EMI Filters in Three-Phase DC-Fed Motor Drive Systems , 2010, IEEE Transactions on Power Electronics.

[17]  Remus Teodorescu,et al.  A New High-Efficiency Single-Phase Transformerless PV Inverter Topology , 2011, IEEE Transactions on Industrial Electronics.

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

[19]  Frede Blaabjerg,et al.  Step-by-step design procedure for a grid-connected three-phase PWM voltage source converter , 2004 .

[20]  Holmes,et al.  Pulse width modulation for power converters , 2003 .

[21]  D. Boroyevich,et al.  Influence of high-frequency near-field coupling between magnetic components on EMI filter design , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[22]  Emilio Olias,et al.  Overview of the state of technique for PV inverters used in low voltage grid-connected PV systems: Inverters below 10 kW , 2009 .

[23]  D. Boroyevich,et al.  Leakage Current Reduction in a Single-Phase Bidirectional AC–DC Full-Bridge Inverter , 2012, IEEE Transactions on Power Electronics.