Line filter

<h2 id="types-of-line-filters">Types of line filters</h2>

<ul><li>A line filter may be incorporated in a connector. For example:
<ul><li>An AC line filter may be incorporated in a modular <a href="/facts/IEC_60320/nJfaFsJJ">IEC 60320</a> power inlet connector or <a href="/facts/Power_entry_module/X1noNkVV">power entry module</a>.</li>
<li>A telephone line filter may be incorporated in a modular RJ11 connector.</li></ul></li>
<li>A line filter may be mounted on a PCB.</li>
<li>An AC line filter may be a stand-alone device, chassis mounted inside the equipment.</li>
<li>A facility AC line filter is mounted inside a room or cabinet, at the point where the AC power comes in.</li>
<li>For DC grids, photovoltaic applications and EV charging applications, DC filters are used.</li>
<li>AC line filters are very commonly used with inverters (aka drives, frequency converters). The switching semiconductors in the inverters cause energetic noise in high frequencies, that can cause EMI.</li></ul>
<h2 id="characteristics-of-line-filters">Characteristics of line filters</h2>
<ul><li>A line filter may be used to attenuate EMI in either direction. For example:
<ul><li>Emissions: It may be used to reduce the unintentional conducted emission from the equipment, to a level sufficiently low to pass regulatory limits (such as <a href="/facts/FCC/Ueghz8W0">FCC</a> part 15). For example, in switching power supplies.</li>
<li>Immunity: It may be used to reduce the level of EMI entering the equipment, to a level sufficiently low not to cause any undesired behavior. For example, in equipment used in Radio Transmitter facilities</li></ul></li>
<li>The attenuation of line filters is measured in two areas:
<ul><li><a href="/facts/Common-mode_signal/8GCxkDAb">Common mode</a> - attenuation to signals that appear identically on each of the wires going through the filter.<a class="footnote-ref" id="fnref:2" href="#fn:2">2</a></li>
<li><a href="/facts/Differential_mode/jusjFQKo">Differential mode</a> - attenuation to signals that appear on just one of the lines.<a class="footnote-ref" id="fnref:3" href="#fn:3">3</a></li></ul></li>
<li>For each Mode, the attenuation is characterized over the frequency spectrum, and measured in <a href="/facts/Decibel/0LyxAPXh">dB</a>.</li>
<li>AC line filters typically comply to IEC 60939 - Passive filter units for electromagnetic interference suppression<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a></li></ul>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/AC-line_filter_capacitor/7lEg8cDJ">AC-line filter capacitor</a></li></ul>

<h2 id="further-reading">Further reading</h2>
<ul><li>R. Phukan, S. -Y. Chen, D. Dong, R. B. G. Mondal, H. Krupp and S. Nielebock, "Design of a Three-Phase Three-Level Back-To-Back Bridge Interconnection Based Filter Scheme," in IEEE Journal of Emerging and Selected Topics in Power Electronics. doi: 10.1109/JESTPE.2023.3266154</li>
<li>R. Phukan et al., "Enhanced Three-Phase AC Common-Mode Filter With Optimized Damping Network for VFDs," in IEEE Transactions on Industry Applications.doi: 10.1109/TIA.2023.3261859</li>
<li>R. Phukan et al., "Characterization and Mitigation of Conducted Emissions in a SiC based Three-level T-Type Motor Drive for Aircraft Propulsion," in IEEE Transactions on Industry Applications.doi: 10.1109/TIA.2023.3252521</li>
<li>R. Phukan et al., "Optimized DC-AC EMI Filter Design for DC-Fed High Speed SiC-Based Motor Drive," 2022 IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, USA, 2022, pp. 1-8.doi: 10.1109/ECCE50734.2022.9947974</li>
<li>X. Zhao et al., "Design of Rogowski Coil Current Sensor Integrated with Busbar and Gate Driver for 211 kW SiC-Based Three-Level T-Type Inverter," 2022 IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, USA, 2022, pp. 1-7.doi: 10.1109/ECCE50734.2022.9947570</li>
<li>R. Phukan and R. Burgos, "Alternate Filter Structures for Circulating Current and Conducted Noise Mitigation," in <a href="/facts/IEEE_Transactions_on_Power_Electronics/1NtRGarD">IEEE Transactions on Power Electronics</a>, vol. 37, no. 12, pp. 14052-14056, Dec. 2022. doi: 10.1109/TPEL.2022.3198501</li>
<li>R. Phukan, X. Zhao, P. Asfaux, D. Dong and R. Burgos, "Investigation of Staggered PWM Scheme for AC Common Mode Current Minimization in SiC-Based Three-Phase Inverters," in IEEE Transactions on Transportation Electrification, vol. 8, no. 4, pp. 4378-4390, Dec. 2022.doi: 10.1109/TTE.2022.3198528</li>
<li>R. Phukan, D. Nam, D. Dong and R. Burgos, "Design Considerations for a Modular 2-Stage LCLC Filter for Three Phase AC-DC Interleaved Converters," 2022 IEEE Transportation Electrification Conference & Expo (ITEC), Anaheim, CA, USA, 2022, pp. 517-522.doi: 10.1109/ITEC53557.2022.9813883</li>
<li>R. Phukan et al., "A Compact Integrated DM-CM Filter with PCB Embedded DC Current Sensor for High Altitude High Current Applications," 2022 IEEE Transportation Electrification Conference & Expo (ITEC), Anaheim, CA, USA, 2022, pp. 923-928.doi: 10.1109/ITEC53557.2022.9814074</li>
<li>S. Ohn et al., "A Scalable Filter Topology for $N$-Parallel Modular Three-Phase AC–DC Converters by an Arrangement of Coupled Inductors," in <a href="/facts/IEEE_Transactions_on_Power_Electronics/1NtRGarD">IEEE Transactions on Power Electronics</a>, vol. 37, no. 11, pp. 13358-13367, Nov. 2022. doi: 10.1109/TPEL.2022.3179396</li>
<li>R. Phukan et al., "Design of an Indirectly Coupled Filter Building Block for Modular Interleaved AC–DC Converters," in <a href="/facts/IEEE_Transactions_on_Power_Electronics/1NtRGarD">IEEE Transactions on Power Electronics</a>, vol. 37, no. 11, pp. 13343-13357, Nov. 2022. doi: 10.1109/TPEL.2022.3179346</li>
<li>R. Phukan, S. Ohn, S. Nielebock, G. Mondal, D. Dong and R. Burgos, "Comparison Between Interconnected Filter Blocks for Three-Phase AC–DC Interleaved Converters," in IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 10, no. 5, pp. 5956-5968, Oct. 2022. doi: 10.1109/JESTPE.2022.3179335</li>
<li>R. Phukan, S. Ohn, D. Dong and R. Burgos, "An Approach to Localize Circulating Current for Three Phase Interleaved AC-DC Converters," 2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Phoenix, AZ, USA, 2021, pp. 1848-1853.doi: 10.1109/APEC42165.2021.9487128</li>
<li>R. Phukan, D. Nam, D. Dong, R. Burgos, G. Mondal and S. Nielebock, "Highly Integrated Monolithic Filter Building Block for SiC based Three-Phase Interleaved Converters," 2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Phoenix, AZ, USA, 2021, pp. 2876-2882.doi: 10.1109/APEC42165.2021.9487139</li>
<li>R. Phukan, S. Ohn, D. Dong, R. Burgos, G. Mondal and S. Nielebock, "Fault Tolerant Operation of Interleaved Converters using a Bypass Switch Arrangement," 2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Phoenix, AZ, USA, 2021, pp. 2657-2661.doi: 10.1109/APEC42165.2021.9487217</li>
<li>S. Ohn et al., "Modeling of $N$-Parallel Full-SiC AC–DC Converters by Four Per-Phase Circuits," in <a href="/facts/IEEE_Transactions_on_Power_Electronics/1NtRGarD">IEEE Transactions on Power Electronics</a>, vol. 36, no. 6, pp. 6142-6146, June 2021. doi: 10.1109/TPEL.2020.3033708</li>
<li>R. Phukan, S. Ohn, D. Dong, R. Burgos, G. Mondal and S. Nielebock, "Evaluation of Modular AC Filter Building Blocks for Full SiC based Grid-Tied Three Phase Converters," 2020 IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, USA, 2020, pp. 1835-1841.doi: 10.1109/ECCE44975.2020.9236265</li>
<li>S. Ohn et al., "Modular Filter Building Block for Modular full-SiC AC-DC Converters by an Arrangement of Coupled Inductors," 2020 IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, USA, 2020, pp. 4130-4136. doi: 10.1109/ECCE44975.2020.9236309</li>
<li>R. Phukan, S. Ohn, D. Dong, R. Burgos, G. Mondal and S. Nielebock, "Design and Optimization of a Highly Integrated Modular Filter Building Block for Three-Level Grid Tied Converters," 2020 IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, USA, 2020, pp. 4949-4956.doi: 10.1109/ECCE44975.2020.9235895</li>
<li>R. Phukan, L. Wei and J. Hu, "A Low Profile Gate Drive Power Supply," 2019 IEEE Applied Power Electronics Conference and Exposition (APEC), Anaheim, CA, USA, 2019, pp. 3394-3399.doi: 10.1109/APEC.2019.8722106</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">"What is an EMI / RFI Filter?". Curtis Industries. Archived from the original on 2023-02-01. <a href="https://www.curtisind.com/what-is-an-emi-rfi-filter/" target="_blank">https://www.curtisind.com/what-is-an-emi-rfi-filter/</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">"What is an EMI / RFI Filter?". Curtis Industries. Archived from the original on 2023-02-01. <a href="https://www.curtisind.com/what-is-an-emi-rfi-filter/" target="_blank">https://www.curtisind.com/what-is-an-emi-rfi-filter/</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">"What is an EMI / RFI Filter?". Curtis Industries. Archived from the original on 2023-02-01. <a href="https://www.curtisind.com/what-is-an-emi-rfi-filter/" target="_blank">https://www.curtisind.com/what-is-an-emi-rfi-filter/</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">"IEC 60939-1:2010 | IEC Webstore". webstore.iec.ch. Retrieved 2023-10-25. <a href="https://webstore.iec.ch/publication/3947" target="_blank">https://webstore.iec.ch/publication/3947</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
</ol>

Line filter open-in-new

Line filter