[{"user_id":"60223","language":[{"iso":"eng"}],"_id":"46269","main_file_link":[{"url":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10173337"}],"date_updated":"2023-08-02T11:30:23Z","publication_status":"published","conference":{"location":"Nürnberg","name":"PCIM Europe 2023","start_date":"2023-05-09","end_date":"2023-05-11"},"author":[{"full_name":"Urbaneck, Daniel","last_name":"Urbaneck","first_name":"Daniel","id":"60223"},{"full_name":"Schafmeister, Frank","last_name":"Schafmeister","first_name":"Frank"},{"first_name":"Joachim","last_name":"Böcker","full_name":"Böcker, Joachim"}],"title":"Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 kW Automotive DC-DC Stage","year":"2023","status":"public","keyword":["LLC Converter","IGBT","ZCS","Synchronous Rectification"],"type":"conference","date_created":"2023-08-02T11:27:32Z","abstract":[{"lang":"eng","text":"State-of-the-art LLC resonant converters use MOSFETs in their inverter stage, which allows high switching frequencies and thus the use of compact magnetic components. The large parasitic output capacitance and the poor reverse-recovery behaviour of the inherent body diode of high-voltage (600 V) silicon MOSFETs require soft switching, i.e. zero-voltage switching (ZVS). Otherwise, the high turn-on switching losses would lead to excessive heating and ultimately to the destruction of the switch. Therefore, MOSFET-based LLC converters are operated in the so-called inductive region only, which enables ZVS. The use of robust and cost-effective IGBTs instead of MOSFETs is particularly advantageous for automotive applications, since in addition to high reliability low costs are an important objective here. Since IGBTs are characterized by dominant turn-off losses and generally higher switching losses compared to MOSFETs, the aim is to operate them with zero-current switching (ZCS) and at low switching frequencies below the resonance frequency. In this region also the voltage transfer characteristic is steeper, which qualifies for applications with a strongly varying input-to-output voltage ratio, such as given for automotive on-board DC-DC converters connecting the (high-voltage) traction battery with the (12 V) auxiliary battery. In this paper, a stress value analysis based on a switched-model simulation is used to design a ZCS LLC converter and take advantage of the mentioned benefits of IGBTs as well as of the steeper voltage transfer characteristic. Within this operation region below the resonance frequency, however, a new phenomenon of several current pulses occurring during a single switching period through the rectifier components may appear. Generally, in applications with high output currents a synchronous rectifier (SR) is often used to keep the conduction losses of the rectifier stage at a moderate level: Low-voltage MOSFETs, which actively need to be gated synchronously to the polarity of the current pulses, are employed then instead of more lossy rectifier diodes. However, standard SR driver ICs have been shown to be unable to properly rectify the multi-pulse output currents of the proposed LLC operation, resulting in high conduction losses of the rectifier stage. A cost-effective hardware concept is presented which ensures proper rectification by using standard SR-ICs that are actively overdriven by the converter’s central microcontroller. A 2 kW prototype for an EV on-board DC-DC converter was built to show the effectiveness of the method, documenting an increase in efficiency by up to 4.1 % compared to a purely SR-IC-based solution. Overall efficiency is very similar to that of a conventional (MOSFET-based) LLC converter so that the ZCS-operated LLC IGBT-converter represents a cost-effective alternative, which even shows 10 % less worst-case losses."}],"citation":{"short":"D. Urbaneck, F. Schafmeister, J. Böcker, in: PCIM Europe 2023, 2023.","ama":"Urbaneck D, Schafmeister F, Böcker J. Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 kW Automotive DC-DC Stage. In: <i>PCIM Europe 2023</i>. ; 2023.","chicago":"Urbaneck, Daniel, Frank Schafmeister, and Joachim Böcker. “Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 KW Automotive DC-DC Stage.” In <i>PCIM Europe 2023</i>, 2023.","bibtex":"@inproceedings{Urbaneck_Schafmeister_Böcker_2023, title={Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 kW Automotive DC-DC Stage}, booktitle={PCIM Europe 2023}, author={Urbaneck, Daniel and Schafmeister, Frank and Böcker, Joachim}, year={2023} }","mla":"Urbaneck, Daniel, et al. “Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 KW Automotive DC-DC Stage.” <i>PCIM Europe 2023</i>, 2023.","apa":"Urbaneck, D., Schafmeister, F., &#38; Böcker, J. (2023). Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 kW Automotive DC-DC Stage. <i>PCIM Europe 2023</i>. PCIM Europe 2023, Nürnberg.","ieee":"D. Urbaneck, F. Schafmeister, and J. Böcker, “Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 kW Automotive DC-DC Stage,” presented at the PCIM Europe 2023, Nürnberg, 2023."},"publication":"PCIM Europe 2023"},{"author":[{"last_name":"Rehlaender","first_name":"Philipp","full_name":"Rehlaender, Philipp","id":"69469"},{"id":"34289","first_name":"Roland","last_name":"Unruh","full_name":"Unruh, Roland"},{"full_name":"Schafmeister, Frank","last_name":"Schafmeister","first_name":"Frank","id":"71291"},{"first_name":"Joachim","orcid":"0000-0002-8480-7295","last_name":"Böcker","full_name":"Böcker, Joachim","id":"66"}],"publication_identifier":{"isbn":["978-1-7281-8950-5"]},"year":"2021","title":"Alternating Asymmetrical Phase-Shift Modulation for Full-Bridge Converters with Balanced Switching Losses to Reduce Thermal Imbalances","publication_status":"published","date_updated":"2023-10-20T11:50:25Z","language":[{"iso":"eng"}],"main_file_link":[{"url":"https://ieeexplore.ieee.org/abstract/document/9487104"}],"doi":"10.1109/apec42165.2021.9487104","publication":"2021 IEEE Applied Power Electronics Conference and Exposition (APEC)","abstract":[{"text":"Phase-shift modulated full bridge converters suffer from thermal imbalances of the inverter switches. The lagging leg switches are subject to larger commutation currents compared to those of the leading leg as the transformer current reduces in the freewheeling interval. Furthermore, after this interval, the energy in the series inductance may not be large enough to achieve zero-voltage switching (ZVS) for the leading leg. Both effects result in thermal imbalances. This paper analyzes the alternating-asymmetrical phase-shift modulation to achieve balanced conduction and switching losses for all four switches while showing that this modulation is easily implemented on standard DSPs. The modulation has been implemented to LLC converters where experimental measurement results proved its effectiveness for LLC converters by reducing the temperature deviation from 6.3 K to only 0.2 K such that the peak temperature is reduced from 95 °C to 92 °C. The paper also proves that the modulation can be utilized to improve the efficiency of LLC converters operated at very low gains while simultaneously reducing the junction temperature of all four switches compared to the conventional complementary modulation. Finally, EMI implications are analyzed, which show that the modulation may be beneficial for reducing the common-mode emissions around the operating frequency.","lang":"eng"}],"date_created":"2022-02-20T21:19:46Z","department":[{"_id":"34"},{"_id":"52"}],"keyword":["Phase-Shifted Full Bridge","Full-Bridge Converter","Phase-Shift Control","Phase-Shift Modulation","LLC Converter","Thermal Balancing"],"type":"conference","conference":{"end_date":"2021-06-17","location":"Phoenix, AZ, USA","start_date":"2021-06-14","name":"2021 IEEE Applied Power Electronics Conference and Exposition (APEC)"},"status":"public","publisher":"IEEE","_id":"29893","user_id":"34289","citation":{"ieee":"P. Rehlaender, R. Unruh, F. Schafmeister, and J. Böcker, “Alternating Asymmetrical Phase-Shift Modulation for Full-Bridge Converters with Balanced Switching Losses to Reduce Thermal Imbalances,” presented at the 2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Phoenix, AZ, USA, 2021, doi: <a href=\"https://doi.org/10.1109/apec42165.2021.9487104\">10.1109/apec42165.2021.9487104</a>.","apa":"Rehlaender, P., Unruh, R., Schafmeister, F., &#38; Böcker, J. (2021). Alternating Asymmetrical Phase-Shift Modulation for Full-Bridge Converters with Balanced Switching Losses to Reduce Thermal Imbalances. <i>2021 IEEE Applied Power Electronics Conference and Exposition (APEC)</i>. 2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Phoenix, AZ, USA. <a href=\"https://doi.org/10.1109/apec42165.2021.9487104\">https://doi.org/10.1109/apec42165.2021.9487104</a>","short":"P. Rehlaender, R. Unruh, F. Schafmeister, J. Böcker, in: 2021 IEEE Applied Power Electronics Conference and Exposition (APEC), IEEE, 2021.","chicago":"Rehlaender, Philipp, Roland Unruh, Frank Schafmeister, and Joachim Böcker. “Alternating Asymmetrical Phase-Shift Modulation for Full-Bridge Converters with Balanced Switching Losses to Reduce Thermal Imbalances.” In <i>2021 IEEE Applied Power Electronics Conference and Exposition (APEC)</i>. IEEE, 2021. <a href=\"https://doi.org/10.1109/apec42165.2021.9487104\">https://doi.org/10.1109/apec42165.2021.9487104</a>.","mla":"Rehlaender, Philipp, et al. “Alternating Asymmetrical Phase-Shift Modulation for Full-Bridge Converters with Balanced Switching Losses to Reduce Thermal Imbalances.” <i>2021 IEEE Applied Power Electronics Conference and Exposition (APEC)</i>, IEEE, 2021, doi:<a href=\"https://doi.org/10.1109/apec42165.2021.9487104\">10.1109/apec42165.2021.9487104</a>.","bibtex":"@inproceedings{Rehlaender_Unruh_Schafmeister_Böcker_2021, title={Alternating Asymmetrical Phase-Shift Modulation for Full-Bridge Converters with Balanced Switching Losses to Reduce Thermal Imbalances}, DOI={<a href=\"https://doi.org/10.1109/apec42165.2021.9487104\">10.1109/apec42165.2021.9487104</a>}, booktitle={2021 IEEE Applied Power Electronics Conference and Exposition (APEC)}, publisher={IEEE}, author={Rehlaender, Philipp and Unruh, Roland and Schafmeister, Frank and Böcker, Joachim}, year={2021} }","ama":"Rehlaender P, Unruh R, Schafmeister F, Böcker J. Alternating Asymmetrical Phase-Shift Modulation for Full-Bridge Converters with Balanced Switching Losses to Reduce Thermal Imbalances. In: <i>2021 IEEE Applied Power Electronics Conference and Exposition (APEC)</i>. IEEE; 2021. doi:<a href=\"https://doi.org/10.1109/apec42165.2021.9487104\">10.1109/apec42165.2021.9487104</a>"}}]