Power Electronics Europe Issue 4 - November 2022

www.epc-co.com AUTOMOTIVE POWER 15 www.power-mag.com Issue 4 2022 Power Electronics Europe Design validation results Figure 5 shows a photo of the EPC9165 [6] converter without the heatsink mounted. The dimensions are 4.3x2.8x1.6 inches (108 mm x 70 mm x 40 mm) excluding the edge connectors. With the heatsink installed and 1700 LFM airflow, the converter was operated at 48 V input, 14.3 V output and tested at 500 kHz, and the efficiency results are shown in Figure 6. At 500 kHz, using a 1 µH inductor, the converter achieved a peak efficiency of 97 %. The converter was also tested at 14.3 V input and 48 V output for boost mode operation, as shown in Figure 7. At full load, EPC eGaN FETs can operate with 96 % efficiency at 500 kHz switching frequency, enabling 1 kW/phase compared to silicon-based solutions, which are limited to 600 W/phase due to the limitation on the inductor current at 100 kHz maximum switching frequency. Conclusions With increasing legislation aimed at higher fuel efficiency standards, vehicle manufacturers are searching for cost- effective solutions to meet these demands while still providing the power required for ever-increasing electronically driven functions. This article introduced a bi- directional high power converter for mild- hybrid cars and battery power backup units using four EPC2302 GaN FETs. When converting between 48 V and 14.3 V, the efficiency exceeds 96 % with 500 kHz switching frequency. This scalable solution can be used to meet the power requirements of the latest 48 V mild hybrid systems. References [1] Valdes-Dapena, P. (2022, June 14). Gas prices are rising, so it's a good thing so many vehicles are secretly hybrids. CNN. Retrieved July 21, 2022, from https://www.cnn.com/2022/06/14/cars/ mild-hybrid/index.html [2] Navigant Research (2016, November 2). Global sales of 48-volt systems are expected to reach 9 million in 2025, according to Navigant Research. [Press release] Retrieved July 21, 2022, from https://www.businesswire.com/news/h ome/20161102005098/en/Global- Sales-of-48-Volt-Systems-are-Expected- to-Reach-9-Million-in-2025-According- to-Navigant-Research [3] A. Lidow, M. De Rooij, J. Strydom, D. Reusch, and J. Glaser, GaN Transistors for Efficient Power Conversion, 3rd ed. John Wiley & Sons, 2019. ISBN: 978-1119594147. [4] EPC. (2022). “EPC2302 datasheet,” [Online]. Available: https://epc- co.com/epc/Portals/0/epc/documents/d atasheets/EPC2302_datasheet.pdf [5] MPS (2022). “MPQ1918-AEC1, 100V, 1.6A, 5A, EMI-Optimized Half- Bridge GaN Driver, AEC-Q100 Qualified” [Online]. Available: https://www.monolithicpower.com/en/ mpq1918.html [6] Vishay (2020). “IHTH-1125KZ-5A high current through-hole inductor high temperature series,” [Online]. Available: https://www.vishay.com/docs/34349/ih th-1125kz-5a.pdf [7] Microchip Technology Inc. (2019). 16-bit PIC Microcontrollers Family, [Online]. Available: https://www.microchip.com/ design- centers/16-bit [8] “EPC9165 - 2 kW 48 V/14 V Bi- Directional Power Module Evaluation Board,” Efficient Power Conversion Quick Start Guide LEFT Figure 6: Measured converter efficiency at 500 kHz, 48 V input and 14.3 V output LEFT Figure 7: Measured converter efficiency at 500 kHz, 14.3 V input and 48 V output