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Analysis Of GaN Based BLDC Motor Drive For Automotive Application
ISSN: 0148-7191, e-ISSN: 2688-3627
Published November 21, 2019 by SAE International in United States
Event: NuGen Summit
Objective Automotive sector is rapidly moving towards electric vehicle. BLDC motor is gaining popularity in the field of electric vehicle due to its high torque to weight ratio and simple control. In this paper we will focus on Switching loss characterization of 3 kW GaN based BLDC drive for electric vehicle. To improve efficiency of drive gallium-nitride based power transistor is used instead of Si MOSFET. GaN devices enable the design of inverter at higher frequencies with improved power density and efficiency as compared to traditional Si MOSFETs. Methodology In this paper commercially available GaN devices compared with Si MOSFETs. The power devices, which are selected for the performance comparison, are EPC2022 GaN by EPC, GS61008P GaN by Gan System and SiDR668DP Si MOSFET by Vishay. The Switching losses analytically predicted in MATHCAD tool and then compared with SPICE simulation losses. Double pulse test circuit is used to find out power losses of power transistors. This double pulse test carried out for two different GaN devices from two manufacturers and one traditional Si mosfet device of same ratings. Comparison between power losses of all three power transistors done. We did comparison between spice switching loss and analytical switching losses. Selection of proper power transistor based on losses has been done in this work. Results After comparing switching losses in SPICE we found out that switching loss for EPC2022 is equals to 98.65 milliwatt, switching loss for GS61008P is equals to 120 milliwatt and switching loss for SiDR668DP is equals to 338 milliwatt. We found out that EPC2022 GaN have lowest losses. It is found that from comparison of analytical & SPICE simulation losses for EPC2022, that for low gate resistance analytical and simulation losses are nearly equal. But with increase in gate resistances analytical losses increase linearly proportional but in simulation there is no significant effect of increasing gate resistances because nonlinear properties of SPICE model. Limitations • As GaN transistors used for high switching frequencies cross conduction must be consider which is not included in this work. • Also PCB lay-outing plays important role in switching losses reduction not included in scope of this work. New Concept compared to others As GaN transistors is new technology research done in this area is limited. This work propose analytical and SPICE simulation method of switching losses calculation in BLDC drive. Conclusion This paper provides analysis of GaN based BLDC motor drive for automotive application. In this paper commercially available GaN devices compared with Si MOSFETs of same rating followed by selection of proper GaN device for BLDC inverter. Results show that there is high potential of a GaN based inverter in a motor drive application.