Linear Scaling Evaluation of Losses for Automotive Traction Voltage Source Inverters

In this paper, a linear scaling methodology is applied and analyzed for automotive traction voltage source inverters. This is based on the analysis of losses and efficiency. Derived from the theoretical method of classical analysis, three inverters with different power ratings are benchmarked in terms of losses and efficiency. Then, linear scaling is applied to one inverter to acquire up-scaled and down-scaled inverters that reproduce the same power as the other two inverters. The scaled results are compared with those from the classical mathematical results. Simulations show that the error is negligible in the conduction losses. However, in terms of switching losses, the margin of error was from 1%-18%. The latter does not have an impact on the efficiency since the output power of the inverter is much higher than the power that represents the error. The efficiency discrepancy obtained is negligible, with a maximum error of 2%-2.5%. According to the studied model, the simulations results show that linear scaling of losses for traction inverters is feasible as a preliminary design tool.