Piecewise Linear State-Space Modeling and Dimensioning of Protection Circuits for Electronic Semiconductor Fuses

One of the most significant changes in today's automotive low-voltage power supply is replacing melting fuses with electronic, semiconductor-based ones. This substitute is beneficial to meet the requirements for highly automated driving functions and offers advanced, adjustable protection and diagnosis possibilities. The associated increase in switching dynamics can lead to reinforced parasitic effects such as high overvoltage spikes when turning off. These burdens threaten the reliability of the utilized semiconductor components and, thereby, the overall voltage stability of the power supply. Hence, this paper proposes a way to model different overvoltage protection circuits in state-space, ensuring the correct functionality of electronic fuses over varying fault scenarios and environmental stresses. Moreover, these topologies are analyzed and compared with a focus on the impact of the parametrization of associated components based on the dissipation in the power semiconductors. Finally, a step-wise guideline for the practical implementation and parametrization of such a circuit is given.