42V PowerNet in Door Applications

This article describes the effects of a future 42V automotive electrical system on the vehicle electronics, focusing mainly on the consequences for power semiconductors and their associated technologies. Taking the example of a door module, it then shows how existing 14V loads can be operated on the 42V PowerNet and what advantages result for operation of adjusted 42V loads. The following different problem-solving approaches are presented for typical loads such as power windows, electrically positioned and heated outside mirrors, and central locking:

• Power windows: A test motor specially developed for the 42V supply is continuously operated directly from the electrical system using suitable power semiconductors.
• Central locking: A conventional 14V motor is operated at 42V, its operating point being set using pulse width modulation (PWM).
• Remaining door module: Smaller 14V mirror motors and the control electronics are supplied from a second 14V system. This second supply can be taken from the current 14V system or generated locally by appropriate switching regulators, or even by a central DC/DC converter from 42V.