Design and operation of a fail-operational 5kW 800V-12V DC-DC converter

The spreading of autonomous drive systems is causing the increase of electrical power request on the 12V vehicle power net because, more and more on-board actuators are realized with electrical drives. Moreover, a very important requirement for autonomous drive systems is the capability of each component to operate also after a failure. A fail operational DC/DC power converter is therefore necessary to achieve the 12V power-net derived from the main battery of electric vehicles. In this paper a fail operational DC-DC 800 V/12 V, 5 kW power converter for automotive application is proposed. The converter topology is designed to ensure operability after a single failure. In this work, the sizing design procedure of each component of the converter is presented. Moreover, a numerical model of the converter is built and used to test the power converter both in normal and faulty conditions. Numerical simulation results validate the proposed topology showing both good dynamic performances and the required fail operational capabilities.