A Fault-Tolerant DC-DC Buck Converter with Zero Interruption Time for Autonomous Vehicles

Abstract

A high-end autonomous vehicle is expected to have at least a hundred different electronic subsystems. Each one of them takes power from the battery through Power Management Unit (PMU). Having an efficient PMU is crucial and is expected to supply the required level of uninterrupted power. PMU consists of several buck converters which translate a higher voltage level to required lower voltage levels. A PMU is more reliable if it consists efficient and well-structured voltage converters. In this paper, a fault-tolerant buck converter is designed which outputs 3.3 volts. A simple yet effective technique is proposed to design a fault-tolerant buck DC-DC converter by bypassing the faulty converter leg. The proposed system utilizes a signal processing-based method for fault detection. The secondary converter is activated only upon the confirmed prognosis of a faulty primary converter. Ripple content in the output Aluminum Electrolytic Capacitor (AEC) voltage is monitored and used as a primary health indicator for the converter. An experimental setup is built and tested in the laboratory. Experimental results indicate a smooth transition from the primary converter to the secondary demonstrating an uninterrupted power supply along with the simplicity and effectiveness of the proposed solution.