Distributed Phase-Shedding: A Scalable Solution for Automotive Microprocessor Power Supplies

The increasing computing power required by autonomous vehicles imposes stringent requirements on automotive microprocessor power supplies in terms of efficiency, scalability, and fault tolerance. Conventional phase-shedding strategies for multiphase converters rely on centralized control, which introduces a single point of failure (SPOF). This paper presents the experimental validation of a distributed phase-shedding method in which each phase is managed by a local controller that determines its activation or deactivation based on local inductor current measurements and communicates with neighboring modules. The proposed strategy is first evaluated through PLECS simulations and then experimentally validated using a hardware-in-the-loop implementation with a six-phase 12 V/1.2 V, 100 A converter. The simulation and experimental results demonstrate stable sequential phase activation and deactivation under slow load variations and rapid activation of all phases under fast load transients, while maintaining balanced phase currents. Experimental measurements further confirm that the distributed phase-shedding strategy maintains the converter within the targeted efficiency range over a wide range of load conditions. Additional fault injection simulations show that the converter can maintain operation after the removal of individual Follower modules. Overall, these results demonstrate the feasibility of distributed phase-shedding as a scalable architecture for energy efficient automotive microprocessor power supplies.