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 proposes a distributed phase-shedding method in which each phase is managed by a local controller that determines its activation or deactivation from 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 12 V/1.2 V, 100 A, six-phase converter. 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. The distributed communication architecture also allows faulty modules to be removed and the leader function to be reassigned. These results demonstrate the feasibility of distributed phase shedding as a scalable and fault-tolerant approach for energy-efficient automotive microprocessor power supplies.