CI-MPC Converter Slashes EV Power Stage Cost with Shared Magnetics

A new topology from researchers Sachith Wijesooriya and Sandun S. Kuruppu tackles one of the biggest pain points in EV powertrain design: the cost, volume, and weight of magnetic components. Their Coupled Inductor-Based Multi-Port DC-DC Converter (CI-MPC) leverages the existing magnetic core—typically used for a boost converter—to create a fully independent and isolated auxiliary converter. Unlike prior designs that only add secondary windings for voltage gain or passive rectification, CI-MPC integrates an actively controlled full-bridge on the secondary side. This allows the auxiliary output to be regulated separately via phase-shift modulation synchronized with the primary switching, while the primary output is controlled through traditional duty-cycle methods.

The result is a unified magnetic framework that delivers two distinct, isolated, and simultaneously regulated DC-DC converters from a single core—eliminating the need for an additional magnetic component or cascaded power stage. A coordinated control framework ensures minimal interaction between the two regulation loops, and avoids the high step-down ratios that plague conventional approaches when drawing low auxiliary voltages from a high-voltage bus. The team validated their design through both simulation and a hardware prototype, demonstrating decoupled regulation, enhanced controllability, and a clear path toward generalized multi-port power conversion. For EV makers, this could mean significant savings in bill-of-materials cost, packaging space, and overall system weight—directly translating to better range and lower vehicle cost.