This article describes an embedded controller for a few-hundred-watt DC power conversion stage, focused on real-time measurement, MPPT control logic, and protection handling.
The design is based on an STM32F334 (timers/ADC well-suited for power control). The firmware acquires bus voltage and current via synchronized ADC sampling, applies basic filtering, and computes instantaneous power for regulation and monitoring.
A closed-loop control implements MPPT by adjusting the converter operating point through PWM duty cycle updates. The power stage includes a boost converter sized for ~48 V class operation, with control features such as soft-start, duty limiting, and fault-driven shutdown.
For protection, an independent path can engage a dump load to clamp bus overvoltage and absorb excess energy when required. Fault handling covers typical events such as overvoltage/overcurrent and temperature-dependent derating (depending on available sensing).
Telemetry and external control are provided through RS485 (Modbus), exposing measurements, state, and fault codes for supervision.