Buck-boost DC/DC converter for aeronautical applications

In this document a DC/DC converter for power conversion between +28V/+270V voltage levels is presented, and the main characteristics of the converter are discussed. The topological structure is first introduced, outlining the hardware components used and the modular approach. The step-down (or Buck) and step-up (or Boost) modulations are then discussed, focusing on the switching signals to drive the low-voltage and high-voltage bridges of the single modules. The description of the control phase follows, justifying the controller used to steer the output voltage towards the desired value. The firmware realized for the converter management is equipped also with a supervision and protection logic, realized as a composition of finite state machines. Finally, simulative results and real measurements are provided to evidence the correctness of the overall topological choices and of the control system realized for the bidirectional converter, focusing also on the comparison between the expected results and those obtained.