A decoupled controller for fuel cell hybrid electric power split

Abstract

The power management of a hybrid system composed of a fuel cell, a battery and a DC/DC power converter is developed. A decoupled control strategy is proposed, aimed at balancing the power flow between the stack and the battery and avoiding electrochemical damage due to low oxygen concentration in the fuel cell cathode. The controller is composed of two components. The first controller regulates the compressor, and as consequence the oxygen supplied to the cathode, via a classic proportional–integral controller. The second controller optimally manages the current demanded by the fuel cell and battery via linear-quadratic control strategy acting on the converter. The closed-loop performance has been tested both in simulation and in real-time simulation using a microprocessor for the controller.

Keywords:

• fuel cell
• hybrid system
• power management
• optimal control
• hardware-in-the-loop