Flatness based control of a Hybrid Power Source with fuel cell / supercapacitor / battery

In this paper, a novel control strategy based on combination of the Flatness based Control Technique (FCT) and the Fuzzy Logic Control (FLC) is developed and investigated to control an Electrical Hybrid Power Source (EHPS). The main property of this strategy is that the system power flow in different operating modes is managed with the same control algorithm (without algorithm commutation). This EHPS is composed of a Fuel Cell system (FC) as the main source and two Energy Storage Devices (ESDs), a bank of SuperCapacitors (SC) and a bank of BATteries (BAT), as the auxiliary sources. Volume and mass of the EHPS can be reduced in this hybridization since the high energy density of the BAT and the high power density of the SC is used. The power flows between the fuel cell, the ESDs and the load is controlled by the FCT and the power sharing between the ESDs (a SC and a BAT) is carried out by the FLC. The power sharing depends on the load power, SOC of the SC and the BAT. To validate the proposed control of the EHPS, the implementation results are presented. The experimental results prove the validity of the proposed approach.