Double loop CDM Controller Design for PEM Fuel Cell power conditioning unit for Voltage Regulation*

Polymer electrolyte membrane fuel cell (PEMFC) possesses the advantage of high current density, but when operated in stand-alone condition it operates at low voltage and the output depends on the working condition. This paper deals with the design of a converter to attain the objective of regulated output voltage under varying operating conditions of load. To obtain the fuel cell parameters, the modeling of PEMFC is done on Nexa 1.2 kW fuel cell adopting an hybrid optimization technique. The output voltage of this model for a certain value of operating current acts as an input source voltage to boost converter. Also, a two loop PID and coefficient diagram method controllers (CDM) are designed for inner current loop and outer voltage loop for regulating output voltage considering the load perturbations. The results obtained by CDM controllers show better robust performance with no overshoot.