Fuzzy PID control of a stand-alone system based on PEM fuel cell

• Dynamic modeling of the PEMFC validated by Ballard NexaTM Power Module.
• The fuzzy PID control strategy that automatically changes the gains of Kp, Ki and Kd with any load variations, for DC/DC converter and DC/AC inverter of stand-alone applications.
• The control structure of single phase inverter is consisted of two loops in a cascaded structure.
• Frequency analysis of conventional PID controller for inverter was be done in the inner loop (current) and outer loop (voltage).

Fuel cell (FC) systems are appropriate candidates as alternative energy sources for use in stand-alone applications. However, the FC generates an unregulated voltage, which is not suitable in stand-alone application usage solely. This paper presents the control of stand-alone application based on fuzzy PID (FPID) controller. The aim of this paper is designing and controlling a suitable power conditioning unit (PCU) that consists of two DC/DC converter stages and DC/AC inverter. In addition, an analysis of cascade structure based on fuzzy PID controller for a single phase inverter is done and also two feedback control loops are comprised. Inductor current and capacitor voltage are measured and sent through feedback to the inner loop and the outer loop, respectively. Besides, to evaluate the proposed controller robustness, the PCU is considered under step loads as disturbance. Finally, it is shown that the proposed controller has a robust behavior and good transient response.