Multi-Stack PEM Fuel Cell Optimization with PSO-Tuned PI Control
Project Overview
This team project, developed as part of the "Electronic Energy Management Systems" course at the Technical University of Crete, investigates the efficiency of a multi-stack PEM fuel cell energy management system compared to conventional single-stack configurations. The work is based on the research paper "A new control algorithm for increasing efficiency of PEM fuel cells – Based boost converter using PI controller with PSO method" by Y. Benteşen Yakut (International Journal of Hydrogen Energy, 2024).
The core idea is to replace a single high-power fuel cell with multiple smaller fuel cells connected in parallel, sharing a single DC-DC boost converter. A control algorithm dynamically activates or deactivates individual fuel cell stacks depending on load demand, significantly reducing hydrogen consumption — approximately 5x reduction compared to a single-stack system under the same load conditions.
Configuration
5 Parallel PEM Stacks
Five 1.26 kW stacks (13 cells each) replacing a single 6 kW stack (65 cells), sharing one DC-DC converter.
H₂ Reduction
~5x Lower Consumption
Control algorithm activates only the required number of stacks per load, dramatically reducing hydrogen fuel usage.
PI Optimization
PSO Algorithm
Particle Swarm Optimization tunes Kp and Ki parameters of the PI controller, minimizing voltage oscillation at the converter output.
Load Testing
1–6 kW Variable Load
System tested across 7 load levels (1, 2, 3, 4, 4.5, 5, 6 kW) with dynamic fuel cell activation.
System Architecture
The system consists of several key components, each modeled and simulated in MATLAB/Simulink: the PEM fuel cell stacks (mathematically modeled using the Mann model with Nernst voltage, activation, ohmic, and concentration polarization losses), a DC-DC boost converter that steps up the low fuel cell voltage and regulates current distribution, a PI controller that monitors converter output and adjusts the duty cycle to maintain stable voltage, and a switch manager that reads load power and activates the appropriate number of fuel cell stacks.
Key Innovation:
Unlike previous studies that use a separate DC-DC converter for each fuel cell stack, this design uses a single converter for the entire parallel system. The PSO-optimized PI controller adapts dynamically as stacks are added or removed, maintaining output voltage stability within 2% across all load conditions.
Hydrogen Flow Rate Comparison
| Load (kW) | Active Cells | Parallel H₂ (lpm) | Single H₂ (lpm) |
|---|---|---|---|
| 1 | 2 | 1.0 | 6.5 |
| 2 | 3 | 3.0 | 13.75 |
| 3 | 4 | 4.2 | 21.56 |
| 4.5 | 5 | 6.82 | 34.64 |
| 6 | 5 | 9.84 | 50.1 |
Implementation Plan
The project follows a structured implementation plan:
Mathematical modeling of PEM fuel cell using equations (1)–(8) from the reference paper in Simulink.
Design of the DC-DC boost converter with PI controller in Simulink.
Implementation of the switch manager control algorithm for dynamic fuel cell activation.
Design of both single and parallel PEM fuel cell configurations in Simulink.
PSO optimization of PI controller parameters (Kp, Ki) using four objective functions (ISE, ISTE, IAE, ITAE).
Simulation under variable loads and comparison of single vs. parallel performance (hydrogen consumption, voltage oscillation, overshoot, settling time).