A novel fuel cell system design by using Ziegler-Nichols-based intelligent fuzzy controller

This paper proposes a novel fuel cell system design by integrating both methods of Ziegler-Nichols-based PID control and the intelligent fuzzy control, thus the relative stability and disturbance rejection properties can be reserved. This new method is not proposed before for fuel cell control system design. By using PID method for the normal case design of fuel cell stack current command requirement, the overshoot of the temperature was 45%, the temperature rise and the settling times were 0.65 sec and 2 sec, respectively. However, by using intelligent fuzzy Ziegler-Nichols-based PID controller design, the overshoot of the temperature was 12%, the temperature rise and the settling times were 0.7 sec and 1 sec, respectively. Thus the proposed method is better. Moreover, this paper also took the system disturbance variation effect into consideration, e.g. the current requirement was increased by 100% for climbing a slope or speed-up conditions; note a large 60% temperature overshoot was produced by using Ziegler-Nichols based PID controller. But the overshoot was only 20% by using the intelligent fuzzy Ziegler-Nichols-based PID controller. Thus the proposed system is more robust.